Radar Warning Receivers

© Brooke Clarke 2001 - 2020

Spy Satellites
Modules instead of packaged diodes
Crystal Video -
    Police Traffic Radar Warning Receivers
            Radar Sentry
            Driver Alert
            X & K Band
            Protector Model 8502 (on Ultrasonic web page)
            Radatron Related Patents
            Reverse Engineering
        Valentine 1
        Police Traffic Speed Radar
        Doppler Modules
        HP 35200A Doppler Radar Module
    Aperiodic non tuned wide band receivers
Test Equipment
    What Is It?
APR-25, APR-26
AGM-45 Shrike Missile
AGM-88 High-Speed Anti-Radiation Missile (HARM)
Polar Frequency Discriminators =  Instantaneous Frequency Measuring
W.W. II Glide Bomb
    M-206 Flare, Aircraft, Countermeasure
    MJU-32A/B Infrared Decoy pyrotechnic Flare
    Brick RR97/AL
    M-1, RR-170AL
    Table of Chaff Cartridges
    Chaff, Flare, Launcher Patents
Radar Man
Radar Cross-Section
    Panoramic (Radio Corp or Labs)

    Cavity Backed Spiral Antennas       
        Vought Aeronautics Antenna Cavity Backed Spiral 218-27510-1 01-54-05080 #CCL362
        AEL Model: ASO111AA Cavity Backed Spiral Antenna

Background and General Information

The Secret History of Silicon Valley (56 minutes) Google Tech Talks, Dec 18 2007 by  Steve Blank is a very interesting overview of Electronic Warfare and how Stanford professor Terman helped develop the west coast infrastructure.  Highly recommended.  The cost in human lives is has a noticable impact on Steve.
Hidden in Plain Sight (1:02:45) at the Computer Museum,   by Steve Blank, Nov 20, 2008  - a very similar talk

The PDF version is as it appeared originally and contains all the illustrations, some of which may be missing or distorted in the html version.
Moon Bounce Elint - PDF - a  CIA paper was SECRET NO FOREIGN,  declassified 2 July 96 - why the Stanford 150 foot dish is one of the best for Moon Bounce ELINT
QUALITY ELINT - PDF - a Feb 1968 CIA paper was SECRET NO FOREIGN,  declassified 2 July 96 - looking at antenna patterns along with actual power levels.
An Elint Vigil, Unmanned - PDF - a  CIA paper was SECRET NO FOREIGN,  declassified 2 July 96 - about the SA-2 SAM system (one of the systems the Limiter Detector was developed) a proposed automatic system (was it deployed?).
Communist Defense Against Aerial Surveillance in Southeast Asia - a  CIA paper was SECRET NO FOREIGN,  declassified 2 July 96 - all illistrations at end of paper
THE OXCART STORY - a  CIA paper was SECRET,  declassified 2 July 96 - about the A-12, aka SR-71
SCIENTIFIC AND TECHNICAL INTELLIGENCE ANALYSIS - a  CIA paper was SECRET,  declassified 2 July 96 - includes mention of SA-2 & SA-6
ELINT a Scientific Intelligence System - PDF - 12 page overview formerly SECRET declassified 22 SEPT 93
The U.S. Hunt for Axis Agent Radios - PDF - Official Use Only declassified 18 SEPT 95 -

The mechanical shutter based APR-25 Radar Warning Receiver was modeled after an early Police Radar Warning Receiver.  So the stories about pilots jury rigging automotive police radar detectors into aircraft may be true.

The carrier based aircraft operating near Vietnam was supposed to turn a manual switch on their Radar Warning Receiver (RWR) to short out the receiver before they left the plane.  They were also not supposed to activate any of their radar's while on deck.  If both of these rules were broken the result would be that the RWR with the switch in the receive position would have it's front end burned out.  The pilot would not know this until he was attacked with no warning from the RWR.

The soviet block surface to air weapons were the SA-x missiles and the ZU-23 gun.
ZU-233 gun

SA-2 Guideline (Wiki: S-75 Dvina)

This was a game changer system that was/is capable of shooting down aircraft flying at over 60,000 feet.  Developed in 1957, shot down a RB-57D (Wiki) over China in 1959 (but they claimed a fighter shot it down).  The first public shoot down was the U-2 of Francis Powers in 1960 (Wiki).

The Spoon Rest early warning radar (Wiki: P-12) operates at VHF.  Note search radars typically operate at low frequencies while tracking/guidance radar's operate at short microwave frequencies.  In 1999 it played a part in shooting down an F-117 (Wiki).  

The Fan Song Fire control & tracking radar (Wiki) operates in what's now called E (2 - 3 GHz), F (3 - 4 GHz)  and G (4 - 6 GHz) bands.

The Radar Warning Receivers and Anti-Radiation Missiles (Wiki), like the Shrike (Wiki, see below) or HARM (see below) were developed to cope with this threat.  This also had a major impact leading to the development of nap-of-the Earth (Wiki) aircraft like the F-111 (Wiki), the A-12 (Wiki) designed from the ground up to have radar stealth (Wiki) capabilities and the start of spy satellites (Wiki: Corona) which was controlled from the Blue Cube (Wiki: Onizuka AF Base) in Sunnyvale, CA.

Spy Satellites

I moved this to the China Lake patents page because the Navy was the father of GPS.


This idea is to use raw diode chips instead of diodes mounted in packages because at microwave frequencies the package parasitics (capacitance and inductance) greatly degrade performance.

At the time I was working at Aertech Microwave and we had just started to make microwave modules.  These were patterned after the HP comb generator and PIN diode switch modules that were cylinders about 1/4" in diameter with glass to metal seals in each end.  The HP design sealed the outer sleeve to the module using a welding process that left the end rough.    This unit had a metal strap forming just under 1 turn that induced current in the sleeve and module bringing them to solder meting temperature within seconds.  To get a good joint HP had a recess that was the mating surface for microwave contact.  This was a difficult thing to make without adding an extra part and so was more expensive than our way of doing it.

I designed our module so that the mating surface was proud of the rest of the module on each end and used a solder process to seal the module.
Rather than use an iron to solder we used a Seven Associates single turn inductive heater with the module held in vertical position so you could see the end under a microscope. A solder pre form was placed in the groove designed for this purpose and the heater start button pressed.  In a few seconds the solder sealed the module.  The module would then be leak tested using Helium.  Helium is the smallest molecule available for leak testing, Hydrogen is a diatomic gas and has a module that's almost twice as big as Helium. Helium leaks out of balloons much easier than hydrogen, that's why mylar helium balloons stay aloft much longer than rubber ones.

R&K 260 Probe StationRucker & Kolls and Micromanulipator were the common analytical probe stations that we used a lot.  These have a level horseshoe ring that moves up and down relative to the chuck.  A stereo zoom microscope and an illuminator would complete the station, plus the probes and test equipment.  The micrometer head sets the down height of the horseshoe.  The black knobs on either side raise or lower the horseshoe.  You can see a double sided socket for a plug-in PCB below the horseshoe and there were (are?) companies that would make up probe cards with the tips where you wanted them so you could use either a plug-in card or individual probes mounted on magnetic mounts, each with it's own positioner.  The knurled knobs in the front are the X-Y stage adjustments.  The black knob at the very front is for stage rotation.

We had a number of different modules in our product line including switches, comb generators, limiters and detectors.  A need came up for a combined limiter detector for a classified military program related to Vietnam.  This was for a Quick Reaction Contract (QRC).  These contracts typically carried a government priority rating of DX-A7.  This meant that we could get our orders delivered before any civilian got his parts and it also meant that the program was watched very closely.

The common RWR at this time was called a "Crystal Video" microwave receiver because it had no RF amplification ahead of the detector and no mixers or Local Oscillators.  An early patent for a Microwave Filter and Detector filed in 1958 and granted 1960 is US 2954468.   You can see that the "filter" grew into a multi band device.

This Detector (no limiter) has a meandered ceramic matching section. I made up a special housing to hold our separate limiter and detector (LD) in a long tube.  On one end was the microwave input SMA(m) connector and on the other end was the connector for the detector output.

I took this prototype up to the Applied Technology Inc. building on a hill in the Stanford Industrial Park.  It had a great view of the Palo Alto bay area.  Inside there was a room with walls formed by chain link fencing that went all the way to the ceiling.  The gate was open and there were men inside carrying snub nose 38 revolvers.

We tested the prototype by applying radar level power levels (accounting for the path loss across a carrier deck) then checked to see of the detector was fried.  It passed.

Limiter-Detecton in a single package.  I bent the leads to get the module to stay upside down on the scanner.  The two black dots to the left are the shunt limiter diodes, then a 1/4 wave ceramic transformer with a Schottky diode mounted at the right end, then a ceramic capacitor.  I next designed a way to package a combined LD in a single longer module and add a housing at the back to hold the factory select bias resistor and blocking capacitor, DC bias terminal and Video output terminal and have the mounting holes and RF connector be in the same place as the original detector.  This was a form, fit and function replacement that included both Limiter and Detector functions..

  This is a reject unit without the rear (right end) cover installed.  The back end housing was made from a piece of square Aluminum stock with a single round cavity (easy to make with a milling machine or screw machine). The printed circuit board (PCB) that went into the housing was circular in shape with a diameter that matched a punch that was already in our machine shop.  The PCB could be made up in advance with a range of the common resistor values used for setting the detector bias and once the operators had determined the correct bias the correct box would be mated to the limiter detector.

The square box contains the bias circuit and positions the DC input and video output connectors in the same location with respect to the mounting holes as the original ATI detector.  The back of the box was bored in a milling machine with a single cylindrical hole.  The PCB was punched using a Rotex so it would be circular and fit the milled hole.
Rotex hole punch

The ALR-xx systems that used these LDs covered a very wide frequency range.  This was handled by using a triplexer (or quadraplexer) to split the input frequency band into narrower bands.  The exact frequencies were classified.  We built the LDs in various bands to match the requirements for each system.

Switched Limiter Det
            Prototype Another version was the Switched Limiter Detector where the limiter DC return was brought out on a connector.  That way you could apply a bias to the limiter diodes turning them on as PIN switches.  This allows the detection of a CW signal.  This is a prototype unit.  An earlier version applied the limiter diode bias from the back end of the module, but that did not work because there was cross talk between the diode drive signal and the detector output.

The modules were tuned in a clean room using various test setups.  Early on we used the Systron Donner small sweep oscillator that had a box full of signal generator heads and switched between them to get a wide band sweep.  The setup included either an HP Scalar Network Analyzer (SNA) or shortly later the 8410 Vector Network Analyzer (VNA).  There were some simple things that could be done to determine how to improve the VSWR by the use of the VNA that were not possible with the SNA.

A good VSWR that was obtained by good matching was far superior to a good VSWR that was obtained by loss.  This made our LDs more sensitive and at the same time they had the limiter to protect from carrier zapping.

The Wild Weasel (Wiki) project is documented in a short movie produced by the Association of Old Crows called "First In, Last Out" that chronicles the early days of the Wild Weasel program.

Crystal Video & Aperiodic receivers

A big advantage of the crystal video receiver is it's simplicity (no local oscillator, no mixer, no IF amp) which also means lower cost than a hetrodyne type receiver.  The down side is that it is not as sensitive.  But for some applications sensitivity is not the key parameter.

All the devices in this paragraph are functionally crystal video receivers, that's to say they are Crystal Radios (Wiki).  Also see my Crystal Radio web page.

A Crystal Video receiver consists of an antenna, detector and video output.  It covers a wide input band and there's no tuning required.  The crystal video detectors on this page were built for specific (often classified) microwave frequency bands (that corresponded with various Surface to Air Missiles or guns).  These typically include a multiband filter (tri-plexer, Quadra-plexer) with a detector optimized for each filter output (see the AM-6536/ALR-54 for an example).

TechLib - Area 50 - The Bug Duster - has two modes: Normal where the antenna feeds a diode so only works for modulated signals, Pseudo-Sinitsa mode that can detect CW carriers.  The 1N5711 is a guard ring Schottky diode and so has much more capacitance than a similar diode without the guard ring.   Changing to a lower capacitance diode should allow operation at higher frequencies.
Crypto Museum - Sinitsa Синица Body-worn intercept receiver - 30 MHz to 1 GHz.  There appears to be a way to detect that one of these receivers is nearby based on the block diagram.

Police Traffic Radar Warning Receivers

The military Radar Warning Receiver components I worked on were for detecting pulse modulated RADAR signals so the input had modulation.  A closely related crystal video receiver was the Fuzz Buster (Wiki) for detecting the CW signal from a police speed RADAR.  It used a couple of W.W.II surplus microwave diodes (1N23?) in a waveguide (Wiki).  One end of the waveguide was the horn antenna.  Just behind the antenna the first diode was modulated by a square wave signal at an audio frequency (1 kHz?).  The audio frequency will not propagate in the wave guide so the second detector diode only responded to the change in strength of the RADAR signal.  A narrow band audio amplifier followed the detector diode.  Note a high Q narrow band audio amplifier followed by a meter is the HP 415 meter.  Although made for VSWR (Wiki) measurements, it's also great for doing lab work on something like a Fuzz Buster.  This is because the narrower the bandwidth the weaker a signal can be detected.

An improvement on using a square wave, like in the Fuz Buster would be to use a pseudorandom (Wiki: PR) on/off modulation and a correlation detector.  This is also called a Lock-In Amplifier (Wiki).  I worked with an engineer from England who used this technique to measure the step response of a steam powered electrical generating plant.  It would be impossible to make a direct measurement since changing the input steam pressure from zero to full blast all at once would destroy the turbine.  So he used a piston on the input steam line to make a very small change to the input pressure.  The piston was modulated with a very long pseudorandom code and a correlator sensed the output.  Analog Devices makes Synchronous Detectors for doing this and AFAICR some of these also have a PR source.  I did not see the part I remembered, maybe it was the ADA2200 or AD630 ?  These can see signals 100dB below the noise level.

The common Boy Scout crystal radio is very similar and uses a tuned tank circuit to select the desired station.

I have a Wi-Fi detector that is a crystal video receiver with an LED bar graph display.  It consists of a patch antenna, a bandpass filter, an RF amplifier and a detector followed by an analog circuit driving a LED bargraph display.

Tunnel (really back diodes) make excellent microwave crystal video detectors because the diode impedance is near 50 Ohms so not only provides very good input microwave frequency matching but also provides a very wide bandwidth output signal source from near 50 Ohms so great for seeing the true shape of narrow pulses.  The common crystal microwave detector that harks back to the 1N23 point contact diode (Wiki) has a high output impedance and so is not good for wide bandwidth signals, like RADAR pulses.

Also see my Bushnell Velocity RADAR Gun.


Radatron was the pioneer company making police radar warning receivers.  They were rather crude, but worked and were the basis of the military RWRs that this page is about.  This may be the first police radar detector.

All the current Radar Sentry and Driver Alert units on eBay look identical to me.  They have a single wire to clip the unit onto a sun visor and are powered by a couple of AA size Mercury batteries.

The first units were called Radar Sentry and Driver Alert (what's the difference?  Let me know).

 Radar Sentry

This photo I received of a Radar Sentry from Pat L.,kc2rnn. shows a sheet metal sun visor clip.  Maybe that's a newer version?

Fig 1 Radar Sentry, with Sheet metal sun visor clip.
Radatron Radar Sentry sheetmetal visor clip
Fig 2 back of different unit
Note wire sun visor clip, 1N2x series W.W.II vintage diodes.
Radatron Radar Sentry sheetmetal visor clip
Fig 3 Inside of battery cover shows:
* Mallory ZM9 Mercury AA size batteries,
* Removable Dielectric Rod antenna.
Radatron Radar Sentry sheetmetal visor clip
Fig 4 the sheet metal sun visor clip looks like it does not belong.
Radatron Radar Sentry sheetmetal visor clip
Fig 5 Behind the bump in the rear plastic cover there are
a couple of 1N2x diodes on a slot antenna for S-Band.
To the right is the working end of the dielectric rod antenna for X-Band.
Radatron Radar Sentry sheetmetal visor clip

 Driver Alert

X & K Band

This is a newer unit that covers a higher frequency band (Ku) than the Radar Sentry or Driver Alert which cover S and X band.
I'm guessing the yellow light/button lights up when a radar is detected and stays lit until it's pressed to silence the alarm.
The red LED is probably a power is connected pilot lamp.  It would be a bad thing if the cigarette lighter plug came loose and you didn't notice.
Unlike FuzzBuster, the X K model has a plastic cover on the horn antenna.
Fig 1
Radatron X K
                      Police Radar Warning Receiver
Fig 2
Radatron X K
                      Police Radar Warning Receiver
Fig 3
Radatron X K
                      Police Radar Warning Receiver

Radatron & related Patents

                      Detector for modulated and unmodulated signals,
                      Hubert H Patterson, George H Webber, AEC,

2901613 Detector for modulated and unmodulated signals, Hubert H Patterson, George H Webber, AEC, 1959-08-25, 329/370; 327/50; 455/337; 455/280 - for 200 to 10,000 MHz. "...three separate components: a broadband antenna, a crystal detector mount, and a high-gain amplifier with provision for either a speaker or earphones."

This is the heart of a crystal video receiver.  Why did the AEC want one in 1957? Let me know.
This patent calls a number of prior art patents for receivers for CW and/or pulse signals, but not microwave.

                      Microwave signal checker for continuous wave
                      radiations, Vernon H Siegel, Radatron R&D
                      Corp, App: 1962-08-03
                      Microwave signal checker for continuous wave
                      radiations, Vernon H Siegel, Radatron R&D
                      Corp, App: 1962-08-03
3094663 Microwave signal checker for continuous wave radiations, Vernon H Siegel, Radatron R&D Corp, App: 1962-08-03, Pub: 1963-06-18, 455/324; 330/10; 342/20; 343/767; 455/130; 455/226.1; 455/325; 455/347; 375/338 - Includes removable dielectric rod antenna, see US7889149.

Fig 1 & 2: Note two W.W.II type diodes mounted on rear wall. Much lower cost than the machined part needed for 2901613 above, but using the idea from it.

Fig 13 & 14 removable dielectric rod antenna.

The Radar Sentry uses two of the Mallory ZM9, Ray-O-Vac M 15 1.35 V Mercury batteries.

2648002 Dielectric antenna, James E Eaton, Navy, 1953-08-04
                      Microwave signal checker for continuous wave
                      radiations, Vernon H Siegel, Radatron R&D
                      Corp, App: 1962-08-03 3094663
                      Microwave signal checker for continuous wave
                      radiations, Vernon H Siegel, Radatron R&D
                      Corp, App: 1962-08-03 3094663
                      Microwave signal checker for continuous wave
                      radiations, Vernon H Siegel, Radatron R&D
                      Corp, App: 1962-08-03
                      Counter-detection system, Vernon H Siegel,
                      Radatron R&D Corp, 1966-06-21

3257659 Counter-detection system, Vernon H Siegel, Radatron R&D Corp, 1966-06-21, 342/20; 342/13 -

Fig 1: a Radar Detector.

Fig 2: Radar Detector at left returns a signal to the police radar (at right) that contains the modulation of the RWR chopper so the police radar can detect that it's being detected.

D194976 Housing for an electro-magnetic wave detector or similar device, William L. Waytena, Radatron R&D Corp,
The design patents does not show a sun visor clip, but otherwise looks like the
Radar Sentry or Driver Alert.

                      Electrical tachometer with saturable core
                      transformer having multi-section windings, Clement
                      R Arrison, Radatron R&D Corp, 1967-07-04

3329892 Electrical tachometer with saturable core transformer having multi-section windings, Clement R ArrisonRadatron R&D Corp, 1967-07-04, 324/169; 324/76.73 -

March 1962 Popular Science ad
March 1962 Popular Science ad

The March '62 ad mentions 1000 hour Mercury battery.
Dual Band means S and X.  But what signal in S-band was there?


When connected to 13.6 VDC nothing happens until the sensitivity knob is turned CW and at some point the light and a tone are heard.  So maybe this is a working unit?

There are two diodes in the waveguide casting.  The diode near the horn antenna (Wiki) is modulated with a square wave and that introduces AM modulation on the CW Doppler Radar (Wiki) signal.  Note that 10.525 GHz is not one of the ISM Bands (Wiki) but rather is allocated for radar use (Frequency Assignments SHF).

The second diode acts as a conventional crystal detector to recover the AM modulation.  There are two fundamentally different ways to demodulate this signal.  The crude way would be to just amplify the detector AC output and use a threshold detector or slightly better add an audio band pass filter.  But a far better way would be to use Lock-in amplifier (Wiki) technology which may have been too complex

Dale Smith is credited as the inventor of the FuzzBuster.  Note it's a huge improvement on the Radatron units in that it has a decent antenna.  Meaning the detection range for the FuzzBuster is much better than the first generation Radatron and probably the second generation Radatron since most people will lose the dielectric rod antenna since it's easy to remove.


Fig 1
Fig 2
Fig 3 The Allen screws lock down the diode position.  They
are adjusted by moving up/down using the rods.
Fig 4 The 4 diodes in the lower right corner make the input polarity
a non issue.  For example if a trucker cuts off the Cig plug he can
connect either wire to + or -.  This may be the first use of a bridge
on a DC input device?
Fig 5 14-pin DIP IC marked:
What is it? Let me know
I've been told it's equivalent to the NTE912

Reverse Engineering


The NTE912 "The NTE912 consists of five general–purpose silicon NPN transistors on a common monolithic substrate in a 14–Lead DIP type package. Two of the transistors are internally connected to form a differentially–connected pair. The transistors of the NTE912 are well suited to a wide variety of applications in low power systems in the DC through VHF range. They may be used as discrete transistors in conventional circuits. However, in addition, they provide the very significant inherent integrated circuit advantages of close electrical and thermal matching."
Pinout table, Notch at top center of table.  Another name for this IC may be CA3086.
It's use is described in App Note 5296, even though the app note is for the CA3018.

Q1 C
Q5 C
Q1 B
Q5 E
Q1/Q2 E
Q5 B
Q2 B
Q4 C
Q2 C
Q4 E
Q3 B
Q4 B
Q3 E
Q3 C
NTE912 pinout

Microwave Diodes

Note the Radatron (see above) uses 1N23 type cartridge diodes but the FuzzBuster is using a much smaller diode.  The brass rods that trap the diodes are 0.0875" dia.  The smaller diodes will have smaller parasitics and will work better at higher frequencies.

The diode near the horn is the modulator and the other the detector.
Diode mode (1.0 mA test current, Fluke 87V DMM)

Black to casting
0.565 V
0.431 V
Red to casting
1.966 V

This implies two different diode types are used.  Maybe a PIN and some type of Detector?
When the FuzzBuster is powered up the AC voltage on the modulator diode is 1.13 VAC and the frequency is about 800 Hz (Fluke 87V DMM).

Valentine 1

This is probably the most sophisticated police radar detector on the market.  See my Cars web page for more.  Mike Valentine makes the Valentine 1 radar detector (factory, my cars page).  Rather than use the old fashioned crystal video detection method he uses a hetrodyne type receiver (Wiki) and processes the Intermediate Frequency (Wiki) in a way similar to a spectrum analyzer.  That's to say the receiver can recognize multiple simultaneous signals and so warn the driver of a number of parameters: is the radar gun in front, at the side or behind you (based on multiple antennas), what frequency band is the radar (based on the design of the LO and IF frequencies), and how many radars (based on counting the peaks in the spectrum analyzer display).   This is the ultimate in police radar detectors.

Police Traffic Speed Radar

The first popular police speed CW Doppler (Wiki) radars operated at 10.525 GHz.  This frequency is used for Doppler motion detection modules like for door openers.  The Fuzzbuster was a crystal video receiver that consisted of a horn antenna followed by a wave-guide with a couple of W.W.II detector diodes.  The first diode was driven with a square wave that added modulation to the incoming signal and the second diode detected the modulated signal.  An AC coupled amplifier made the detected signal large enough to trip an alarm.

Even though these first generation police RWRs were not very sensitive they worked because of the RADAR range equation (Wiki), that's to say the power level at the RWR is inversely dependent on the range squared but the power available to the receiver in the radar gun is inversely dependent on the range to the fourth power, so the RWR is working with a much stronger signal that the radar gun.

The following patents are cited as prior art by Police Doppler Radar speed measuring patents.

2422064 Ground speed indicator (Drift Indicator) , Earl I Anderson, Barco Allen, RCA, 1947-6-10, - Aircraft
2477567 Means for detecting presence and movement of bodies, Eastern Ind Inc, Oct 7, 1944, Aug 2, 1949, - 342/69, 246/30, 342/109, 340/936, 342/114, 340/935, 246/182.00A, 340/552, 342/128, 340/933
2479568 Doppler radar system, William W Hansen, Sperry Corp, App: 1943-08-19, Pub: 1949-08-23, - UHF, involves Doppler processing
2535274 Moving target indicator, Robert H Dicke (Wiki, Pendulums), Sec of War, App: 1945-04-24, - "Doppler effect"

                        Ultrahigh-frequency antenna apparatus, William W
                        Hansen (Wiki), Sperry Corp, 1952-07-08
2602895 Ultrahigh-frequency antenna apparatus, William W Hansen (Wiki), Sperry Corp, 1952-07-08, -
Directly related patents:
2435615 Object detecting and locating system, Russell H Varian, William W Hansen, John R Woodyard, Stanford, App: 1941-09-30
2500178 Ultra high frequency antenna structure
2468751 Object detecting and locating system

This appears to be separate antennas for height finding (left) and azimuth (right).

Naval gun director radar? (Wiki), Mk 37?

2629865 Radio echo apparatus for detecting and measuring the speed of moving objects, Barker John L, Eastern Ind Inc, Jun 13, 1946, Feb 24, 1953, 342/104, 342/165, 246/182.00A, 340/936, 324/76.39, 246/30
2859435 Speed measuring system, Jr John H Auer, Hugh C Kendall, General Railway Signal, 1958-11-04 - measures the speed of a train.
2927319 Short range radar system, William E Bradley, Philco, App: 1957-01-16, - possible because of the new capability of generating 20 uS pulses.
3024443 Traffic speed monitor, Barker John L, Midlock Bernard J, Lab For Electronics Inc, Dec 2, 1958, Mar 6, 1962, 340/936, 340/441, 235/132.00E, 327/77, 235/99.00A, 324/161, 377/9
3118139 Speed measuring apparatus - on car, i.e. a Doppler speedometer
3187329 Apparatus for vehicular speed measurements, Bernard J Midlock, Laboratory For Electronics, App: 1960-09-30 - mounted in what looks like a boat light, waveguide, transistors, 12 VDC power,
3241138 Radar speed meter, Ernest A Zadig, App: 1964-01-28, - to measure the speed of a car.
3703722 Motion detection system with split-ring monostatic doppler detection, David N Gershberg, Alex Y Lee, E Systems, 1972-11-21, - similar to the Rat Race Coupler (Wiki) Where did they use this?  Let me know.
also see Intrusion Alarm Patents - ME-400 -
3990081 Doppler radar device, Serge Guennou, US Philips Corp, 1976-01-20, - locating a Schottky diode in waveguide so that the power to the diode is optimum for Doppler mixing. - Doppler-Fizean effect: Hippolyte Fizeau (Wiki) was involved in the discovery of the Doppler effect.
4157550 Microwave detecting device with microstrip feed line, Martin J. Reid, Robert W. Terry, Alpha Ind, 1979-06-05 - a waveguide detector that works at both 10.525 & 24.124 GHz.
4581769 Radar warning receiver, Richard L. Grimsley, Michael D. Valentine (Cincinnati Microwave, Inc.), Apr 8, 1986 455/226.1, 340/902, 324/76.27, 342/20
5146226 Motor vehicle police radar detector for detecting multiple radar sources, Clarence R. Groth, Stephen R. Scholl, Michael D. Valentine (Valentine Research, Inc.), Sep 8, 1992, 342/20 -


3438031 Doppler radar having digital speed indicator,
RE29401 Method and apparatus for digitally measuring speed
3689921 Method and apparatus for digitally determining the speed of a moving object
3936824 Method and apparatus for digitally measuring speed


4052722 Traffic radar and apparatus therefor

M.P.H. Ind

4214243 Harmonic detector for traffic radar, - inhibit for moving radar (i.e. in moving police car).

Doppler Modules

I seem to remember a number of companies working on Doppler Modules since there were many applications.  Automatic door openers was the highest volume, but alarm systems, vehicle crash avoidance systems were popular until the lawyers nixed that idea.  Aertech was going to make some hardware for a microwave aircraft collision avoidance system, but no bid because of the liability being so high.

                        Doppler radar module employing coupled
                        rectangular waveguides, John W. Davis, Radar
                        Control Systems Inc, 1977-08-16

4042934 Doppler radar module employing coupled rectangular waveguides, John W. Davis, Radar Control Systems Inc, 1977-08-16, -

                        Microwave motion-detection apparatus employing a
                        gunn oscillator in a self-detecting mode, Erno
                        B. Lutz, SOLFAN Systems, 1978-09-26

                        Gunn Diode Doppler module
4117464 Microwave motion-detection apparatus employing a Gunn (Wiki) oscillator in a self-detecting mode, Erno B. Lutz, SOLFAN Systems, 1978-09-26

The Gunplexer (Wiki)  is based on this hardware module.

                        Transmit/receive microwave circuit, Yoichi
                        Kaneko, Kenji Sekine, Eiichi Hase, Akira Endo,
                        Hitachi, 1981-03-31

4259743 Transmit/receive microwave circuit, Yoichi Kaneko, Kenji Sekine, Eiichi Hase, Akira Endo, Hitachi, 1981-03-31 - Doppler speedometer

                        Integrated oscillator and microstrip antenna
                        system, Vincent A. Hirsch, Ball Corp,

4736454 Integrated oscillator and microstrip antenna system, Vincent A. Hirsch, Ball Corp, 1988-04-05, -
                        Short-range radar transceiver employing a FET
                        oscillator, Cheng P. Wen, Richard T. Hennegan,
                        Hughes, 1990-06-05
                        Short-range radar transceiver employing a FET
                        oscillator, Cheng P. Wen, Richard T. Hennegan,
                        Hughes, 1990-06-05 4931799 Short-range radar transceiver employing a FET oscillator, Cheng P. Wen, Richard T. Hennegan, Hughes, 1990-06-05, - Duroid substrate, Gunn diode, power divider (not circulator) . FMCW so can detect range, not simple Doppler.

                        Monolithic microwave transmitter/receiver,
                        Burhan Bayraktaroglu, Natalino Camilleri, TI,

EP0296838 Monolithic microwave transmitter/receiver, Burhan Bayraktaroglu, Natalino Camilleri, TI, 1996-03-27 - IMPATT diode (Wiki),

                        Relating to motion detection units, John
                        Konstandelos, Pyronix, 1999-11-02

5977874 Relating to motion detection units, John Konstandelos, Pyronix, 1999-11-02

EP3091605 Planar antenna microwave module, Hytronik Electronics, 2016-11-09

HP 35200A Doppler Radar Module

 In 1971 HP came out with the 35200A Doppler Radar module.  HP Measure Dec. 1970 - I remember we got one at Aertech for reverse engineering and were amazed that it had a design defect.

HP Doppler Radar
                  module 35200A
The Gunn Diode (Wiki) and it's associated dielectric resonator (Wiki) form at 10.525 GHz oscillator with about 50 mW (+17 dBm) output.
It drives an circulator (Wiki) which passes signals in a clockwise direction.  Oscillator -> Antenna -> Band Pass Filter -> Mixer.

Note the the leakage from the oscillator to the Band Pass Filter will be down by 20 dB, or only 0.5 mW (-3 dBm) to the mixer.

There's a small amount of loss through the band pass filter making it a little worse.  That means the mixer does not have enough power to work and this product was a failure.

PS the HB 100 Doppler module that sells for under $3 on eBay uses a Wilkinson power divider (Wiki) to feed the same amount of power (about 13 dBm) to both the Tx antenna and the mixer.  That extra 10 dB of power (i.w. 10X) makes all the difference between not working and working.

Aperiodic non tuned wide band receivers

The Bug Duster by Wenzel has a Sinitsa (Crypto Museum) mode of operation.  Some possible improvements: 

During W.W. II the aperiodic receiver was invented (see patent #2513384below).  The SSR-201 (Wireless for the Warrior Vol 4) will receive any frequency between 50 kHz and 60 MHz without tuning, i.e. it's a wide open front end.  Also see the free on line book The History of the Radio Intelligence Division Before and During World War II. For example one of these was at the Japanese interment camp at Thule Lake, California (Wiki) and caught the man who had built a transmitter used to talk to other inmates who had regular AM radios.  They used radio transmissions to coordinate a escape attempt.

Below information based on inputs from Brian KN4R:
CIA Reading Room: D.F. Equipment - F.C.C. and F.B.I..pdf  -
* Finch model F-115-A: vehicle mounter, rotatable loop on roof (probably hetrodyne receiver)
* Fada Aperiodic receiver - suitcase size
* Kann Mfg. Co. series K Aperiodic - AC powered, relay to turn on recorder (see YouTube below).

YouTube: WWII Spy Locator Receiver - Aperiodic - Aperiodic Receiver, Type K4 Serial No. 70
Crypto Museum: SSR-201 - The SSR-201 "Watch-Dog"
AperiodicReceiver: Designed and Built by the FCC's Radio Intelliegnce Division During WWII -  the circuit diagram of the SSR-201 seems to indicate that it's essentially a crystal video type receiver.  The antenna drives a 1G4 tube operated as a grid leak detector (rectifier/crystal).  Followed by DC amplification that includes some audio frequencies.

Test Equipment

Sweep Generators

In the beginning Aertech used Alfred Electronics BWO sweep generators, these literally could be used for boat anchors.  They were rack panel width and a couple of feet tall.  Later the HP 690 series sweepers with the plug-in BWO and snap in plastic frequency dial were used.  It was possible to put a number (3?) of plug-ins in one rack and the master in another in order to sweep more than one standard band (standard bands were AFAICR, L = 1 to 2, S = 2 to 4, C = 4 to 8, X = 8 to 12.4, K = 12.4 to 18, Ku = 18 to 26 GHz). Then the Kruse Stork 5000 solid state sweeper came out and it too had a combiner for multiband sweeps.  Then the HP 8350 sweepers came out with a single plug-in for multi-band sweeps and later multi octave band plug-ins.  These had poor phase noise, but for most microwave components work worked well.  You could tie two together for mixer work.  Then there were the synthesized sweep generators with excellent phase noise that were required for precision mixer work.

HP 415E SWR Meter

This is really a very narrow band AC voltmeter centered on 1 kHz.  Maybe a few Hz bandwidth.  When working with weak microwave signals you can 100% AM modulate the RF (either using the internal 1 kHz modulation feature of the sig gen or an external PIN diode modulator) then feed the output from a detector to the 415 meter.  Originally these were used for making slotted line VSWR measurements, but can be used for other applications.

HP 3400 True RMS AC Voltmeter

This is the only meter that I was aware of that could make such a wide band true RMS measurement.  Used for making noise measurements in a number of applications.

Also see my Microwave Test Equipment and Military Test Equipment pages for scalar and network analyzers, noise figure meters, &Etc.


I owe John, WA4WDL, a huge debt of gratitude for making me aware of this.  This came up while learning about the FuzzBuster and the early history of RWRs.  Note that the APS-nn designation is normally used for Airborne Search & Detection Radars. So the first part of this will be looking into the idea that this is a Radar Warning Receiver.  This unit is listed as:
"Tail-Warning Radar System; manufactured by ITT; used in B-47B/E, B-52, B-57, EB-66B, F-101A/C, F-105D, "EF-101B" (Canada)"


Wanted images of any part of the APS-54.  Let me know.
The below images courtesy of John, WA4WDL.

Fig 1 AM-924/APS-54 Amplifier, Video
                  Amplifier, Video
Fig 2 AM-924/APS-54 Amplifier, Video
                  Amplifier, Video

Note there are two Antenna Jacks and
two PRF Lower Limit Selector switches.
It may be that this is the heart of the system.
The antennas may have video outputs instead of RF.
See the AM-6536/ALR-54 RF box which has
video outputs.

What is it?

This is looking into the idea that this is a Radar Warning Receiver, rather than just an Airborne Search & Detection Radar.

The B-47 Stratojet Association - B-47B - "The B-47B carried a K-4A bombing navigation system with a periscope sight in a modified nose, AN/APS-54 warning radar, and AN/APT-5A electronics countermeasures devices"
Vietnam Conflict Aviation Resource Center - Martin B-57 Canberra - "Avionics:   – APW-11 Bombing Air Radar Guidance System, HORAN bombing system, APS-54 Radar Warning Receiver
Joe Baugher - Martin B-57B - "An APW-11 (Radio Museum: 2.8 GHz)Bombing Air Radar Guidance System was provided, helping the pilot to make accurate runs into the target. The Shoran (Wiki) bombing system was added for use by the bombardier/navigator. An APS-54 Radar Warning System was provided, which increased the angle of coverage astern of the aircraft and gave the crew some warning of AI illumination."
QRC - USAF Quick Reaction Capability Programs - QRC-3: J band (Wiki: 10 -20 GHz) antennas for AN/APS-54 radar warning receiver; Hallicrafters; QRC-5: J band antennas for AN/APS-54 radar warning receiver; Hallicrafters, 1953; QRC-11 Selective J band antenna for APS-54 radar warning receiver, Hallicrafters, 1954
The Free Library - First pereson . . . singular. - "There was an APS-54 warning receiver, which was fairly new, and an ALE-1 chaff dispenser, which was not fully tested and which I was not allowed to use."..Col Joseph B. Tyra, USAF (ret.)
Amazon - RF-101 Voodoo Units in Combat (Combat Aircraft Book 127), by Peter E. Davies, Jim Laurier -
"I would have liked to see some coverage of the AN/APS-54 radar warning receiver,  that was replaced by the APR-25/26. The APS-54 was used until 1966 or 1967. It could handle the Fire Can (CIA: 2.7 - 2.86 GHz) and the Fansong (Wiki: S-75, SA-2: Fan Song: 2 - 3 GHz or 4 - 6 GHz) . The radar waveform was fed to the intercom as an audio warning. The APS-54 had two red warning lights on the instrument panel marked "Nose" and "Tail". I spent more time fixing APS-54 problems than my assigned job. The APS-54 had one antenna under the nose radome, and another on the rear tip of the vertical stabilizer cap. The BNC connector from the rear antenna to the stabilizer bulkhead had a habit of pulling apart. Repair usually involved standing on a step ladder on top of a Coleman "Tug" (Wiki) to remove the cap and repair the connector. One of the not so "fun" repair jobs.

The AN/AHN2 audio recorder is mentioned. This was used to record the Radar audio from the APS-54 for debreif and training. This was a Wire recorder. The recording wire was in a cassette. Wire breakage was frequent. You had to unsnarl the mess and splice the wire, then anneal it with a Zippo lighter. Wire recorders were long obsolete at that time. This one was probably used because it was smaller than the available tape recorders."
Radio Nerds - APS List - APS-54* ECM Warning Receiver for B-47,52,57,EB-66, F-101,105 Cape-Farns AS-679,680/APS-54 Antenna Units, 2600-11,000 MC


There may have been a couple of lamps on the pilot's instrument panel marked "Nose" and "Tail" that would light up if the system detected a high PRF (Wiki) indicating the aircraft was being tracked.  Note that search radars have low PRFs so they can have long unambigious ranges, but tracking radars need fast PRFs to quickley detect changes in direction.

Patent 3500401 (see below) may be applicable?

A Guess at the system:


Based on Police Radar Warning Receivers.

1966 vector receiver (the small CRT showed the relative bearing to the threat as the angle from center screen, and the distance from center screen was a relative distance to the threat, made by Itek used to detect: S/X/C-Band Radar Detection and Homing Set; manufactured by Itek; part of AN/ALQ-27; used in A-7E, U-8, U-21, OV-1D, B-52G, RA-5C, A-6E, F-4, F-14, F-100, F-105, C-123, C-130

APR-25 APR-25
Also see the ATI Universal Bench Test Kit for the APR-25 and APR-26 as used in the B-52.

3500401 Radar
                  detection device, Gerald O Miller, Denman R Elliott,
                  Navy (China Lake), App: 1968-07-15,

3500401 Radar detection device, Gerald O Miller, Denman R Elliott, Navy (China Lake), App: 1968-07-15, Pub: 1970-03-10, 342/20; 375/339 -

Patent Citations:
3061795 Flip-flop varies frequency of blocking oscillator, Clarence G Byrd, William K Hagan, IT&T, App: 1958-01-22, Pub: 1962-10-30, - "This invention relates to circuits for indicating the presence of a radio signal, and more particularly to a circuit for indicating the presence of a pulsed radio signal, the indication being sustained for a period of time longer than an individual signal pulse."

3094663 see above Microwave signal checker for continuous wave radiations 

Cited by:

3660844 Radar
                    detector and identifier, Basil E Potter, Sierra
                    Research Corp, 1972-05-02 
 3660844 Radar
                    detector and identifier, Basil E Potter, Sierra
                    Research Corp, 1972-05-02 3660844 Radar detector and identifier, Basil E Potter, Sierra Research Corp, 1972-05-02, 342/20; 455/117; 342/13; 455/229; 375/339 -
4 horn antennas, each for a different frequency band
Also CW and PRF detection,  Output by a number of lights and a single channel of audio

Requires more than 200 or 500 pulses per second.

This may describe the APS-54.

3671964 Automatic
                    radar detection device, Andrew J Trochanowski,
                    Steven A Wicks, Navy

3671964 Automatic radar detection device, Andrew J Trochanowski, Steven A Wicks, Navy342/20 -
blank screen for low pulse rep rates, but alarm and unblank for high pulse rates.

4181910 Portable
                    radar-detecting receiver, Allan B. Hitterdal,
                    Northrop Grumman Sys, 1980-01-01
4181910 Portable
                    radar-detecting receiver, Allan B. Hitterdal,
                    Northrop Grumman Sys, 1980-01-01 4181910 Portable radar-detecting receiver, Allan B. Hitterdal, Northrop Grumman Sys, 1980-01-01, 342/20; 343/774 -

4181910 Portable
                    radar-detecting receiver, Allan B. Hitterdal,
                    Northrop Grumman Sys, 1980-01-01

4440987 Computer and peripheral interface circuit, , Tandy Corp, AST Research Inc, 1984-04-03, -
audio frequency port for modem <-> computer coms

5361069 Airborne
                    radar warning receiver, Robert A. Klimek, Jr., Elias
                    A. McCormac, III, Ronald R. Schambeau, AF, App:

5361069 Airborne radar warning receiver, Robert A. Klimek, Jr., Elias A. McCormac, III, Ronald R. Schambeau, AF, App: 1969-07-18, (Vietnam Era - SECRET), Pub: 1994-11-01,  342/20-

6977611 FM-CW
                    altimeter detector, Ronald T. Crabb, Northrop
                    Grumman Sys, App: 1985-03-04

6977611 FM-CW altimeter detector, Ronald T. Crabb, Northrop Grumman Sys, App: 1985-03-04, (SECRET), Pub: 2005-12-20, 342/122 - detects the very weak FM-CW altimeter signal from aircraft well in front on plane on ground.  Maybe for IFF use?

7148835 Method and apparatus for identifying ownship threats, Jeffrey K. Bricker, Anthony J. Gounalis, James C. Rosswog, Stephen P. Wanchissen, Lockheed Martin, 2006-12-28, 342/20; 342/89; 342/195; 342/175; 342/13 - "A track indication may be provided that indicates at least one source is actively tracking the object based on the received signals and without adjusting the dwell arrangement of the scan strategy for the receiver."


crystal video Radar Warning Receiver made by Itek  Used to sense power-level changes in the L-band command guidance radars of the SAM i.e. a launch detector.
SAM launch warning system
SAM Launch Warning Set; manufactured by Itek; used with AN/APR-25; used in F-100, F-4, U-8, U-21
YouTube: TD Wills: MilViz TacPack F-4E: AN/APR-36 RHAW System Demo -


Homing and Warning ECM Receiver (improved AN/APR-25); manufactured by Itek; used in F-105, EF-4E, A-7, B-52, F-5E/F
IP-957/APR-36 - CRT display showing relative bearing to and type of threat by Applied Technology Inc (ATI) another view - Label -

"early A-10's used the IP-957/APR-36 azimuth indicator as part of the ALR-46 system and the indicator could display alphanumeric symbols as opposed to simple strobes."
- L.M.
IP957 APR36

ECM Signal
Can anyone define for me what the "BG06" SAM signal was and how the EWs "played" with it?  I'm a retired Lt. Col. who flew Ds as a Nav on CAR E-57 during LB II from Andersen.  B...  B,,,,,,

Re: ECM Signal
BG06 referred to the guidance channel for the SA-2 missile. The missile was tracked by the targeting radar and corrections to the missile were up linked to the missile via the BG06.

Since the BG06 antenna was "looking" back at the launch site, the only way to jam it was to be between the missile and the site. To do this, either you were below the missile doing support jamming or you were lucky and the missile missed you.

The radar warning receiver had a launch light to indicate the BG06 was active. My experience was that the light was inaccurate. I looked for the signal on my ECM receiver.

I an unaware of any way to play with it.



Radar Homing And Warning System; used in F-4G; replaced by AN/APR-47
YouTube: on F-4, no sound: MF 14 McDonnell Douglas F-4 Phantom II RPO demo flight test 2:48 -
F-4 Cockpit -


TM11-5841-283-12 Operation & Maint Manual, 150 pages,  is on line at ETM as PIN 053495.pdf
IP-1150 CRT eBay photo
YouTube: RCAF Library: CFSACO [V] 079 APR 39 XEI Demo -
AS-2890/APR-39(V), NSN: 5985-01-026-3927, Mfr: 33439 - is small blade type with SMA-f connector.


C-9326 Detecting set Control
IP-1150 Radar Signal Indicator
CM-440 Comparator
R-1838 Radar Receiver
AS-2892 (left) & AS-2891 (right) Sprial Antennas

AGM-45 Shrike Missile (Wiki)

Made by Texas Instruments.  There were a number of different seeker heads that could be installed, each for a different target (different frequency band).
We made a set of 4 matched detectors for one of these heads.  The one shown is band IX (Wiki).  After properly torquing the SMA nut on the RF (bottom) end a tube with a flange was slide down and the O-ring seated on the tube ID.  The flange was bolted to the guidance section to support the detector in the high vibration environment found on an aircraft wing.  A computerized test system was used to measure hundreds of detectors at a time and output the serial numbers of the matched sets.  We could match much better than the spec using this system and it improved our yield.  (Another version of this test method was later used by ST Microwave to match detectors for a satellite program to extremely tight tolerances.)

Since the frequency band was determined by which guidance section was installed on the missile, the target needed to be known before take off.

The Shrike has the steering wings located at the center of mass of the missile.  This also causes the AIM-7 Sparrow missile (Wiki) to move sideways rather than to rotate.
Wiki: Anti-radiation missile (ARM)

3683385 Direction finding antenna system, U.S. Navy
China Lake, CA,
Aug 8, 1972, 342/447, 343/895

The four detectors are 17, 17', 18 & 18'
3712228 Target marker warhead
China Lake, CA,  Jan 23, 1973
replaces the warhead with a marker
making it easier for others to bomb.
AGM-45 Shrike
                    anti-radiation missile patent 3683385

YouTube: janssen70: AGM-45 Shrike -

AGM-88 High-Speed Anti-Radiation Missile (HARM) (Wiki)

Made by Texas Instruments.  Instead of using detectors tuned to specific threat frequency ranges the HARM has a wide band mixer that can be electronically tuned to the desired frequency.  It's a Superheterodyne receiver (Wiki) not a crystal video receiver.

This is the system where we used the HP 8566B spectrum analyzer to directly measure the spurious mixer products very quickly.  This system was in an access controlled room and had a number of security features.  The test time was reduced dramatically compared to manual testing.  The HARM could be tuned to any desired frequency so one missile could be used for whatever target came up.  Unlike the Shrike AGM-45 above where the seeker head determined the frequency of the radar target.


Replaced by the ALR-67 (Wiki).

2-18 GHz Radar Warning Receiver; manufactured by Litton; used in F-8, F-14, A-4, RA-5C, A-6, EA-6B, A-7, F-100, F-4, F/A-18, CF-104 (Canada)
I think this is the one that we made all the LDs for?
Control - Close Up - Label - 3 buttons for enabling or bypassing the lo, med and high frequency bands, also 3 buttons for Built-In-Test of the three bands and these double as AAA, AAA/AI or AI selectors?


Digital Warning Receiver; manufactured by Litton; used in B-52H, A-7D, A-10, C-130, F-104, F-105G, F-111, F-4, F-5E/F, RU-21H, OV-1, OV-10, HH-53


long-range homing receiver


Until I found this unit on eBay I didn't know the Limiter Detectors we made were used in the ALR-54, but they are.
Radar Warning Receiver for "LAMPS I" system; manufactured by Itek; used in SH-2D/F, SH-3G/H
The AM-6536 uses a number of Aertech Limiter Detectors.
Sikorsky S-70B Seahawk - "Light Airborne Multipurpose System (LAMPS)"

I found the AM-6536/ALR-54 on eBay.  From the photos it looks like the box where the air frame coax cable from one antenna goes to a single TNCm input connector on the AM-6536.  Inside there's the band separation filter and I think this unit has 4 Limiter Detectors.  There's 5 video amplifier boards and some other board with 5 channels, maybe threshold and slope adjustments.  Some reverse engineering will be interesting.  This unit has had a hammer taken to it and it's been stored outside for some number of decades, but I expect it still may be in almost working condition.

Uses the A9X141, A9X142, A9X143 and A9X144 Limiter Detectors.  The overall AM-6536 box has a contract date of 1972.
Dimensions: 6.0 x 6.75 x 3.25 inches  Box made by machining a billet of aluminum that size to remove the cavity inside.  Four of the Video PCBs are fed by the four Limiter Detectors and one video PCB (XA5) gets it's input from the external TNC-male coax connector and since the coax on the inside of that connector has no shield for about 1 inch and it feeds a video amp I'd say it was a fairly low frequency video signal, not RF, not microwave. What was it? let me know

This box was part of the very first LAMPS and has been sitting outside with a cover removed for many decades.  A couple of the transistors on one of the Video PCBs have had their leads rust away allowing the transistor body to be missing.  The conformal coating could not get between the bottom of the transistor and the plastic spacing disk.  The rest of the board where the coating is in tact looks good.  No op amps, no ICs, just discrete parts.  Not sure what the white growth on the aluminum is, but suspect it's related to a salt water atmosphere.

Need to put together a time line for Aertech.  If you know key dates in Aertech's history please let me know.


Used on the F-111
Antenna: AS-2943/ALR-62


0.5-18 GHz Multiband ECM Receiver (improved AN/ALR-59); manufactured by Litton; used in E-2C


(also called the LR-100), a lightweight radar signal receiver designed in-house by Litton Amecom using COTS (commercial-off-the-shelf) components. It can serve as a radar warning receiver (RWR) and also provides precision emitter location and identification (ESM/ELINT) as an electronic support measures (ESM) system.

AN/AAR-60 MILDS (Missile Launch Detection System) (Wiki)

Is Ultraviolet light based.

Polar Frequency Discriminators =  Instantaneous Frequency Measuring

This microwave component is composed of a combination of power spliters and couplers and contains 4 detectors.  One pair of detectors provides either an X value and the other pair provides a Y value for a vector.  The magnitude of the vector is proportional to the amplitude of the incoming signal and the phase angle is proportional to the frequency of the input signal.  In order to get higher frequency resolution you can combine a number of these using delay lines that are increasingly longer so that the frequency is read using a gas meter approach.  In this way you can make an instantaneous frequency measuring (IFM) receiver.  Note that this receiver can determine the frequency of an incoming signal on only one pulse.   We made a number of different models of this device.  they have a frequency range that's no more than an octave, else there would be a frequency ambiguity.
Wide Bnad Systems - makes these
WJ App Note: High Probability of Intercept Receivers in an EW Environment -

W.W. II Glide Bomb

Not really RWR, but this is the closest web page.

Wiki article on Bat (guided bomb).  Patents:
Class 244 Aeronautics and Astronautics
    3.2 Missile Stabilization or Trajectory Control

2764698 Control System, Filing date: Nov 23, 1942 - optical system to control glide bomb
2680578 Glide Bomb, Filing date: Feb 17, 1945 - TV guided
3128061 Automatic self-guidance System for Movable Objects, Filing date: Aug 11, 1945 Issue data Apr 7 1964 -
uses 4 quadrent optical system
1388932 Arial Torpedo - photocell guidance
1447646 Selenium Cell or Bridge, C.W. Cherry - 4 quadrants
1747664 Apparatus for Automatically Training Guns, etc. on Moving Objects - 4 quad optical sensor
2300742 MEASURING AND CONTROL APPARATUS - prevents hunting
2404942 STEERING DEVICE (RCA) 1940
2417112 ELECTRICAL CONTROL SYSTEM, Kettering (GM) Filing date: Jul 3, 1943 - heat seeking aerial bomb
2421085 TARGET SEEKING AERIAL BOMB, (Bendix), Filing date: Jul 12, 1943 - works with reflected IR
2425558 Direction Control Device, - radio control
2431510 Photocell Multiplier Device, (Farnsworth Res), Sep 29, 1944 - photo-multiplier tube with 4 quadrants
2457393 Apparatus for Causation and Prevention of Collisions, G. Muffly,


When I joined (about 1963) Aertech was at 250 Polaris in Mountain View.
196? Aertech moves to 815 Stewart in Sunnyvale (or 825 then 815?)
1968 Aertech at 825 Stewart in Sunnyvale
1984 TRW buys Aertech and even though the FSCM number stays 21847 the name changes to TRW Microwave.
__?__ Deguigne Dr. was another Aertech Building on the corner of Thompson Place.  Across Thompson was AMD.  At the end of Thompson was a heliport, but it was not used.
1987 FEI buys 21847 and the name becomes FEI Microwave
1992 (?) most people are laid off and part of Aertech moves to ST Microwave.
EPA Region 9 Super Fund sites - 825  Note that it's very difficult to tell what building is causing pollution since the ground water moves it.  The only way is to have test wells on at least 4 sides of a building and compare the upstream contamination with the down stream, if they are the same then it's not your building.  Driving around the block of Stewart you can count dozens of test wells.

Flares (Wiki)

Chaff dispensers typically are also used for flares (Wiki).  They are a defense against infrared homing missiles like the Sidewinder developed by China Lake Naval Weapons.
See YouTube for examples of the F-18 launching flares.  This may be what the F-18 intended to do prior to the crash involving a KC-130 tanker.
AP - 2 US warplanes crash off Japan; 1 crew dead, 5 missing, December 6, 2018 -
ProPublica: Faulty Equipment, Lapsed Training, Repeated Warnings: How a Preventable Disaster Killed Six Marines - Video: Adrift- How the Marine Corps Failed Squadron 242 12:11

M-206 Flare, Aircraft, Countermeasure

This has what appears to be a form and fit equivalent of the M-1, Chaff, Countermeasure
1" square body 8" long.

Fig 1
M-206 Flare,
                  Aircraft, Countermeasure
Fig 2
M-206 Flare,
                  Aircraft, Countermeasure
The M-206 Flare has been fired, the tube is empty.  It has fired impulser (primer).  The impulser is electrically triggered rather than triggered by a firing pin.

The M-1 Chaff stick has not been fired, it contains the payload, but is missing the impulser (primer), so is ready to be used.

They are sitting on top of a couple of RR97/AL Chaff Bricks.
Fig 3 Impulser removed from M-206 flare.
Note held in by O-Ring.
Body dia: 0.495"
Body overall Length (excluding blown paper): 0.519
Flange thickness: 0.045"
Flange dia: 0.620"
Center contact recessed: 0.068"
M-206 Flare,
                  Aircraft, Countermeasure
Fig 4 Marked:

M-206 Flare,
                  Aircraft, Countermeasure

Impulser is electrically fired.

MJU-32A/B Infrared Decoy pyrotechnic Flare

Initially I posted this paragraph on the 40mm grenade web page because the shape of the MJU-32 looked like a 40MM round.  Also see the AN-M8 Flare Pistol.
But the igniter has the look and feel of those used on aircraft Chaff and Flare cartridges so this belongs here. 

Flare, Decoy
1370-01-592-1440  LA49

The body OD is 36mm (1.4") and overall length is 148mm (5.8").
The flange at the rear is 1.66mm thick and 37.8mm dia (1.488").
But instead of a small arms primer socket there's what appears to be a recess similar to that used with Chaff and Flare cartridges used in countermeasures.


It appears that flares/chaff with nomenclature starting with MJU- can be used in either the ALE-39 (Citizendium) or ALE-47 (Wiki, Citizendium)  The ALE-47 Counter Measures Dispensing System (CMDSS) is a replacement for the ALE-39 CMDS (FAS).  The magazines that hold the round MJU-32 may be interchangeable with the magazines that hold the square M-206 Flare or M-1 Chaff sticks.  The former is a 1.4" diameter round package and the later is a 1" square package.  But the photos I've seen show a 5 x 6 array for a total of 30 cartridges.  They are all square or all round.

                  Methods and apparatuses for active protection from
                  aerial threats, Northrop Grumman, 2019-10-03, -
This is an enhancement of the ALE-47 that launches rockets instead of chaff or flares.  At first I thought it was the ALE-47, but that's not the case.

20190301839 Methods and apparatuses for active protection from aerial threats, Northrop Grumman, 2019-10-03, -

Fig 2A existing 5x6 ALR-47 magazine holding 30 round cartridges.

Fig 2B is the Eject Vehicle (EV) rocket which is the same size as the existing ALR-47 round cartridge.

The AN/AAR-47 Missile Approach Warning System (Wiki) can trigger the ALE-39 or ALE-47 to launch IR countermeasure flares.  Note the AAR-47 works by detecting the UV signature of the approaching missile.

Fig 1
MJU-32A/B Decoy
                  pyrotechnic Flare
Fig 2
MJU-32A/B Decoy
                  pyrotechnic Flare

Global Security has a page for the MJU-32B Infrared Decoy Flare. "The MJU-32/B Infrared Decoy Flare devices are magnesium-teflon based and produce the same fire ball result as the Mk46 Mod 1c infrared (ir) decoy flares but incorporate a safer igniter design that requires an external ignition source."

The MK46 MOD 1C Decoy Flare is being replaced by the MJU-32/B through attrition.
From Navy Study Material 14313A:

These decoy flares are conventional pyrotechnic Magnesium/Teflon/Viton (MTV) flares that are utilized to decoy IR heat-seeking missiles. These flares are launched from the AN/ALE-39 Countermeasure Dispensing System and AN/ALE-47 Countermeasure Dispensing Set.

The MJU-32A/B and MJU-38A/B are form, fit, and function replacements for the MJU32/B and MJU-38/B. Improvements were made to ignition reliability. These decoy flares consist of a cylindrical aluminum case approximately 5.8 inches long and 1.4 inches in diameter (Figure 4-13).

The base end of the one piece flare case is flanged to a maximum diameter of 1.495 inches to fit the counterbore in the chamber of the dispenser block. The end of the flare case opposite the flanged base is closed with an injected molded polycarbonate end cap attached by a 360 degree crimp. The MJU-32A/B and MJU-38A/B have a (Black) plastic cartridge retainer threaded and sealed into the base of the flare case.

These decoy flares consist of two major elements: the pyrotechnic composition (or flare grain) and the igniter assembly. In the MJU-32/B and MJU-38/B, the complete length of the grain is wrapped with adhesive backed aluminum foil that extends over part of the igniter.

In the MJU-32A/B and MJU-38A/B, the adhesive backed aluminum foil is one-inch wide and covers the gap between the grain and igniter assembly. The igniter assembly contains a plastic body, two ignition pellets, and bore sensing sliders. A silicone rubber pad is located between the end of the flare grain and end cap to provide for variations in longitudinal dimensions of the parts with time. It also provides protection for the internal parts by damping vibration and shock forces. This device requires the CCU-136A/A impulse cartridge for functioning.
MJU-32A/B Infrared
                  Decoy pyrotechnic Flare

Chaff (Wiki)

A RADAR countermeasure developed during W.W.II was then called Window by the British, but Chaff (Wiki) by the U.S.  This consisted of thin strips of Aluminum foil cut to be a half wavelength long.  The trouble was that the strands tended to stick together.  The solution was to use small diameter glass fibers with a metallic coating.  These do not stick together and you can get a lot more of them in the same dispenser volume.
German words that may be related are Düppel or Kunstfadenstraengen.
By 1957 tactical aircraft had Radar Warning Receivers and Chaff (Ref 2). 


In W.W.II a long strip of chaff was called rope.  This was used to confuse long range search radar sets that operated in the HF or VHF frequency range where a 1/2 wavelength is much longer than required for a microwave radar.  This was on eBay with title: VTG Genuine WORLD WAR II CHAFF to Confuse Radar 70 Years Ago - WWII - It appears to be many feet long.
3" x 3" x 5/8" - Does not look like any common dimensions with the RR-97/AL Chaff Brick.
Tape dimensions (see Fig 4).
Plain leader tape thickness: 0.009"
Plain tape wrap radial thickness: 0.110"
Plain Tape ID: 2.80"
Foil tape is in two layers total thickness: 0.001"
Foil Tape OD: 2.775"
Foil Tape ID: 1.422"

Roll Length Calculator:
Plain Tape: 2.8 Meters long, 12.2 Turns.
Foil Tape: 113 Meters long, 676 Turns.

Fig 1 Three wraps of paper to form a streamer.
Chaff Rope
Fig 2
Chaff Rope
Fig 3
Chaff Rope
Fig 4

Chaff Rope

Chaff Brick RR97/AL

This thick paper package (5" x 3" x 2") seems to be designed to tear apart when in windy conditions, like being ejected from an aircraft.  There is a trigger string (see Fig 4 and Fig 5) which I suspect trips a mouse trap (Wiki) mechanism that spreads the contents of the aluminum box.  If you know about these let me know.

The thing that's strange is that these contain aluminum boxes which could damage someone after falling out of the sky.   All the other chaff products I've seen would be harmless to anyone on the ground, but not this one.  Why?  Let me know.

Fig 1 Marked:
RR97/AL (standard nomenclature for chaff container)
190565 (maybe 19 May 1965)
7S7M ?
AF33/657/12145 (AF contract number?)
Fig 2
Fig 3
Fig 4
Fig 5 stamped: 63 C3030

M-1, RR-170AL Chaff Countermeasure

This is a stick type chaff cartridge maybe introduced around 1977.
NSN 5865-01-048-2137
p/n: 9311402
RR-170/AL used on: F-4, F-5, F-15, F-16, A-7, A-10
M-1 used on:Army helicopters
made by Armtec.

1" square body 8-1/8" long.
Fig 1
M-1, RR-170AL
Fig 2
M-1, RR-170AL

Table of Chaff Cartridges

"Countermeasures Chaff Container" may be the correct way to refer to this brick.  Found this information using that search term:
Global Sec
dia x len
Chaff In.
Freq GHz
Easterline NSN

2.5 - 10.5
1958 from Ref-1, 16 oz, foil,


2.5 - 10.5 1958 from Ref-1, Fiber, 3 oz



0.3 - 0.6



2 - 18

5865-00-929-6095 ALE-29A
Mk 46, MJU-8B
1.25x5.8 CCU-136/A
2 - 18


Cyl 1.25x5.8 CCU-41/B
8 - 18
5865-00-160-3964 ALE-29A

1.4" x 6"
1.25x5.8 CCU-136/A

6 - 18 H, I & J bands




A-10, B-l, F-15, F-16, C-5, C-17, C-130, and C-141



2 - 18
1370-01-037-8414 M-130


2 - 18

2 - 18 starting 1990, uses Navy 1x2 stick


NAVAIR 11-120-20 NSWC Crane Draft 1999 Airborne


replaces paper box with plastic box


8 - 18 A-10, F-15, F-16
M206 1x1x8

Ref 1. Chaff Countermeasures and Air Defense RADAR Design, SRI, April 1959, dtic 354894.pdf,
Ref 2. The Air Force in Southeast Asia: Tactics and Techniques of Electronic Warfare, B.C. Nalty, Aug 1977, AFD-110323-034.pdf -

Chaff Dispensers

These bricks do work in the D-21/ALE-27 (Wiki).  These were used in aircraft where the AN/ALR-46 was used, so about equal vintage. 
Overall 39" long x 7" high x 6.5" wide.  Each of the two magazines has about 36" internally available for expendables.  So for a 2" thick package like the RR-97/AL each row can hold about 18 bricks or 36 bricks total.

Fig 1 Handles fold up to make it easy to carry.
Left end is solid.
Right end has holes shown for pusher.  Exit port on bottom.
Fig 2 The two rusty screws at bottom center
of each hole are the package rippers.
There are sheet metal center strips on each side
(2 shown below) between the gear tracks to hold the
expendables slightly away from the tracks.
Fig 3 Trolley to push packages to exit port.
Fig 4 RR-97/AL shown sitting on trolley.
The narrow tie shown pointing up so that
ripper can tear package open.
Fig 5 A ripper for each of the two magazines.
Fig 6
Fig 7

eBay Fig 1
Any electrical interface? No.  This is the Dispenser D-21 which is a part of the ALE-27 system.

eBay Fig 2
The illustration matches the look and feel of the RR-97/AL.

eBay Fig 3
Chaff Dispenser Magazine and Feeder
Mfgs. p/n: 30-1050-1    s/n: 5468
Stock No. 5895-012-7468EA (NSN)
Type:  D-21/ALE 27
Cont. No. OC-65-2  AF36(600) 19515  (1965 Contract date)
Weight:  23.25 lbs.
Proterty of U.S. Gov't.
Electronics & Systems Inc.
Glen Head, N.Y.
Stamp on black paint:  ASS'Y F.T. Feb 11 1965 (data of Fungus Treatment)

eBay Fig 4

The ALE-24 may be the first generation system?
Lundy Electronics & Systems is listed in the 21 October 1989 issue of Electronic Warfare Directory on page 49 showing the ALE-24, ALE-29 (RR-129/RR-144 cartridges, Mk 46/Mk 47 IR flares), ALE-32, ALE-43 (Chaff cutter), ALE-44 (RR-129/Mk 46 flare).

An upgrade of the ALE-39 & ALE-40 dispenser.  The ALE-47 (BAE Systems) may be the a more modern dispenser.
1985 - 1986 the ALE-40 had a problem with inadvertent releases and that was fixed in a 1987 modification.


This would be the first of the ALE Chaff countermeasures sets.  The eBay seller guessed it was from a B-52.
After taking off the rear cover (single Dzus fastener Wiki)) there is a data plate.  Maybe this was to hide what it was.  In the UK they treated Window with a lot of secrecy.

Data Plate:
Control, Countermeasures Chaff Dispenser
Type: C-1280/ALE-1
Govt spec: MIL-D-25180
Volts DC: 24-29
Amps: 6
Contract No.: AF 33(600) 29810
USAF Stock No.: 1660-036 290 571
Mfrs Part No,: G36X6012
Mfrs Serial No.: AF-55-3079
Webster-Chicago Inc., Chicago, Ill., US Property

Webster-Chicago had many patents related to: phonograph players, wire recorders & tape recorders, but none that I could find related to Chaff Dispensers.

Smithsonian National Air and Space Museum: Intervalometer, Countermeasures Chaff Dispenser, TD-93, AN/ALE-1
Data Plate:
Intervalometer, Countermeasures
Mfr's Part No.: RD15100
Type: TD-93/ALE-1
Mfr's Serial No.: AF 54-4491 (?)
Volts DC: 28
Order No.: AF 28063
Stock No.: AF 1660-03/5/4036
Amps: 12
Ryan Industries, Inc. Detroit, Michigan, U.S. Property
                  Intervalometer, Countermeasures
Photo from Smithsonian National Air and Space Museum

Has three 14 socket connectors that look very much like J102.  They are marked:
D Output D-1/ALE-1 or D-2/ALE-2 Output C (for the left two connectors)
A-6 Output B



3 mail pins
Panel Connector: Amphenol 14S-7, 7/8 male thread
Cable Connector: TBD
+28 VDC Input
28 VDC Panel Lights 3ea parallel GE 327


14 sockets
L 20-27 N

Switched DC to Dispenser
Intervalometer Switch
Blue Intervalometer Switch
Red Intervalometer Switch
Green Intervalometer Switch
Green Intervalometer Switch
Blue Intervalometer Switch
Red Intervalometer Switch
Green Signal Lamp & Counter




Controls& Indicators



Continuous: Positions: 1, 2, 3, 4, 5 & 6 - What do the numbers mean?
Intervalometer Positions: A, B, C, D, E & F - What do the letters mean?
A total of 12 Positions

Signal Lamp & Chaff Reserve

Every time a chaff package is ejected the Signal lamp flashes and the Reserve counter decrements by the number of packages ejected (not clear since meaning of Switch is not clear).

Fig 1
Fig 2
Fig 3 Data plate under rear cover.
Fig 4 Down Veeder-Root Counter.

Hackaday: MILSPEC Teardown: C-1282 Chaff Controller - Includes a short video where the lights and counter are triggered.

Boeing's B-47 Stratojet by Alwyn T. Lloyd - pg 237 shows ALE-1
B-52 Stratofortress vs SA-2 "Guideline" SAM: Vietnam 1972–73 yy Peter E. Davies - pg 18 B-52G shows the ALE-1.
World electronic warfare aircraft by Martin Streetly - pg 117 lists
AN/ALE-1:  B-47, B-52 and B-66.
AN/ALE-2: F-100, RB-57 and T-33

The History of US Electronic Warfare: "The renaissance years, 1946 to 1964" by Alfred Price - pg 70: "The ALE-1 was an improved version of the A-6, with a more powerful motor and a more effective system of rollers to ..."

Chaff, Flare, Launcher Patents

2476302 Self-propelled projectile for distributing material, Morris R Jeppson, Army, 1949-07-19
2489337 Aerial reflecting signal target, Sperling Jacob George, US Sec War, 1949-11-29 - allows radar tracking of weather ballons
2832507 Dispensing apparatus, John W Beatty, App: 1953-06-05, Pub: 1958-04-29, 221/112; 221/185; 221/244; 221/253 -
2856185 Dispensing mechanism for packaged window material, Fred L Whipple, USAF, App: 1952-01-16, Pub: 1958-10-14, 221/73; 206/820; 221/32; 225/99 - removes tape from cardboard bricks
2859896 Chaff dispenser Francis M Johnson, USAF, App: 1956-07-20, Pub: 1958-11-11 221/112; 221/253; 221/244 - mechanism for dispensing bricks
2881425 Method of producing radio wave reflector cords of varied length, Charles A Gregory, USN, 1959-04-07, 342/12 -  metal coating on tissue, cellulose, nylon, or other light weight non-conducting material
2898588 Attack deviation device, Connelly L Graham, Northrop Grumman Corp, 1959-08-04,
342/8; 342/9; 273/360 - radar reflector towed behind aircraft
Metal coating of glass fibers at high speeds, John B Eisen, Nachtman John Simon, Bjorksten Johan, Lawrence A Roe, Bjorksten Res Lab Inc, Oct 6, 1959, 65/446, 65/475, 65/468, 118/DIG.220, 264/DIG.190, 65/453
2951410 Tape cutter, Harvey J Brown, Lundy Electronics & Systems, 1960-09-06, 83/304; 83/344; 83/582; 83/595; 83/342; 83/345; 83/591 - ALE-43
2954948 Chaff dispensing system, Francis M Johnson, USAF, App: 1956-04-10, Pub: 1960-10-04 244/136; 221/7; 221/243; 221/15; 221/277 - "..holds a stack of boxes or packages of chaff which are to be dispensed." - may jam when gravity points other than to bottom of box (see 4650092 for improved box dispenser)
2957417 Missile decoy, Daniel D Musgrave, (not assigned), 1960-10-25, 244/3.16; 342/9 - bomber launched defensive missile
3023703 Chaff dispensing device, Beatty John William, 1962-03-06
3027047 Chaff tape cutter, Francis M Johnson, USAF, App: 1956-04-27, Pub: 1962-03-27, 221/30; 83/355; 83/357; 83/923; 102/505; 221/25; 221/73; 342/12 -
3095814 Dispensing apparatus, Tor W Jansen, William B Walker, Navy, 1963-07-02
Fiber winding and fabricating method and machine, Drummond Warren Wendell, Bjorksten Res Lab Inc, Aug 20, 1959, Feb 11, 1964, 156/181, 156/433, 156/166, 28/290, 156/425, 28/289
3126544 W.H. Greatbatch Jr, (not assigned) March 24, 1964, 342/9; 342/12 - lists prior art countermeasure systems - forward fired target missile
3137231 Chaff dispenser system, Francis M Johnson, USAF, App: 1956-06-08, Pub: 1964-06-16 102/351; 342/12; 102/505 - pod with rockets that can be fired ahead of aircraft.
3143965 Chaff dispenser, Pointe Andre E La, Navy, 1964-08-11 - used with meteorological rocket for tracking upper air wind currents.
3150848 Method of decoying a missile from its intended target, Samuel E Lager, 1964-09-29, - IR seeker decoy "mixture of a pyrophoric and an oxidizer together with a suitable inhibiter (vapor depressant) such ,as a polyglycol. "
3221875 Package comprising radar chaff, Elmer G Paquette, USAF, 1965-12-07 342/12; 102/357; 57/13; 102/505 - Bundle of metal coated glass fibers
3263563 Flare ignition device, Harvey J Brown, Lundy Electronics & Systems, 1966-08-02, 89/1.51; 102/342 - expendable package looks like 5x3x2".

3473472 Photoflash
                  cartridge, Billy R Bliss, Clarence W Gilliam, John E
                  Laswell, US Navy, 1969-10-21

3473472 Photoflash cartridge, Billy R Bliss, Clarence W Gilliam, John E Laswell, US Navy, 1969-10-21, 102/346 -

3494163 Automatic coiling apparatus, Edward M Wight, Tracor Aerospace Inc, 1970-02-10, 72/129; 72/196; 242/535.3; 72/146; 242/413.2 -
3500409 Means for packaging and dispensing chaff, Burns A Cash, USAF, 1970-03-10, 342/12; 102/386; 102/357 - cap is caught by air and pulls chaff out of weighted container.
3557698 Photoflash bomb, David Hart, Henry J Eppig, Garry Weingarten, US Army, App: 1953-01-28, (20 year delay) Pub: 1971-01-26, 102/336; 102/382 -
3566852 Spring-type end-weighted rope reel chaff dispenser, Ramon I Padron, USAF, 1971-03-02, 124/6; 124/7; 221/92 -
3648350 Method of forming coil packages of metal foil strips, Patrick E Cassidy, Philip S Lowell, Tracor Aerospace Inc, 1972-03-14, 29/423; 156/155; 156/191; 428/906 - 
3708563 Magazine for aerial dispenser and method of making same, P Sells, 1973-01-02, 264/46.5; 89/1.816; 264/46.7; 264/255; 89/1.59; 264/46.6; 264/46.9; 264/277 - maybe the start of the 5x3x2" box?
3715754 Tethered chaff strand countermeasure with trailing end kite, J Parry, USAF, 1973-02-06, 342/12 -  
3721196 Chaff dispensing system, E Willis, L Musser, J Seagraves, 1973-03-20
3730098 Apparatus for quick-blossoming chaff ejection, W Edwards, US Secretary of Navy, 1973-05-01
3797394 Chaff dispenser, method of dispersing chaff, J Thurston, G Adams, 1974-03-19
3910189 Deployment of conductors into the atmosphere, Roger W Whidden, Frank R Leonard, Sidney Rosenthal, Richard O Fitzpatrick, USAF, 1975-10-07, 102/351; 102/377; 342/12; 102/504 -
3965472 Off-resonant chaff system for a large target viewed by low frequency radar, James Nickolas Constant, 1976-06-22, -
4063485 Decoy launcher system, Huges, GD, 1977-12-20, - anti ship multiple launcher
4404912 Chaff cartridge for aircraft defense, Paul Sindermann, Diehl Stiftung and Co, 1983-09-20
4167009 Re-entry chaff, Walter Schwartz, McDonnell Douglas Corp, 1979-09-04 - long range ballistic missile

4171669 Decoy
                  flare, Navy, 1979-10-23

4171669 Decoy flare, Navy, 1979-10-23, 102/357; 102/342; 102/350 - "A decoy flare cartridge for use in an aircraft photoflash cartridge rack", electrical ignition,

"The expelled hydrocarbon compounds are then ignited to form an infrared source for decoying a hostile infrared seeking missile away from the tailpipe of the decoy-carrying aircraft."

Aerial cameras like the KA-45, KA-56, KS-87 (National Museum) can be used at night when a Photoflash cartridge is used to make a flash.  The M-112 (1 pound) or M-123 (4.3 piound) were common.  The LA-307A Ejector, NSN: 6760-00-015-1927 holds 10 of the M123 cartridges.  They appear to be much larger than today's flare/chaff cartridges.

Installation and Maintenance of Aerial Photographic Equipment, AF 95-3, 1964 (pdf) 449 pages - pg252:
Two types of cartridges are available. These are the M-112 and the M–123. The M-112 is ejected from the A-5 (50 cartridges) or A–6 (52 cartridges) cartridge ejector while the M–123 is ejected from the B-4 ejector (20 cartridges) [LA-307 holds 10 cartridges]. Selection of either cartridge is made by actuation of the MODE switch on the sensor control panel to NIGHT A or NIGHT B. The previous action will also switch the cameras and the photographic control unit to the night mode. The photographic control unit then routes the shutter trip pulses to the cartridge ejectors in the flare pod. The pulses are also used to operate the cartridge remaining counter and the count limit counter on the film cartridge exposure panel. When a predetermined number of cartridges has been expended, the cameras will automatically shut down. The clam-shell doors on the flare pod open and close automatically when the select buttons on the sensor control panel are actuated. The door position is monitored by a door-closed warning light on the door position indicator panel. For emergency opening, the EMERG OPEN switch on the same panel is actuated to apply pneu matic pressure to the door mechanism. Provision has also been made on this aircraft so that the entire flare pod can be jettisoned in case of an emergency.

Table 7-2 Characteristics of the M-112 and M-123A1 Cartridges

Total Weight
16.4 oz
4.3 lbs
Outer case weight
4.4 oz
1.3 lbs
Flash powder weight
7 oz
1.7 lbs
Muzzle velocity
130 f/s
70 f/s
Peak candlepower
110 million
265 million
1.2 million
6 million
Time to peak
3 mS
4 mS
Duration of flash
30 mS
40 mS
Fuze delay available and A/C used: RB-47E, RB-57A, RB-66, RF-84F

Some of the early nighttime aerial photography was done using strobe lights the high energy drive was used for the Fat Man atomic bomb.  See my web pages: Egerton, GR Strobotac, Sonar & Krytron
Also see: 
Harold "Doc" Edgerton - Nighttime Photography -
Wiki: Photoflash bomb -

Aerial photographic reconnaissance, AF 55-6, 1955, (pdf), 153 pages -
                            photographic reconnaissance, AF 55-6, 1955
Electrically triggered primer, not like small arms with firing pin.
The M-112 and/or T-89 photoflash cartridges look like precursors
to the modern round flare/chaff cartridges.

Evaluation of the XM-143 Photoflash Cartridge (DTIC_ADA030773), May 1951 - plastic: 1.48" dia x 6.20" long, Aluminum: 1.57" dia x 7.81" long.  Evaluated on the L20 blimp (Wiki) and AO-1 Fokker (Wiki).

Patent Citations (11)
Publication   numberPriority date  Publication date  Assignee  Title
US3150848A *  1961-06-28  1964-09-29  Samuel E Lager  Method of decoying a missile from its intended target - pufs of IR radiation from burning
US3243270A *  1960-06-01  1966-03-29  Continental Oil Co  Preparation of gelled liquids
US3439612A *  1966-11-14  1969-04-22  United Aircraft Corp  Hybrid flare -  hybrid rocket motors as the source of radiant energy
US3473472A *  1964-08-13  1969-10-21Us Navy  Photoflash cartridge
US3612857A *  1970-03-16  1971-10-12  Dave P Beatty  Location marker for producing luminous display
US3712224A *  1971-06-21  1973-01-23  Us Navy  Decoy flare with traveling ignition charge
US3736874A *  1970-05-28  1973-06-05  Us Navy  Chemiluminescent expulsion device
US3808940A *  1964-12-24  1974-05-07  Gen Dynamics Corp  Portable decoy launcher system and rounds therefor
US3841219A *  1964-08-12  1974-10-15  Gen Dynamics Corp  Decoy rounds for counter measures system
US3964393A *  1974-06-21  1976-06-22  The United States Of America As   Represented By The Secretary Of The NavyIgniter
DE2509539A1 *  1975-03-05  1976-12-23  Dynamit Nobel Ag  Single or multiple component ejector for artificial cloud - has generating materials ejected by compression for mixing to form cloud after ejection

Cited By (17)
Publication number  Priority date  Publication date  Assignee  Title
US4292208A *  1974-05-03  1981-09-29  Alloy Surfaces Company, Inc.  Diffusion coating combinations
US4349612A *  1978-11-24  1982-09-14  Alloy Surfaces Company, Inc.  Metal web
US4444111A *  1978-09-30  1984-04-24  Nico-Pyrotechnik Hanns-Juergen Diederichs Kg  Crowd control projectile and method of ejecting same
US4498392A *  1981-06-03  1985-02-12  Etienne Lacroix - Tous Artifices  Infrared decoy launching device to be deployed rapidly with a double safety device
US4646643A *  1984-08-03  1987-03-03  Proll Molding Co., Inc.  Cartridge assembly for a projectable load
US5092244A *  1984-07-11  1992-03-03  American Cyanamid Company  Radar- and infrared-detectable structural simulation decoy
US5129323A *  1991-05-24  1992-07-14  American Cyanamid Company  Radar-and infrared detectable structural simulation decoy
US5343794A *  1979-04-04  1994-09-06  The United States Of America As Represented By   The Secretary Of The NavyInfrared decoy method using polydimethylsiloxane fuel
US5565645A *  1995-04-24  1996-10-15  Thiokol Corporation  High-intensity infrared decoy flare
US5602362A *  1981-12-11   1997-02-11  Lacroix Soc E  Electromagnetic decoy with delayed ejection
US5619009A *  1995-01-31  1997-04-08  Princhim S.A.  Smoke bomb case
US6324955B1  1992-04-20  2001-12-04  Raytheon Company  Explosive countermeasure device
US20040011235A1 *  2000-12-13  2004-01-22  Callaway James Dominic  Infra-red emitting decoy flare
US6686866B1  2002-09-26  2004-02-03  The United States Of America As Represented By The Secretary Of The Navy  Two-piece radar-absorbing end cap assembly
US20050029394A1 *  2003-07-22  2005-02-10  Ackleson James E.  Conformal airliner defense (CAD) system
US7343861B1  2005-05-31  2008-03-18  The United States Of America As Represented By The Secretary Of The Navy  Device and method for producing an infrared emission at a given wavelength
US10001351B2 *  2014-03-03  2018-06-19  Etienne Lacroix Tous Artifices S.A.  Decoy cartridge for aircraft

4313379 Voltage-coded multiple payload cartridge, David W. Wallace, Tracor Aerospace Inc, 1982-02-02, 102/217 - uses Zener diode to allow polarity control of expendables
4371874 Chaff dipole elements and method of packaging, Richard L. Bloom, App: 1973-10-05, Pub: (10 Year Delay) 1983-02-01, 342/12 - use Al, Cu, Zn & Tin to get different fall rates
4597332 Chaff dispenser for atmospheric re-entry, Leonard M. Hoffman, John B. Kimball, App: 1964-12-03, (22 Year Delay)Pub: 1986-07-01, 102/505; 102/351 - for missile reentry
4646643 Cartridge assembly for a projectable load, Joseph M. Goldenberg, Proll Molding Co, 1987-03-03, - "Unitary cartridge of plastic material for discharging a pyrotechnic mixture, smoke flare, chaff round, and the like is disclosed."  Works with a "replaceable impulse cartridge".

4650092 Device for the ejection of boxes through the exit of a container and box adapted for use in such a device, Nils A. T. , Andersson, Bo S. Lindgren, U.S. Phillips Corp, 1987-03-17, 221/222; 221/226; 221/231; 414/797.7 - non jamming version of 2954948box dispenser. 
4763127 Fiber under foil chaff coil, Bradley T. Sallee, Armtec Countermeasures Co, Tracor Aerospace, 1988-08-09
6231002 System and method for defending a vehicle, Boeing Co, (Rockwell), 2001-05-15 - to protect the B-1 from missile attack using a hard body (“Killer Volleyball” or “KV”) that's powered by multiple rockets. - overview of prior art systems to protect aircraft from surface launched missiles.
6980152 Externally cued aircraft warning and defense, Textron Sys,
7363861 Pyrotechnic systems and associated methods, Neal W. Brune, Andrew R. Dawson, George H. Wessels, Kevin M. Ford, Armtec Defense Products Co, 2008-04-29, 102/342; 102/336; 102/341 -
7814820 Method and apparatus for manufacturing wad-less ammunition, Jay Menefee, Polywad Inc, 2010-10-19 - related to launching systems.
8612179 Systems and methods for operational verification of a missile approach warning system, DRS Sustainment Sys, 2013-12-17, source: 345 nm UV + IR laser- for triggering AAR-47 and AAR-57 MAWS.
20030137442 Anti-radar space-filling and/or multilevel chaff dispersers, Carles Baliarda, 2005-04-05, - uses fractal patterns

Radar Man: Ed Lovick (Wiki: A12)

2599944 Absorbent body for electromagnetic waves, Winfield W Salisbury, Navy, Filed : 1943-05-11, Pub: 1952-06-10 - book (Aircraft Ref 9) mentions Aquadag (Wiki)
also see Aircraft Ref 9 & Ref 13 
While learning about the U2 got the book: "Spyplane: The U-2 History Declassified", Norman Polmar, 2001 - and the prior owner was Ed Lovick who had added newspaper clippings and post-it notes related to stealth.
Amazon: Radar Man: A Personal History of Stealth 2010 by Ed Lovick.

Radar Cross-Section

RCS (Wiki) is a measure of how much energy comes back to a radar from some object at some frequency and involves polar diagrams in azimuth and elevation.
1960 Powers shot down by the SA-2 (Wiki).
Hewlett Packard introduced the 8410 Vector Network Analyzer in 1967.  So I studied AN77-1 also in 1967 and later AN95 on Scattering Parameters.
There was a government service that would allow me, at work, to search for white papers on various topics and so I searched for "Scattering Parameters".
What came back were a large number of papers on Radar Cross Section, but none about microwave testing.

In Russia during the cold war Petr Ufimtsev (Wiki) wrote a paper "Method of Edge Waves in the Physical Theory of Diffraction".  An English version is available online as AD733203.pdf, 7 Sep 1971.  Some important concepts are Geometrical Optics (Wiki, refraction, refraction, light is a ray, &Etc), Physical Optics (Wiki, light is a wave, Wiki: Dffraction).  The paper is all about diffraction and ways to calculate it.  This formed the basis of designing aircraft (and later ships &Etc) that have very low RCS. from Aircraft Ref 9
YouTube: The Evolution Of Stealth Technology -
Also see my Aircraft web page.


Steve Blank - Secret History -list of reference books and web pages
The Story Behind the Secret History Part II. Getting B-52s through the Soviet Air Defense System
B-52: ALR-20, ALR-117

IMINT & Analysis- includes SAM sites

First In, Last Out: Stories by The Wild Weasels - The Society Of Wild Weasels (Book & Movie)
Threat Warning for Tactical Aircraft: A Technical History of the Evolution from Analog to Digital Systems - Bjorn M. Fjallstam
The Cold War and American Science: The Military-Industrial-Academic Complex at MIT and Stanford - Stuart W. Leslie
Red SAM: The SA-2 Guideline Anti-Aircraft Missile (New Vanguard) - Steven Zaloga

National Intelligence Estimate, Number 11-3-17 Soviet Strategic Air and Missile Defenses 9 Nov 1967
Russian SAMs and ABMs
Patterns and Predictability: The Soviet Evaluation of Operation Linebacker II by Dana Drenkowski & Lester W. Grau -
Shrike Air to Ground Missiles (AGM) are mentioned.
"Operation Iraqi Freedom where precision strikes destroyed key targets but left so little collateral damage that “shock and awe” did neither."
The Hunter Killers: The Extraordinary Story of the First Wild Weasels, the Band of Maverick Aviators who Flew the Most Dangerous Missions of the Vietnam War, Dan Hampton,2015
War in the Forth Dimension; US Electronic Warfare, from the Vietnam War to the Present, Dr. Alfred Price, 2001 - Contains a lot of information that I did not know.  But mentions the RWR items on this web page.  "If the Fan Song ceased transmitting at that point the Shrike was deprived of homing signals and "went stupid".  While this is correct the problem was the bang-bang control system where the control fins (mounted at the center of mass) would be either translating the missile left or right and up or down.  When the target signal stopped the fins did not return to the no movement position, but instead stayed where the last command put them, so it really was "stupid".
National Electronics Museum - Library & Archives - exhibit relating to chaff, but nothing on line.
Flying Colors by Sarah Moore, 2015 - see YouTube: BookTrib Interview With Sarah Moore, Author of 'Flying Colors' - a biography of Victor Tatelman


Panoramic (Radio Corp or Labs)

1917268 Multiple frequency receiving system, Carlos B Mirick, National Electric, App: 1930-04-11, 455/145; 342/443; 455/157.2; 324/76.41; 346/33B - motorized tuning

This is the start of panoramic receivers, pan adapters and spectrum analyzers .

Navy RBY-1
                  Spectrum Scope over Hallicrafters SX-28 receiver
(Wiki: Radio Spectrum Scope source for image at left).
Navy RBY-1 Spectrum Scope over
Hallicrafters SX-28  receiver (Wiki)

2273914 Radio navigation system, Wallace Marcel, Panoramic Radio Corp, 1942-02-24, 342/462; 310/350; 310/318; 361/298.1  -
2279151 Panoramic radio receiving system, Wallace Marcel, Panoramic Radio Corp, April 7, 1042, 342/455; 346/37; 334/20; 334/33; 455/148 - tubes, motors, CRT - the beginning of spectrum analysis. Cited by 29 patents -
2312203 Radio beacon and panoramic reception system, Wallace Marcel, Panoramic Labs, 1943-02-23, 342/414; 343/726; 455/145; 327/113; 327/131  - aircraft DF, tubes, CRT
2378604 Radio altimeter and panoramic reception system, Wallace Marcel, Panoramic Labs,App: 1940-09-21, (SECRET during W.W.II) Pub: 1945-06-19, 342/462; 346/37; 334/5; 334/80; 340/977; 342/455; 455/73; 455/145 - Radio beacons where Tx frequency is coded as the altitude of the Beacon Tx.
2381940 Method and apparatus for simultaneous aural and panoramic radio reception, Wallace Marcel, Horace G Miller, Panoramic Labs, App: 1941-07-17 (SECRET during W.W. II), Pub: 1945-08-14, 455/146; 346/37; 89/41.07; 455/200.1; 455/195.1 - Wobulator (Wiki mechanical vibrator to change capacitance (frequency). Fig 8 "synchronous vibrating condenser"
2465500 Multiband fixed frequency calibration panoramic radio receiver, Wallace Marcel, Horace G Miller, Panoramic Radio Corp, Priority: 1941-07-17 (SECRET during W.W.II), Pub: 1949-03-29, 455/146; 455/147; 324/76.26 -
2498954 Panoramic receiver with means for modifying signal pulses applied to indicators, Joseph I Heller,
Panoramic Radio Corp, 1950-02-28, 455/147 -


2150553 Multiwave band superheterodyne receiver, Winfield R Koch, RCA, 1939-03-14, 455/191.1; 334/59 -
Band switch changes IF center freq along with RF input band
550 - 1500
1500 - 4500
4500 - 13500

2513384 Aperiodic radio receiver, Hoffert William J, Veatch James P, FCC Radio Intelligence Division (RID), Feb 14, 1947, 375/339 - since no wide band (500 kHz - 80 MHz) RF amplifiers existed then they used an RF detector on the input followed by audio amplification. - This is in reality a crystal video receiver since the input tube is acting as a "grid leak detector" (Wiki).  This circuit both rectifies the incoming RF and amplifies the detected audio/video signal.
1464322 Radio receiving method and apparatus - tuned
1593837 Radio signaling system - tuned RF amp then detector
1615636 Signaling system - infrasound made so it can be heard with LO (see PSR-1)
2127525 Radio receiving system - superheterodyne radio
2383126 Spaced wave keying - teletype mark and space signals each has it's own channel
2400133 Double modulation radio receiver - VHF receiver suitable for CW
2522551 Radar warning system, Williams Everard M, Oct 26, 1945, Sep 19, 1950, 342/20, 327/37, 327/20
                A method to make it easier to differentiate high pulse repetition rate signals (tracking radar) from slower rate search radar signals using vacuum tubes.
2586894 Radio receiver, Everard M Williams, Jr  Benjamin R Gardner, Sec of War, App: 1944-10-05 (SECRET?), Pub: 1952-02-26,
455/132; 455/145; 250/214R; 455/146 - "combination of a broad-band panoramic receiver used in combination with a narrow-band receiver that comprises both an oral or listening unit and a panoramic unit which are used together for analyzing signals."

2602883 Early warning detector, Edgar Koontz Clarence, Page Irving H, (Sec of the Army), Nov 17, 1942, Jul 8, 1952,
, 324/76.39, 375/224, 342/20, 327/20
                A variable inductor is in the input circuit that includes a RADAR antenna and is followed by a number of vacuum tubes.
                By calibrating in input tuning dial the input frequency can be determined and by means of the audio tone the pulse repetition rate.
                Can detect CW signals by using a switch in front of the crystal video detector (the method used in Fuzz Busters).
2642534 Multiple standard inversion frequency measuring system, Alfred K Robinson, William J Hoffert, 1953-06-16,
324/76.41 - to accuratly measure frequency of VHF signals (same inventor as Aperiodic receiver, see 2513384 above)
3465253 Pulsed and continuous wave electromagnetic signal detectors, Rittenbach Otto E (US Army), Feb 9, 1967, Sep 2, 1969,
                455/281, 342/20, 342/203, 455/337
                Two paths one for pulsed and one for CW signals.
3061795 Flip-flop varies frequency of blocking oscillator
3094663 Microwave signal checker for continuous wave radiations, Siegel Vernon H, Radatron Res & Dev Corp, Aug 3, 1962, Jun 18, 1963,
455/324, 455/226.1, 375/338, 455/130, 342/20, 343/767, 330/10, 455/347, 455/325
                Handheld device to detect CW radars like used for door openers and traffic lights.  (also see: RF-204)

3408574 Portable radar warning receiver, Oliver G Currlin, Charles J Schmidt (Maxson Electronics Corp), Oct 29, 1968, 343/703, 324/95, 342/20
                battery powered flashlight sized housing, log amp, uses what may be X-band waveguide
3500401 Radar detection device, Elliott Denman R, Miller Gerald O, US Navy China Lake, Jul 15, 1968, Mar 10, 1970, 342/20, 375/339 - APR-25?
A crystal video receiver feeds video pulses to a blocking monostable multivibrator with a 200 micro second recovery time so that the highest output frequency is 5,000 Hz.  In front of the detector is a shutter which when closed protects the detector from being burned out by a close by radar (like on an aircraft carrier when another fighter plane pilot turns on his RADAR even though he is not supposed to do that).  This is the case that triggered my development of the limiter-detector.
3550008 Radio frequency carrier wave signal detector, James A Bright, Dec 22, 1970, 375/339, 455/351, 342/20, 455/334, D10/104.1
                X-Band police radar detector using 1N23 diode and solid state circuit.

3671964 Automatic radar detection device, Trochanowski Andrew J, Wicks Steven A (US Navy China Lake), Jun 20, 1972, 342/20
                Shipboard RWR for fast PRF (tracking radar).

3765336 Chaff bullet, Kulsik R, Us Navy, Oct 16, 1973, 102/505, 342/12 - many referring patents
4176468 Cockpit display simulator for electronic countermeasure training, William B. Marty, Jr. , CUBIC Corp, 1979-12-04

Portable radar-detecting receiver, Allan B. Hitterdal, Northrop Corporation, Jan 1, 1980, 342/20, 343/774 -
                wave guide input to crystal video receiver acts as a 9 GHz high pass filter

Cavity Backed Spiral Antennas

The lowest frequency occurs when the outside diameter of the spiral is a wavelength.

Vought Aeronautics Antenna Cavity Backed Spiral 218-27510-1 01-54-05080 #CCL362

This was sold at a very low price as "not working".  You can see black burn marks on it, so probably totally smoked or it's just silver oxide?

Manufactured for
Vought Aeronautics Division
Electronic Resources Inc. L.A. Calif
Antenna, Cavity Backed Spiral
Part No. 218-27510-1.  Type No. 01-54-05080
N00383-69-A-4201???S  Ser. No. CCL362

Max working antenna diameter: 2.25" = 57.15mm
half wave = circumference = PI * D = 179.5 mm
Full wavelength: 2 * Half = 359 mm
300m / 359 mm = 0.84 GHz
The upper frequency may be limited by the Type-N connector at 12 GHz.
A 14:1 bandwidth.

Fig 1
                    Aeronautics Antenna Cavity Backed Spiral 218-27510-1
Fig 2
                    Aeronautics Antenna Cavity Backed Spiral 218-27510-1
Fig 3
                    Aeronautics Antenna Cavity Backed Spiral 218-27510-1

AEL Model: ASO111AA Cavity Backed Spiral Antenna

When this came I was surprised by how small it was, hence the photos on a 10 Dollar bill.

Fig 1
AEL Model:
                  ASO111AA Cavity Backed Spiral Antenna
1-5/8" max spiral diameter. = 41.25mm
half wave = circumference = PI * D =129.6 mm
full wavelength = 259.2 mm
300 meters / 259.2 mm = 1.16 Ghz.

The upper frequency limit may be limited by the SMA
connector to 18 GHz.

A 15.5:1 bandwidth.
Fig 2
AEL Model:
                  ASO111AA Cavity Backed Spiral Antenna

2863145 Spiral slot
                  antenna, Edwin M Turner, Air Force, 1958-12-02

2863145 Spiral slot antenna, Edwin M Turner, Air Force, 1958-12-02, 343/767; 343/895; 343/732; 343/908 -
30 MHz to 15 GHz, Flush mounting for high speed aircraft. 
3131394 Spiral
                  antenna with spiral reflecting cavity, Myron S
                  Wheeler, Navy, App: 1962-01-22

3131394 Spiral antenna with spiral reflecting cavity, Myron S Wheeler, Navy, App: 1962-01-22, 343/895; 343/914 -
3381371 Method of
                  constructing lightweight antenna, Earl D Russell,
                  Lockheed Sanders, App: 1965-09-27

3381371 Method of constructing lightweight antenna, Earl D Russell, Lockheed Sanders, App: 1965-09-27, 29/600; 264/46.6; 264/272.11; 343/912; 427/125; 29/846; 264/46.9; 343/895; 427/58 -
3717877 Cavity
                  backed spiral antenna, A Hanninen, S Scanlon, Lockheed
                  Sanders, App: 1970-02-27

3717877 Cavity backed spiral antenna, A Hanninen, S Scanlon, Lockheed Sanders, App: 1970-02-27, 343/872; 343/895 -


Information Friend or Foe (Wiki: IFF). In war time the IFF sets are programmed so that they only transmit when a secret code is received so that they do not become beacons telling the enemy where they are.  An exception happened during the Cuban Missile Crisis and Vietnam, see: Lockheed EC-121 Warning Star - College Eye - QRC-248 IFF systems that worked with Russian IFF equipment (Ref 2)

This receive then transmit system uses a local oscillator that is offset 30 Mhz from the Tx and Rx frequencies which are 60 MHz apart.  This is done in the same frequency pair used for aircraft transponders (Wiki).  Uplink to aircraft is 1030 MHz and downlink from aircraft is 1090 MHz with the LO at 1060 MHz.  

The Aeronautical Radio Navigation Service (ARNS) operates in the 960 - 1215 Mhz band.  In the U.S. the FAA manages the 960 - 1164 MHz portion of that band.  ADS-B (Wiki) operates these same two frequencies but there's an optional aircraft output at 978 Mhz available for general aviation aircraft flying in the U.S.  Plane tracking web sites, like FlightRadar24 make use of ADS-B signals.  They do this by placing a hardware box that contains a 1090 downlink receiver and a GPS receiver both connected to the internet and the headquarters facility in Germany that feeds to web service.

3945006 Radio frequency coding system, Claud E. Cleeton, Navy, App: 1952-04-04, SECRET, Pub: 1976-03-16, 342/45 - Claud worked on other IFF stuff.


I have a radar CRT which may be for the APG-40 RADAR that was used on the F-94C Starfire jet (Wiki).
This is just a place holder if I can find it.
It's maybe a 4" long persistence (yellow) CRT mounted in a black crinkle finished tube maybe a foot and a half long.  A woven metal shield dovers the cable that's maybe a couple of feet long with a large multi pin connector.


Wings Over Vietnam - Wild Weasels Documentary (46:47) -
"First In - Last Out" relates to the relative speed of the F-100 and F-105.
The function of the Shrike missile was to destroy the SA-2 RADAR antenna.  The sight could be destroyed using cluster bombs.
May 1968 - Introduction of AGM-78 Standard anti-radiation Missile
Wings Over Vietnam - Spookies, Spectres and Shadows Documentary - Gun Ships
Wings Over Vietnam - The Mission The (helicopter) Gunships -


AFCEA -Armed Forces Communication and Electronics Association
APR-25-  F100 nose antenna - another shot of nose antenna
Association of Old Crows - was a member for a couple of dozen years
Boeing - Wild Weasel - F-4 Phantom
Desert Storm - The Electronic Battle - Part 2 - Part 3 - many of the systems were Vietnam vintage
Society of Wild Weasels -
Republic F-105G Thunderchief -
Necessity is the mother of invention, and the need to counter North Vietnam's SAMs brought forth the Wild Weasel. by John D. Cugini
Air Force - F-4G Wild Weasel -
Association of Old Crows - Gold Crows (SF, CA) - Operation Desert Storm: EW Lessons Learned -
McDonnell Douglas F-4G Wild Weasel -
F110F Wild Weasel - scale model ALR-25
FAS - F-4 Phantom II, F-4G Advanced Wild Weasel -
Air Force Association - Wild, Wild Weasel - Foal Eagle '97: Wild Weasels bring 'hurt to the bad guys'  -
Air Power Over Vietnam - North Vietnam's Air Defenses -
McDonnell EF-4C Phantom II -
AWST - Kosovo Signals EW Weaknesses -
WCS Info - Weapons Control Systems
Aircraft Survivability Newsletter -
Litton Amecom - Electronic Combat - The Applied Technology Inc. was bought by Litton and is now the Applied Technology division in San Jose
Designations Of U.S. Military Electronic And Communications Equipment - AN/ALR - Airborne Countermeasures Receivers by Andreas Parsch
Fi-103/V-1 "Buzz Bomb" During WWII electronic counter measures were used to reduce the damage caused by the V-1
[7.0] Anti-Radar Missiles by Greg Gobel
Historical Electronics Museum - some AOC type exhibits
Shipboard Radio Room 4 - an RWR system fitted on a ship AN/UPD 501 Radar D/F Receiver
F-4G Desert Storm - SSgt John Burke (front seat), SSgt Fran?? (rear seat) *** tail: WW 273, WW 231, WW 303, WW 265

Air Force and Navy Radar Warning Receiver Programs - Merging Navy ALR-67 and AF ALR-69 into joint ALR-74 did not work.
T-NSIAD-87-31: Published: Apr 28, 1987. Publicly Released: Apr 28, 1987.

Pasternack Radar Demonstration Kit - probably based on the MIT: Build a Small Radar System Capable of Sensing Range, Doppler, and Synthetic Aperture Radar Imaging
DEFCON 19: Build your own Radar - The same RADAR as the above link.

A History of U.S. Navy Periscope Detection Radar: Sensor Design and Development, Shannon, Moser, Rite-Solutions, N00178-04-D-4115, 31 Dec 2014. - info on German u-boat RWR equipment development in light of the changing frequencies of British surface search radars.
Robert Morris Page (Wiki; Patents) - Over The Horizon RADAR (Wiki) - Monopulse RADAR (Wiki) 2929056 - IFF (Wiki; patent No.:254109233119123296615)
SR-71 Pilot Interview Richard Graham Veteran Tales - started out in Wild Weasel (Wiki) - also SR-71 cockpit & engine

The Navigator (801 pages) Vol 7 No. 1 January 1961 "The Wizzard" pg 2 by Capt. William C. Luce, Capt. Robert B. Stewart, Keesler T.T.C Air Training Command -  the first 43 pages are all EW related.

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Page created 6 Jan 2001.