Sonobuoy Based Outdoor Intrusion Detectors

Brooke Clarke 2011 - 2015

ID-1721 Indicator WANTED TO BUY

During the Vietnam era the "electronic battlefield" (book: Military Communications: A Test for Technology) was developed and it included various outdoor intrusion alarms (my name for these devices). Some, like the PSR-1 Seismic Intrusion Detector, used wire between the sensors and the main unit and others used a radio transmitter in the sensor and the main unit was a radio receiver.

The frequency spectrum has allocations for different users (see Frequency Allocations). One band is used by aircraft for communication and navigation (108 to 136 MHz). A number of Vietnam era outdoor intrusion sensors used this band.

Another band is used for sonobuoy operations by the Navy (162.25 to 173.50 MHz with 31 channels with 375 kHz spacing). This page is about these outdoor intrusion sensors.

Department of Defense Training Film MF11-5514
Bugging the Battlefield pt1-2 1969 Defense Department Electronic Eavesdropping Vietnam War
Bugging the Battlefield pt2-2 1969 Defense Department Electronic Eavesdropping Vietnam War

Submarines & the Noises they Make

The early work on SOund Navigation And Ranging (Wiki: SONAR), which was named after RAdio Navigation And Ranging (Wiki: RADAR), was done utilizing audio frequencies were an operator would listen on headphones (for those systems that used stereo) or a loudspeaker. The first sonobuoys also used audio with a human operator listening to the sound. This is called passive SONAR (code name Jezebel). There are no pings and whoever is doing the listening is not giving away their presence or position. When it works it's the preferred method and is by far the most common. In the 1950s the SOund SUrveillance System (Wiki: SOSUS, my page) which makes use of LOw Frequency Analysis and Recording (LOFAR) rather than the use of human audible sound was put into service. This worked on snorkeling diesel electric subs (Wiki) and on nuclear powered subs like the Soviet Hotel (Wiki), Echo (Wiki) & November (Wiki) class subs (HEN).

Active SONAR comes in two flavors, the most commonly known is the active ping like in any movie involving submarines. A ping is sent out and the time measured until it returns. The early pings were audible to humans, later ultrasonic pings were used and later still the frequency of the ping changed it into a chirp. If the propagation speed is known the distance to the target can be calculated and with the later types the radial speed of the target can be determined. The less well known active SONAR method (code name Julie) involves setting off an explosion of a couple of pounds of TNT using either the Mk-15 (Mod-12) or Mk-61 Signal Underwater Sound (SUS). The explosion generates a spike in the underwater pressure which is similar to a ping at all possible frequencies, it's the most useful type of ping, but can only be used occasionally because it requires a small bomb for each pulse.

Modern diesel electric subs are very quiet when running on battery power underwater. The explosive type active SONAR is good at detecting these subs.

The word sono-buoy is based on sound and a floating object.

Sonobuoys (Wiki) have been around since about May 1941 when P. M. S. Blackett, head of the British Admiralty committee for antisubmarine measures, proposed the idea. In June 1942, the AN/CRT-1 became the first operational sonobuoy, and on July 25, 1942, the first successful launch of a sonobuoy from an aircraft was made from a U.S. Army B-18 bomber (Wiki). (from: Not Ready for Retirement: The Sonobuoy Approaches Age 65 by Holler, Roger, Horbach, Arthur, McEachern, James).

They are nomenclatured SSQ-nn. They are a part of anti-submarine warfare (Wiki).

"All sonobuoys currently in inventory are normally launched from standard A-size tubes via pneumatic, free fall, or a Cartridge Actuated Device (CAD). Shipboard personnel may also launch them by hand or Over the Side (OTS). All are powered by either salt water activated magnesium or silver chloride, lithium chemistry, or thermal batteries and are designed to scuttle at some point after usable or selected life expires." from Approved Navy Training System Plan, for the Consolidated Sonobuoys. N88-NTSP-A-50-8910B/A SEPTEMBER 1998

CNU-239/E Shipping Tube

This may be the standard shipping container for A size sonobuoys. It's 45" long and an octagon 6-3/4" across the flats. One end unscrews and when shipping the cap is tapped to the main body. The weight depends on what model in inside.

Transport Canada SU 0850 makes provision for shipping experimental sonobuoys in this container.
But there are limitations:

(a) all the dangerous goods are contained within the aluminum body of the experimental sonobuoy described by drawings no. 200896, 200898, 200702, 200671, 200836 and 200837 deposited by Ultra Electronics Maritime Systems, a division of Ultra Electronics Canada Defense Inc. on Transport Canada's Transport Dangerous Goods Directorate file A 4069-0850;

(b) the sonobuoy contains a single UN0454 Igniter having a net explosive quantity equal to or less than 0.15 g;

(c) the sonobuoy contains a maximum of 2 cylinders of UN1013, Carbon dioxide, each having a capacity equal to or less than 0.120 L;

(d) the sonobuoy contains a quantity equal to or less than 40 "C" size lithium batteries that meet the requirement of paragraph (1) of Special Provision 34 of Schedule 2 of the Transportation of Dangerous Goods Regulations;

(e) the sonobuoy is packaged in the military performance specification plastic shipping container type CNU-239/E specified in the drawing 012-159-0009-00 deposited by Ultra Electronics Maritime Systems, a division of Ultra Electronics Canada Defence Inc. on Transport Canada's Transport Dangerous Goods Directorate file A 4069-0850;

A Size

Modern sonobuoys have an outside diameter of 4-7/8" (fit 4-15/16" launch tube commonly called 5 inch) and are 1 yard long (36"). The max weight is 39 pounds.
This is a convenient size for one man to handle on a P-3 aircraft (Wiki). The larger sizes are not easy to handle. There are smaller sizes based on getting some integer number of them inside the A size outline. 3 each is called "F" and 2 each is called "G". The other sizes are pretty much not used in volume.

Hydrophone

A hydrophone (Wiki) is the common sensor for sonobuoys and is typically deployed at 20 meters (65 feet: shallow) or 120 meters ( 328 feet: deep). A sonobuoy might have 50 depth settings that can be set prior to ejecting it from an aircraft. This is important because of what's called the thermocline (Wiki) which is where the temperature of the water changes rapidly. This changes the speed of sound (Wiki). This causes the sound to change direction just as light will be bent by a change in refractive index (Wiki). And just like light there's conditions where the bending acts like a mirror and all the sound (or light) is reflected off the layer instead of just changing angles. So if the hydrophone is on the wrong side of the thermocline it may not hear a sub that's on the other side.

Bathythermograph (Wiki: BT)

This is a device that measures the water temperature as a function of depth. For example the SSQ-36 might first be dropped and the temperature profile recorded. Then the ideal depth for the hydrophone determined and programmed into the sonobuoy. Then the sonobuoys would be dropped.

The speed of sound in water depends on temperature so it slows down as the depth moves from the warm surface to deeper depths, but at some point the pressure caused by depth will cause it to speed up again.

Service Life

The service life can also be programmed prior to launch for 1, 3 or 8 hours. After that time the sonobuoy will sink to the bottom.

Radio Transmitter

A VHF vertical whip antenna is used. One feature of this type of antenna is that there's a null directly above the buoy so when an aircraft directly overflys the buoy there's a characteristic signal drop out. This allows confirming the buoy location. The 1 Watt transmitter is FM modulated and covers an audio bandwidth of 10 Hz to 20 kHz (about the same as a Hi-Fi system or entertainment FM radio). Note that there is no provision to hear the 37 kHz ping made by Cockpit Voice Recorders or Flight Data Recorders. The FAA and Navy need to coordinate this.

Sonobuoy Radio Channels

See the VHF part of the Frequency Assignment table for some common ways the spectrum is used. For example, FM broadcast band is 88 to 108 MHz, 108 to 136 MHz is reserved for aircraft communications and navigation. 136 to 174 is called the High VHF band (the common "Scanner" band), the old analog TV channel 7 was 174 to 180 MHz.

1st Generation

It appears that the first generation sonobuoys only had 16 channels spaced 0.75 kHz apart between 162.25 and 173.50. This was probably done using a single crystal in tube type electronics circuit.
Note: The eBay listing for a sonobuoy receiver "R-156/ARR-16B Sonobuoy Receiver 62-72 MCs." is in error by leaving off the "1" in front of the frequency.

2nd Generation

At some point (When?) the channel spacing was cut in half. At that time to maintain channel number comparability with the old system, the new channels were added in between the old channels as shown in the table. (chan 1) 162.25 to 173.50 with spacing of 0.375 MHz.
The R-1170 ARR-52A sonobuoy receiver has 31 crystal controlled channels.

3rd Generation

At some point (When?) the total number of channels was increased to 100 (or 99?) by adding channels starting at 136.000 MHz (chan 32) and going to 161.125 (chan 99) with the same 0.375 MHz channel spacing. Is there a channel 00?
So the band plan in frequency order is, the new lower frequency channels from 136.000 to 161.125, skipping 161.500 and 161.875 (Why?), then the 2nd generation channels from 162.250 to 173.500 MHz.

USQ-46 (USQ, below)

The USQ-46 receiver has 3000 channels with a 6.25 kHz channel spacing.
If the received frequency is below 162.000 MHz then the Freq_MHz = 145.525 + <chan#> * 0.00625,
if the frequency is equal or greater than 162.000 then Freq_MHz = 162.000 + <chan#> * 0.00625.
So there's a strong sonobuoy flavor to how the USQ-46 does channel assignment.
If you know about this, tell me.

Black Box

This is a beacon transmitter that just transmits a narrow pulse in the sonobuoy frequency range. But, the signal requires a receiver with about a 150 kHz channel bandwidth.
Since the only information it sends is it's center frequency, probably one of a small list of possible frequencies and one of two possible duty cycles the process gain is extremely high.

During the Vietnam era there were airplanes circling over areas where ground based sensors were placed to relay the VHF sensor signals to a ground station (Wiki). This page was made because of the similarity of ground based intrusion sensors and sonobuoys. They both work the same way and both have the same reception requirements.

My guess is that today there is a satellite system doing the same thing. This system would receive in the 136 to 173 MHz range and use digital IF processing, similar to what's done in the HP 4395A combined spectrum network and impedance analyzer. If that was the case then it would be straight forward to have the ability for this receiver to receive not only sonobuoy signals but also the waveform used by the Black Box.

This makes sense in that the system would have world wide coverage without the need to have planes circling 24/7 like in Igloo White.

The WiNRADiO MS-8118/WSB Sonobuoy Telemetry Multichannel Receiving System (WiNRADiO) covers 136.000-173.500 MHz (custom frequency ranges available) with an IF bandwidth of 30 kHz @ -6 dB.
They also have a WiNRADiO AX-61S Sonobuoy Telemetry Antenna that covers 135 to 175 MHz.
The G315i receiver can be ordered with an optional hardware wide band demodulator that's the same as in the sonobuoy receiver: WR-G315i Receiver Options or for the WR-G315e Receiver Options .
Note the black box beacon transmitter may be associated with the SEAL Delivery Vehicle (Wiki: SDV).
That would be perfect for receiving the Black Box signal (thanks to Chip Veres) for letting me know about the MS-8118. But this raises a new question, what else generates such a wideband signal?

The transmission frequencies of some black box units are: 164.5375 & 164.5875 MHz. Note neither of these is on channel 4 (164.50 MHz) and they differ by 50 kHz, not likely an accident.

Distributed Sensor Networks, Second Edition: Image and Sensor Signal Processing (Chapman & Hall/CRC Computer and Information Science Series)

Iyengar, S. Sitharama- book on order 14 Nov 2015 has info on Igloo White and may have some insights into the satellite system?

Chan	Freq	Chan	Freq	Chan	Freq
1	162.25	6	166.00	11	169.75
17	162.625	22	166.375	27	170.125
2	163.00	7	166.75	12	170.50
18	163.375	23	167.125	28	170.875
3	163.75	8	167.50	13	171.25
19	164.125	24	167.875	29	171.625
4	164.50	9	168.25	14	172.00
20	164.875	25	168.625	30	172.375
5	165.25	10	169.0	15	172.75
21	165.625	26	169.375	31	173.125
				16	173.50

Channel 15 (172.75 MHz) is used as an emergency search and rescue frequency.

Command Function Select (CFS)

The aircraft can transmit to the sonobuoy to change the commands while it's floating in the water which is much better than the old way of making the command decisions prior to launch.
The UHF frequencies used for this are: 282.900, 291.300, 291.400, 291.500 MHz

Directional Frequency Analysis & Recording type acoustic sensor (DIFAR)

These buoys use directional hydrophones (Wiki) covering 5 or 10 Hz to 2400 Hz combined with a magnetic bearing sensor and transmit this information.
They can be used to passively listen, to listen for reflected pings or the shock wave from a small explosion.
Whale researchers use them (Tools > DIFAR Sonobuoys).

Because the lower frequency limit is below Hi-Fi audio, consumer grade tape recorders could not be used so instrumentation type recorders were used.

With the advent of Digital Audio Tape (DAT) recorders the DIFAR signal could be recorded on a DAT tape.
The following is a frequency spectrum of the DIFAR signal with a voice channel added for use with a DAT tape recorder.
Frequency
Spectrum of the DIFAR signal with a voice channel added for
use with a DAT tape recorder

Frequency
Spectrum of the DIFAR signal with a voice channel added for
use with a DAT tape recorder

Analog circuitry, like using the LM1496 Balanced Modulator-Demodulator can be used to manipulate these signals.

Note seismic sensors (geophones) respond to frequencies below 10 Hz so there's an overlap with DIFAR and other hydrophone frequencies.

DIFAR Patents

3987404 Underwater Direction Finding System is the patent that defines how a directional (the DI in DIFAR) sonobuoy can be made.

3987404 Underwater Direction Finding System, Sanders, (filed: Nov 3 1967) Issued: Oct 19, 1976, 367/3; 367/125; 367/126 -

"An underwater direction finding system includes a pair of directional hydrophones and a compass in a novel arrangement which associates the signals from all three elements with a single subcarrier. Subsequent demodulation of the subcarrier signals in an airplane or ship then provides directional information directly referrenced to the earth's magnetic coordinates."
Calls:

US2754493	Indicator for Sound Direction Finder	Feb 4, 1955	1956	LIPPEL
US2837730	Deflection Method for CRT	Aug 4, 1952	Jun 3, 1958	IAUAEM
US2867788	Object Locating Systems (sub hunting)	Feb 27, 1943	Jan 6, 1959	HARRY
US3022462	Frequency Modulation Detector System (see below)	Jan 19, 1953	Feb 20, 1962	FREQUENCY MODULATION DETECTOR SYSTEM
US3148351	Directional Hydrophone System (see below)	Jun 12, 1961	Sep 8, 1964	FILTER
US3160850	Underwater Locating Apparatus (Glomar Explorer?)	Dec 27, 1960	Dec 8, 1964	DUDLEY
US3176262	Directional Sonar Systems (dipping SONAR)	Apr 6, 1960	Mar 30, 1965	EHRLICH ETAL, DIRECTIONAL SONAR SYSTEMS

Referenced by:


US4872146	May 23, 1988	Oct 3, 1989	Canadian Patents & Development Limited	Method and apparatus for simulating phase coherent signal reflections in media containing randomly distributed targets
US4879694	Mar 4, 1988	Nov 7, 1989	Rockwell International Corporation	Difar demultiplexer circuit
US5253223	Apr 27, 1992	Oct 12, 1993	Den Norske Stats Oljeselskap A.S.	Seismic device
US5265066	Apr 27, 1992	Nov 23, 1993	Den norske stats oljeselskap a.s	Seismic cable
US5442590	Apr 27, 1992	Aug 15, 1995	Den norske stats oljeselskap a.s	Seismic cable device
US6108270	Jul 6, 1999	Aug 22, 2000		Torpedo seeker head having directional detection independent of frequency
US6622647	Jun 26, 2001	Sep 23, 2003		Active noise cancellation for a torpedo seeker head
US8059485	Jun 4, 2008	Nov 15, 2011	NEC Corporation	Communication system, information collecting method and base station apparatus

3461421 Advanced Direction Finding Sonobuoy System, (Collins Radio), Aug 12, 1969, 367/124; 367/3; 367/6; 367/125; 367/126; 367/128

Calls:
2898589 Hemispherical Acoustic Phase Compensator, F.R. Abbott, Aug 4, 1959,
3022462 Frequency Modulation Detector System, Philco, Feb 20, 1962, - sonobuoy to aircraft

sonobuoy includes mag bearing and hydrophone.
Calls:
2476301
2631270

3148351 Directional Hydrophone System, Bartlett Labs, Sep 8, 1964, 367/125; 367/3; 367/124

Calls:
2903673
2946980
2977570
3000078
3027627
3030606

3239799 Sonar Directional Beam Focusing System, GE, Mar 8, 1966,

Referenced by:

			ignee	Title
US4078222	Nov 20, 1969	Mar 7, 1978	The United States of America as represented by the Secretary of the Navy	Direction determining apparatus
US4371957	Dec 12, 1969	Feb 1, 1983	Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence	Antisubmarine warfare system
US4604733	Jan 3, 1984	Aug 5, 1986	Westinghouse Electric Corp.	Apparatus for determining range and bearing
US4653033	Oct 4, 1984	Mar 24, 1987	Thomson-CSF	Goniotelemetry system
US4691305	Sep 5, 1985	Sep 1, 1987	The United States of America as represented by the Secretary of the Air force	Automatic attenuator for sonobuoys
US4872146	May 23, 1988	Oct 3, 1989	Canadian Patents & Development Limited	Method and apparatus for simulating phase coherent signal reflections in media containing randomly distributed targets
US4914734	Jul 21, 1989	Apr 3, 1990	The United States of America as represented by the Secretary of the Air Force	Intensity area correlation addition to terrain radiometric area correlation
US5859915	Apr 30, 1997	Jan 12, 1999	American Technology Corporation	Lighted enhanced bullhorn
US5885129	Mar 25, 1997	Mar 23, 1999	American Technology Corporation	Directable sound and light toy
US7088830	Mar 18, 2002	Aug 8, 2006	American Technology Corporation	Parametric ring emitter
US7109789	Jan 21, 2003	Sep 19, 2006	American Technology Corporation	Modulator—amplifier
US7224219	Sep 18, 2006	May 29, 2007	American Technology Corporation	Modulator-amplifier
US7564981	Oct 21, 2004	Jul 21, 2009	American Technology Corporation	Method of adjusting linear parameters of a parametric ultrasonic signal to reduce non-linearities in decoupled audio output waves and system including same

Earth's Field Magnetic Detectors

Also see my Flux Gate patents web page.

2252059 Method and a device for determining the magnitudes of magnetic fields, Gustav Barth, Priority Dec 24, 1936, Pub Aug 12, 1941 - rod fluxgate
2560132 Unbalanced magnetometer, Schmitt Otto H, Jul 10, 1951, 324/255, 340/870.33 - second harmonic
2488341 Detection system, Thaddeus Slonczewski, Bell Telephone Labor Inc, Nov 15, 1949, 324/246, 340/870.33, 324/254, 324/253 - moving parts

Calls:
2485931 Magnetic field strength indicator - no moving parts
2468968 Magnetic field strength indicator
2027393 Cathode ray device
2047609 Magnetic field direction and intensity finder
2053154 Direct-current indicator
2438964 Magnetic field detector - second harmonic magnetometer

Magnetic Anomaly Detector (MAD) Patents
2406870 Apparatus for responding to magnetic fields, Vacquier Victor V, Gulf Research Development Co, filed: Jul 21, 1941,

324/253, 102/417, 33/361, 318/647, 324/326, 324/345, 324/255, 340/870.33, 102/427
This is THE MAD patent and is referenced by a very large number of others.d

The following detectors are towed on a cable from a plane flying at 300 feet above the water:
2379447 Antisubmarine device, Lindsey Henry A D, Jul 3, 1945, 102/417, 102/212, 340/551, 324/247, 324/67, 307/652, 324/258, 340/552
2404806 Submarine detector, Lindsey Henry A D, Jul 30, 1946, 340/850, 102/402, 324/247, 324/331
2424772 System for detecting magnetic masses, Frank Rieber, Interval Instr Inc, Jul 29, 1947, 324/247, 324/331, 322/1, 324/257, 322/59, 340/870.32
2549857 Cable-suspended aerodynamic body, Schonstedt Erick O, Apr 24, 1951, 324/260, 324/262, 114/24, 244/3, 74/5.00R, 324/331, 324/246, 33/397, 33/366.11
2632884 Orienting mechanism for magnetic detector devices, Murphy Paul M, Mar 24, 1953, 324/253, 318/647, 324/246, 324/331
2696602 Compensated magnetometer, Richard Evans Chauncey, Dec 7, 1954, 324/253, 324/345 - uses term "magnetic anomalies"

Magnetic buoy

2397137 Magnetic controlling device, Glennon James B, Maltby Wilson R, Sellman Albert H, filed Jun 25, 1941, pub Mar 26, 1946, 340/850, 324/259, 340/551, 102/417
3526002 Magnebuoy, Ramond C Waddel, Filing date Mar 31, 1960, Publication dateAug 25, 1970 (maybe withheld secret), 340/852

Bathythermograph Patents

2297725 Bathythermograph, Spilhaus Athelstan F, Submarine Signal Co, Filed: Aug 10, 1938, Pub: Oct 6, 1942, 374/136, 374/E01.3, 73/729.1 - marks smoked glass slide with pressure & Temp

2515034 Bathythermograph, William M Ewing, Allyn C Vine, Us Navy, Filed: May 27, 1944, Pub: Jul 11, 1950, 374/136, 73/300 - rapid response to temp & pressure (recording inside unit)

2629083 Expendable radiosonic buoy, Barkson Joseph A, Mason Russell I, Mcnary James C, Filed: Sep 21, 1944, Pub: Feb 17, 1953, 367/3, 343/709, 455/99, 441/33, 441/23, 343/705, 343/901 -

2703009 Bathythermograph, Ewing William M, Vine Allyn C, Filed: Nov 28, 1945, Pub: Mar 1, 1955, 73/178.00R, 346/120, 73/712, 73/742, 374/E01.3, 73/299 - for use on subs

3098993 Sonobuoy-bathythermograph system, Coop Jesse J, Jul 23, 1963, 367/134, 374/E01.3, 340/870.17, 340/870.6, 367/185, 367/3, 374/E01.4, 73/170.34 - sound output that can be heard by sonobuoy.
3119090
3135943
3273393 Bathythermograph, Spark Wallace R, Douglas Aircraft Co Inc, Sep 20, 1966, 374/136, 340/852, 73/170.34, 374/E01.3, 73/292, 367/134, 374/142 -

Reserve Batteries

Reserve batteries have the electrolyte and anode separated. This allows them to be stored for more than a decade and still retain their full capacity when activated. Example applications are hearing aid batteries, artillery shells and sonobuoys, weather balloons, torpedoes.

Salt water activated magnesium

Because of the green particles that can be seen on the black plastic I suspect the chemistry is one of the following in the SSQ-53B:

Magnesium/Cuprous Chloride
Magnesium/Cuprous Iodide-Sulfer
Magnesium/CuprousThiocyanate-Sulfer

Salt water activated silver chloride

Table of Sonobuoys

Naval Consolidated Sonobuoys @FAS -

Function

Start

End

Links

AN/CRT-1

5 vacuum tubes single channel FM transmitter between 67 & 72 Mhz.
See Roswell Connection below where this was used with "disk microphones" on Project Mogul
CANADIAN LANCASTER - AN/CRT-1 SONOBUOY SYSTEM - drawing of aircraft equipment & buoy
Chapter 16 - SOFAR, HARBOR DEFENSE, AND OTHER SONAR SYSTEMS
Naval History - RADAR - MAD and CRT-1
CRT-1A: 67.7 to 71.7 MHz
CRT-1B: 62.9 to 66.9 MHz

Jun 1942

AN/CRT-4

RDRH

Feb 1943

AN/CRT-1A

6 channels

1944

AN/CRT-1B

separate web page

AN/SSQ-1

upgraded
CRT-4

not UK SSQ-20

SSQ-2

15 Feb 1955

jproc
SS-383

1950 start of: Sound Surveillance System (SOSUS)

SSQ-20

1951

SSQ-2B

Julie explosive

1956

AN/SSQ-15

Julie RO B-size

SSQ-23

Julie

1956

19 Nov 1964

SSQ-28

Jezebel-LOFAR

1960

19 Nov 1964

SSQ-36

BT
The BT sonobuoy is an expendable thermal gradient measurement sonobuoy that operates on one of three or one of 99 Radio Frequency (RF) channels. It consists of a thermistor (Wiki) temperature probe that descends through the bottom of the sonobuoy canister producing a continuous reading of temperature versus depth. The thermistor temperature probe will descend to 1000, 2000, or 2625 feet, depending upon the sonobuoy selected.

Fig 36-01 Tubes

SSQ-36,
CNU-239/E Shipping, Launching & Housing
Tubes

Ship: 7" x 45"

Launch: 5-3/8" x 39-1/4"

Housing: 4-3/4" x 35-7/8"

Fig 36-02 Launch Tube Cap - twist and lift.

Fig 36-03 Housing (what drops through air and lands in ocean

SSQ-36
Housing (with plexiglass cap in place)

SSQ-38

30day omni-directional LOFAR
(replaced SSQ-28)
10 to 6,000 Hz
31 chan

1964

1 June 1961

SSQ-41

single hydrophone

1964

SSQ-47

(replaced Julie explosive system)
active ping omni directional range only
replaced by SSQ-50

1968

SSQ-48

replacedd by SSQ-41B

26 Feb 1981

SSQ-50

CASS

SSQ-53

31 RF Channels
10 Hz - 2.4 kHz
90 feet fixed depth

Sep
1967

SSQ-53A

90 or 1000' depth
1 or 8 hours

SSQ-53B

DIFAR
fitted with microprocessor controlled EFS capabilities,
with three depth selections [100, 400 or 1000 feet],
three operating time selections of 1, 3 or 8 hours,
99 vhf channels.

Operation

Before inserting the launch tube into the aircraft chute the sonobuoy is programmed for operational life, channel number and depth by using the SET button. If done incorrectly pulling the TEST plug for a few seconds will allow reprogramming. Power for this comes from a couple of coin cell batteries. The correct programming can be confirmed by pressing and holding the VERIFY button for a couple of seconds.

When forced from the aircraft chute by means of compressed air the lid is blown off the launch tube deploying the parachute on the metal sonobuoy housing. The plastic launch tube stays in the chute.

When the metal sonobuoy (Fig 53-8) impacts the water is starts to sink and water activates the reserve battery. As soon as the battery has power (probably within a few seconds) the squib retaining the large spring allows an arm to puncture a compressed gas bottle inflating the buoy/antenna (Fig 53-17). At the same time, depending on the programmed depth one or both rods (Fig 53-21) are driven down to set the amount of cable that will unspool controlling depth of the sensor. A very short time later the three main components of the sonobuoy are separated as the metal outer housing is blown clear and sinks.

With power the radio transmitter begins to send it's signal.

The duration may be determined by a simple electric timer that shuts off the transmitter after the programmed time, or . . . there may be some provision to do more?

Although very old I believe this unit would still work.

Fig 53-1

SSQ-53B Sonobuoy in Launch Container next
to shipping tube

Launch Tube 5-3/8" diz x 39-5/8" long
dated 5/87 - it's 12/11 now so this is just under 25 years old.
The shipping container probably was left on the ground.
If you know the deployment sequence let me know what it is.

Fig 53-2
Top: Channel (01 to 99), Duration (1, 3 or 8 hrs), Depth (90, 400 or 1000) Ft., Verify

SSQ-53B
Sonobuoy Settings Channel, Duration Launch
Container

What was a transparent membrane has aged and is falling apart. When intact would
provide a moisture barrier so the decissant could keep the inside dry.

Fig 53-3

Sonobuoy Launch Container LAU/126A
NOO 83-86-C-0007
.OT 036

Fig 53-4
LAU/126A Launch Container Cap

Fig 53-5
Cap Off by removing 4 black plastic clips

SSQ-53B Sonobuoy Launch Container
LAU/126A Cap removed

It's not clear how the sonobuoy was programmed and in what order loaded into the aircraft launch chute.

Fig 53-6
Inside the Launch Tube, marked:
Caution: - Disengage before launch
Caution: Spring Loaded

SSQ-53B
Sonobuoy Launch Container LAU/126A after Cap
removed

Fig 53-7
SSQ-53B Ready to launch (string holding spring snare)
The metal SSQ-53B housing is 4-3/4" O.D.
The label just to the right of the depth scale says:
WARNING Remove Plug Prior to Test
EFS Battery may be damaged if pins 1
and 2 are shorted or voltage is
applied across pins 1 and 2.

Voltage applied to pin 3 may cause high velocity ejection of top plate.
Reinstall plug before use.

SSQ-53B Sonobuoy Ready to Launch (string
holding spring snare)

Fig 53-8 With parachute deployed

The gray plastic cap was preyed off instead of submerging in water and dissolving the two metal links?

Fig 53-9
There are three functional parts. The right is the antenna-buoy cover and receiver/transmitter,
the center is cable spools and the bottom (left) is the sensor.

Fig 53-10
Three Major Components:
Left: Radio, Antenna, Battery
Center: cable
Right: Sensor

SSQ-53B
Major Components: 10 Radio, Antenna, Battery,
2) cable, 3) Sensor

Fig 53-11
Sensor, marked:
Sparton Corporation
120-0127-002
Clock Number: 0358 Date 06/03/87
{bar code]
SIN: -67.1 db COS: -68.4 db OMNI: -72.1 db
the latter three parameters are related to the DIFAR aspect of the sensor.
The black cylinder hanging out the bottom is probably the omni hydrophone.

Note: There's a single green/white wire (cable) going to/coming from the sensor. I expect it's a small coax cable, but it remains to be seen.

Fig 53-12 Radio Buoy

SQQ-53B Sonobuoy Radio buoy top
component

Fig 53-13
With cap pulled off and buoy opened, but not inflated.
There appears to be small wire antenna with a resistor at the top.

SSQ-53B
w/buoy pulled out by not inflated

Fig 53-14 Test Socket & Memory Battery
Test Socket cap held by O-Ring, need big pliers to pull/twist it out.
There was a jumper plug in the socket, more later.

Memory Battery and PCBs
There's a big spring that can puncture what's probably a good size CO₂ cylinder in order to inflate the buoy/antenna. There's what looks like a fusible link holding the spring in tension that could trigger the gas.

Also at the bottom of the PCB chamber there are a couple of lever arms that have a resistor wrapped around their ends. If the resistor was exploded (over powered) then it would release these arms to do something (maybe control the depth through the cable spools?

The two coin cells are in the white plastic holder. They provide about 6 Volts and are still good.

On the left board there are three red wires (Battery +), a bare stub where I wiggled off the battery + wire, and a yellow wire (to socket pin 3). The bare wire at the top (just under the coin cells) that's soldered to a lug on the central metal plate is ground (same as the cast metal frame where the battery- wire connects.).
Fig 53-16

Battery

Fig 53-17 Main Battery held to cylinder with double sided foam tape.
1 lb 11 oz. 4-1/4" hi x 3-1/8" w x 2-9/16" d (11 x 8 x 6 cm)
There is a hole on two sides just under the top cover to allow water to enter.

This is a water activated reserve battery. 1986 Mfg date.
Fig 53-18
SSQ-53B Reserve water activated battery
Water Hole

In the other photos you can see green deposits on the inside of the radio/buoy black plastic. I think that's because this reserve battery contains Copper in a form that allows it to escape. This may be a limiting factor for the shelf life. The Copper deposits are probably the result of the failure of the moisture proof membrane that covers the programming push button switches. Once the moisture in the air gets to the reserve battery it's going to become a carrier for the copper and also will lower the battery capacity.

Idea: Rather than depend on the moisture proof membrane (and Desiccant (Wiki)) to keep the reserve battery fresh, it should be in a compartment that's sealed until the metal housing is separated from the launch tube..

The two coin cells are still good condition after almost 25 years since this was manufactured.

4262069 Lead chloride battery plate, John L. Devitt, Douglas E. Johnson, Robert S. Willard, Sparton Corporation, Apr 14, 1981 -
Cites:
3468710 Sea water battery, Jerome Goodman, Philip I Krasnow, Nuclear Research Associates, Sep 23, 1969 -
Cites:
2692215 Alkaline dry cell, Ruben Samuel, Oct 19, 1954 -
3005864 Sea water battery, Duncan T Sharpe, Bell Telephone Lab, Filed: Mar 29 (16 year delay), 1945, Pub: Oct 24, 1961 - maybe the Mk 18 torpedo (Wiki)

Fig 53-19 High Pressure Gas bottle to inflate buoy/antenna

SSQ-53B Sonobuoy buoy/antenna high
pressure gas inflation components

There are three PCBs:
Blue: modulator & RF exciter
Green: I/O panel
Tan: RF Power Amp

Fig 53-20 Test Socket Message
SSQ-53B Test Socket Message

Socket Pin	Ohms to Gnd	Ohms to Bat+	Plug
1	1M8	1M8	1-7
2	876k	1M4
3^Note1	>1M	0.2	3-4
4	0.2	405k	3-4
5	1M	1M
6	1M	1M
7	0.1	405k	1-7

Note 1: pin 3 is connected to one side of the squib that can cut the lanyard holding
the arm that will puncture the high pressure gas for deploying the buoy/antenna.

Pins 7 & 4 are connected to the ground bulckhead (0.0 Ohms).
Pin 3 is connected to the red battery wire (0.0 Ohms)

The jumper plug connects:
1 to 7
3 to 4

With the jumper plutg removed:
Red test lead to red battery wire (black lead to ground) = 1M00 Ohms
Black tet lead to red battery wire (red lead to ground) = 401k Ohms

Pin 1 is connected to the negative (black wire) leading from the two stacked coin cells).
The jumper plug connects pin 1 to pin 7. Pin 7 is connected to the micro controller. So these two pins relate to zeroing the programming.

If you have information on how the test socket is used please let me know.

Fig 53-32 Test Socket Schematic
See Fig 55-29 & Fig 53-31 for photo of Fuse 1 (LE 1A)
SSQ-53B Test Scoket Schematic diagram

A few of possible reasons for placing a fuse directly across the reserve battery. One or more of them might be the reason. For Now I'll just remove the fuse.
1) Shorting the main power supply protects the squibs are from being
    fired by static or electromagnetic fields (like high power transmitters on board ships).
2) The reserve battery may like activate better when heavily loaded. Note: The
   BA-4386 Magnesium battery needs to see a heavy load in order to fully activate.
3) When the fuse blows the battery is delivering at least 1 amp and that surge current
     would next go to blowing the squibs. This might be more reliable than ramping up
   the squib voltage.

Pins 5 & 6 each connect to one of the pins on the micro controller. The Test plug (cable) probably has a jumper between pins 1 & 7 to connect the EFS (coin cell) battery thus powering the micro controller, and when it's powered up the test socket pins 5 & 6 can be used. But for what? Data In/Out, firmware programming, verification check sum, something to do with the hard wired option jumper to the upper right of the LCD housing? let me know.

Fig 53-21 Buttons (now working) maybe because of cyclying the plug.
SSQ-53B EFS labels

Pressing and holding Verify for a couple of seconds will show the function settings.
To change the settings the plug must be removed for a few seconds.
Pressing SET starts the channel number counting 0 to 9 to 0.
Pressing SET fixes the tens digit and the units start counting pressing set fixes the channel number and the life bars start cycling. Pressing SET sets the life and then the depth bars start cycling, pressing SET fixes the depth. Now pressing Verify for a few seconds will display the function settings.

They were set for: 1 hr, chan 63 & 1000'
Now set for 3 hrs, chan 54 and 400'.

Fig 53-22 EFS LCD (plug shown installed)
SSQ-53B EFS LCD Verify

Fig 53-23 Depth Selection
The two levers are either in the position shown or they are pushed toward the center
to select how much cable is deployed. The selection is made by the two blue plastic
actuators using a push (or pull) of the rod with the spring. Note this rod is smooth and would not support a rotary motion. Also the two levers in the bottom of the radio compartment work in an up or down fashion, not in a rotary fashion. See Fig 53-9 and
a close up from it Fig 53-22 below..

Fig 53-24 Close up photo of depth selection blue plastic parts.

SSQ-53B depth selection blue plastic
parts

Fig 53-25 Cutting Squib Wires
Three red wires have been cut deactivating the three squibs so DC power can be applied.

SSQ-53B Cutting Squib Wires to allow
power up

Test Socket Resistance readings after cutting the wires:

Pin	Ohm to Gnd	Ohms to Bat +	Plug
1	1M9	OL	1-7
2	860K	OL
3	>1M	1.9	3-4
4	0.6	>1M	3-4
5	1M0	1M3
6	1M0	1M6
7	0.5	1.9	1-7

Gnd to Batt+ (w/0 Plug) = 1M0
Gnd to Batt+ (w Plug) = 0.7
There is still a dead short across the battery terminals!

pin3 is yellow wire to Battery + terminal (and red wires)
pin 4 is the metal frame (battery -) the black battery wire with the internal tooth lug.
This is confusing.
The hi pres gas squib is 36.2 Ohms.
One of the depth squibs is 18.5 Ohms (red to violet) not to ground.
The other depth squib is 18.3 Ohms (red to blue( not to ground.
These may be 1/8 Watt 18 Ohm resistors. Rated power would be at 1.5 Volts, 10X power at 4.7V, 100X power at 15 Volts, so if the battery is about 15 volts the resistors would fail mechanically.

Note the plug must be installed for the progrmming to work, so operation without the plug is not an option. The plug has a jumper between pins 3 and 4 that is part of the path shorting the battery + and - terminals.

The coax feeding the antenna reads 42.7 Ohms.(resistor is Yel-Org-Blk-Red

Fig 53-26 Green Cable
10K0 Ohms either polarity.
This joint is located on the black plastic bottom plate of the Transmitter section.
White to White, Green to Green.
See: Fig 53-10 and Fig 53-12.

How to take apart the transmitter? It may be possible to push everything out the bottom, but that would break the two push button switches. Probably the best way is to saw from top to bottom at two places 180 degrees apart.

Fig 53-27
The switch buttons are mechanical working through a rubber boot and can be pulled
out of the plastic housing.

After letting the top sit overnight after applying some Kroil to the joint between the plastic housing and the metal plate with 0_ring seal the assembly pressed out the
bottom easily. It was necessary to unsolder the antenna cable and the green wire to isolate the top section.

Fig 53-28 RF Amplifier
Tan PCB from top section
The antenna was connected at the top of this board where the notch is.
Gnd to the left and center to the right of the notch.
This is probably the Tx power amplifier and antenna matching/filtering board.

Fig 53-29 Command and Control Board
Green PCB from top section.
This is the digital board.
I doubt the micro controller is doing anything with the sensor data, so it's
probably running at a very slow clock frequency to conserve power.
So there's no need for a crystal for it.

There are three 2N6724 2 Watt NPN Darlington transistors just to the left of the push buttons used for firing the three squibs. The collectors go to the squibs and all three emitters are connected to the bulkhead ground plate.
Top: RF Amp board depth squib
Center: Synth board depth squib
Bottom: CO2

Maybe the transistor that blows the antenna squib is on the RF amp board?

Above the upper right corner of the black plastic LCD housing thre is a row of 6 holes and a jumper is installed in the right most of these.
What option is this selecting? Let me know.

Fig 53-30 Synthesizer and Modulator Board
Blue PCB from top section.
This board interfaces with the sensor package.
The crystal at the lower left is marked:
10.2985 MHz. This is a non standard value, see my Crystals web page.
Maybe related to the DIFAR spectrum.
This board seems to be mostly analog in nature.

On the bulkhead plate at the bottom there are the two depth programming levers.
As shown the squibs (resistors) are intact and the lever is held in the down position.
The two rods are spring loaded and trying to lift up. When the squibs are broken
the depth programming rods are forced up by their spring.

At the bottom right the green/white sensor cable can bee seen coming through a hole
and connectionto two pads.

All three squibs measure 500K Ohms to Bat+ and open to Ground. So they are not causing the dead battery short.

The data codes on the ICs are 1984, 1985 & 1987.

6 Jan 2012 - New Idea about the direct battery short.

The short may be part of a Safe And Arm system that would prevent the buoy
from becoming active prior to an actual launch. This may be a common system
used not only on sonobuoys but also things like countermeasures equipment like
flares and chaff dispensers.

If that's the case then something about the pneumatic launch would disable the short.

Fig 53-31 Fuse on digital PCB
This appears to be the cause of the dead short across the reserve battery terminals.

SSQ-53B
1 Amp Fuse Across (shorting) Reserve Battery
Terminals

Power Up (with sensor disconnected, antenna attached)
For about 15 seconds the current is in the 30 ma range then jumps up to150 to 200 ma when the transmitter turns on.
After battery power the Verify button does not work.
The battery voltage appears on the green/white cable.

On reconnecting the green cable between the floating buoy and the sensor.
Buoy
The resistance between the two wires and ground is: left: 1M and right 10k.
The resistance between the two wires and Batt+ is: left: 0.2 and right 1M
Sensor
The resistnace between either wire and the sensor metal is an open circuit.
So as of 12 Jan 2012 it's still not clear how to be sure the polarity is correct to reconnect the sensor.

Thanks to Ugo in Italy there are two conductors in the cable, one supplies power to the sensor package (which has input filter caps) and the other is the audio signal to be modulated onto the transmitter. Seawater forms a ground return between the floating transmitter and the sensor. This is confirmed by the book The Ears of Air ASW. pg 241.

1984

SSQ-53D

Dwarf "G" size version of the B

1991

SSQ-53D

DIFAR only sensor, 90, 400 or 1000 feet, no CFS
-53D(2)
5 Hz - 2.4 kHz
1/2, 1, 2, 4 or 8 hours
-53D(3)
sea state 6

2003

SSQ-53E

Digital version
Additional hydrophone @ 45' for CSO
CFS
100, 200, 400 or 1000 feet
AGC
91.44 cm long

SSQ-53F

DIFAR, CSO
made by combining the
305 cm long
SSQ-53E & SSQ-57
NSN 5845-01-475-9870
adds CO hydrophone with directional units (replaces SSQ-57)
CFS Rx - single channel UHF
Tx - 96 selectable frequencies (136 - 173.5 MHz), 1W
90, 200, 400, 1000 Ft.

2000

SSQ-57

Calibrated-LOFAR
10 to 10,000 Hz

1972

SSQ-62

DICASS
FM sweeps

1976

SSQ-62C

99 channels

1993

SSQ-62E

Command Function Select
Electronic Function Select
96 chan 136.000 - 173.500 MHz
CW Out: 6.5, 7.5, 8.5 or 9.5 kHz

Sonobuoy Tech Systems

SSQ-77A

VLAD

1981

SSQ-77B

" more hydrophones, 2 depths, 2 beams

1989

SSQ-77C

" adds RF command function selection

SSQ-86

DLC

SSQ-101

ADAR

FY97

SSQ-110

EER

30 July 1997

SSQ-125

advanced EER ADLFP sound source
used with: ADAR sonobuoys like SSQ-53F, SSQ-77C and SSQ-101

SSQ-536

SSQ-801

BARRA

SSQ-906

LOFAR Omni

SSQ-926

ALFEA, GPS

SSQ-937

SSQ-954

DIFAR

SSQ-955

HIDAR

SSQ-963D

CAMBS

Janes

SSQ-981

BARRA

ADAR: Advanced Deplorable Acoustic Receiver
ADLFP: Advanced Deplorable Low Frequency Projector
ALFEA: Active Low Frequency Electro-Acoustic
BARRA: means Listening in an indigenous Australian language - The Barra Sonobuoy System, Barra Sonobuoy Design, horizontal array
BT: Bathythermograph
CAMBS: Command Activated Multi-Beam Sonobuoy
CASS: Command Activated Sonobuoy System
CFS: Command Function Select (set function with 2-way radio when buoy is in water)
CO: Calibrated Omni type acoustic sensor (5 - 20 kHz)
CSO: Constant Shallow Omni type acoustic sensor (30 - 5000 Hz)
DICASS Directional Command Activated Sonobuoy System
DIFAR: DIrectional Frequency Analysis & Recording type acoustic sensor (5 - 2400 Hz)
EER: Extended Echo Ranging
EFS: Electronic Function Selector (RF Chan, Life, Depth, Sensor type, AGC)
HIDAR: High Dynamic Range DIFAR
LOFAR: LOw Frequency Analysis & Recording
RDRH: Rotating Directional Receiving Hydrophone
REFS: optical Remote Electronic Function Select (either while in launch tube (easy) or in water (requires laser))
RO: Range Only
SUS: Signal Underwater Sound (MK-84 MOD 1 SUS uses 3.3 and 3.5 kHz audio to generate 5 codes as messages to a sub.)
Air to sub communications.

Code	Morse	3.3 kHz	3.5 kHz	Meaning?
1	M	-	-
2	A	.	-
3	I	.	.
4	N	-	.
5		off	cont

If there are standard meanings for these let me know what they are.

VLAD: Vertical Line Array Detector

An Aircraft Control Panel for ASA-20 Julie explosive echo ranging device & AQA-1 Sonobuoy Indicator/Tracker,

	Control Drift - Compute - Reset PDI: BDHI: Marker 1 to 6, GTP: Marker 1 to 6 Insert ASA-20 or AQA-1 ASA-20 or AQA-1 A-B: 1 to 6 Computer Ellipse A: Off to 6 Data Release B: Off to 6
ASA-31 Julie Control Panel

ASA-20 Sonobuoy Recorder "Jezebel".

The AQA-5 is a 4 channel paper chart recorder.
Youtube video: AN/AQA-5 Acoustic Charts Recorder
P-3 Orion Aircraft - Walk Around -

BDHI: Bearing Distance Heading Indicator
PDI: Pulse Doppler Illuminator
3582871 Ellipictal Computer System, Morris Snyder (Navy), Jun 1, 1971, 367/3; 367/107; 701/300; 708/801 - determines sub position using sonobuoys

AN/ARR-502 Multichannel Sonobuoy Receiver (data sheet, data sheet)

AQA-7(V)1/2 Directional Acoustic-Frequency Analysis and Recording System (DIFAR)

ASQ-114 digital computer has a memory loaded with a large number of sound profiles of submarines and radar- and radio signals for comparing ESM measurements

Forward Looking Infra Red (FLIR) replaced the Low Light Level TeleVision system (LLLTV)

ASR-3 Sonobuoy Reference System (SRS) - used multiple antennas to determine bearing to sonobuoy
Digital magnetic Tape System (DMTS) -

Integrated Acoustic Communication System (IACS) - sub coms

Litton LTN-72 navigation system used with the INS and Doppler navigation systems

ALR-66 (Wiki) ESM systems (Wiki) using the Adaptive Controlled Phased Array System (ACPA)

Deinterleaver Technology for Future ESM systems, Dec 1992 NSWC - each pulse received from a single emitter can be agile in frequency, pulse width, pulse amplitude, pulse repition interval, but not direction. So using the Pulse Descriptor Word from the ESM sensor a future deinterleaver can sort out each emitter and differentiate between friendly and hostile emitters. ESM systems mentioned:
Racal SADIE
IBM Associative Comparator
Anaren ESM Processor
ALQ-32 Inner Processor

Instantaneous Frequency Measurement (IFM) receivers are part of the ESM sensor. But this type of receiver can have problems with two signals at the same time or with a CW signal anywhere in it's frequency range. The proposed configuration is to use narrow band receivers (many channels) and for each channel two paths, one for angle of arrival and the other for characterization of the received signal.

1^st Generation

I think this outdoor intrusion sensor was made by modifying a sonobuoy. The Automatic Radio Frequency Buoy (ARFBUOY) may be this unit or something very similar.
See Popular Mechanics March 1976 "War watch in the Sinai" references the "electronic battlefield" aka the "McNamara Line" (Wiki). Mentions sensors:

MAGID - Magnetic Intrusion Detector can discriminate between T-48 and T-60 tank or between 2-1/2 Ton and 5 Ton truck.
Noiseless Button Bomblet (NBB) - a transmitter triggered my the slightest movement
T-4 - senses RF from vehicle ignition systems.
MINISID III - combines a geophone with another sensor (an IR beam breaker for example) and does not transmit an alarm until both sensors are being triggered.

See the web page: http://1stwave553rdreconwing.com/AboutUs.html
and/or search on keywords: John T. Correll, Igloo White (Wiki), the McNamara Line (Wiki),
AF Magazine Nov 2004 - Igloo White the quotes below are from this article.

http://en.wikipedia.org/wiki/Igloo_White#Sensors_and_Weapons
http://en.wikipedia.org/wiki/McNamara_Line

The barrier would consist of a 20,000 air dropped listening devices combined with 240,000,000 Gravel mine and 300,000,000 Button mines and 19,200 Sadeye cluster bombs at a cost of around one billion dollars a year, not including 1.6 billion dollars for research and development, and the construction of a 600 million dollar command center in Thailand.

Spikebuoy - seismic sensor

"The Spikebuoy (66 inches long, 40 pounds) planted itself in the ground like a lawn dart. Only the antenna, which looked like the stalks of weeds, was left showing above ground."

ADSID

(Air-Delivered Seismic Intrusion Detector) sensed earth motion to detect people and vehicles. It resembled the Spikebuoy, except it was smaller and lighter (31 inches long, 25 pounds). It was the most widely used sensor in the program.

Acoubuoy - microphone

"The Acoubuoy (36 inches long, 26 pounds) floated down by camouflaged parachute and caught in the trees, where it hung to listen."

Arfbuoy - repeater

Photos courtesy of Dennis Starks

ARFBUOY Acoubuoy This is an 18 pound steel cylinder 4-3/4"x22". It's designed to be air dropped with a drag chute and get hung up in the trees. There is a central tape whip and four ground plane tape whips each 17" long. which is a quarter wave at about 190 MHz.

The central gold colored thing is the microphone. Note all the holes in the front to let sound it and protrct the microphone from tree limbs.
	Battery This is a battery type I don't recognize. If you know about it please let me know what it is.	Sound Observer (Locator) Remote Microphone. It's identical to the mike in the acoubuoy. This is the same mike that's in the photo at left with the question mark. The 5 socket connector is marked: 7004 Deutsh DBA36-10-5SN-10-6032 The contacts are numbered 1, 2, 3, 4 (but no 5). There's a knurled and slotted screw head on the back that can be unscrewed about 1 turn, maybe to normalizing the pressure inside to match atmospheric. See RT-1185 for a similar application.

USQ-42 Receiver

R-1617A/USQ-46 Receiver

Description

Operation

When powered there is no indication on the front panel that the receiver is working. Pressing the test buttons to the right of the display will light up each row of digits if the DIM control is clockwise. If a handset is connected and the SQUELCH is turned down you can hear hissing in the speaker.

GSQ-171

An eBay ad showed the GSQ-171 beside the USQ-46 receiver. It has what appear to be Vietnamese markings.
What is this: Contact me

TS-2963 Test Set (Transmitter)

PP-6446A/USQ-46 Power Supply (Receiver, Test Set)

2422337 Submarine Detecting Buoy, C. Chilowsky, Jun 17 1947, 367/4; 441/11; 441/25; 441/26; 441/28; 455/99 -

Calls:
1249486 Sunken Ship Locating Device, Dec 11, 1917, 441/25; 242/156; 441/26 -
1195317 Observation-buoy and Fire Control for Floating Mines, Aug 22 1916,
1426337 Signaling Apparatus for Detecting Submarines, Aug 15 1922,

455/97; 102/402; 114/240.00R; 174/77.00R; 174/138.00R; 174/153.00R; 200/83.00R; 294/111; 313/243; 313/553; 343/709; 343/896; 441/11; 455/99 -
- sub hits net closing circuit keying a transmitter that uses a code wheel to identify it's serial number.

1427560 Means for Detecting Submarines, Aug 29, 1922, - another net type
1430162 Apparatus for Detecting and Indicating the Presence of Submaring Boats, Sep 26, 1922
1466284 Detecting System, (Western Electric) Aug 28, 1923, 367/122; 340/384.1 - multiple zone vibration detection
1610779 Signalling Apparatus, (GE) Dec 14 1926, -
1749444 Signal System, - police
2320610 Apparatus for Detecting and Indicating the Presence of Submarine Boats - net type

2438926

Magnetostrictive supersonic transducer,

Mott Edward E,

Bell Telephone Labs Inc,

Apr 6, 1948,

367/168, 381/190, 335/215, 310/26

2417830

Compressional wave signaling device

2448713

Radio listening buoy,

Hansell Clarence W, Rca Corp, Dec 2, 1944, Sep 7, 1948, 367/3, 343/709, 441/13, 455/99, 343/702

2465696 Method and Means for Surveying Geological Formations, LeCoy C Paslay, Mar 29 1949, 367/23; 114/245; 346/33.00C; 367/16; 367/20; 367/155 -

Calls:
1378960 Method and Apparatus for Detecting Under Water Vibrations, J.W. Horton (WE), May 24 1921, 367/130 - submarine specific
1584613 Wave Detector, D.F. Comstock et al, May 11 1929, 367/130; 361/280; 361/283.1; 361/285; 367/129; 367/154 - sub detection directional array of sensors
2212988 Apparatus for Transmitting and Recording Shot Moments, D.K. Kirt (Gulf Oil R&D), Aug 27 1940, 367/77; 367/55 - seismograph prospecting
2241428 Apparatus for Underwater Seismic Surveying, D. Silverman (Standard Oil), May 1941,
2283200 Method and Apparatus for Subsurface Mining, J.W. Flode, 1942 - seismograph prospecting
2324378 submarine Prospecting, J.W. Flude, 1943 - seismograph prospecting
2440903 Underwater Transducer, F. Massa (Brush Dev Co), May 4 1948, 367/160; 381/163; 381/190 - piezoelectric or magnetostrictive transducers in towable rubber hose.

2521136

Hydrophone,

A. Thuras, (USA) Sep 5, 1950, 310/26, 381/190, 367/168, 381/163
2593432

Automatically operated radio buoy,

Freas Raymond L,

Apr 22, 1952,

455/96, 455/99, 244/149, 455/91, 343/705, 455/98, 441/11, 455/97, 343/709, 367/4, 343/902

2629083 Expendable radiosonic buoy, Barkson Joseph A, Mason Russell I, Mcnary James C, Filed: Sep 21, 1944, Pub: Feb 17, 1953, 367/3, 343/709, 455/99, 441/33, 441/23, 343/705, 343/901 -

2641751 Hydrophone Casing, (Navy), 367/173, Jun 1953 -

Calls:
806730 Device for locating and recovering sunken articles, Dec 5, 1905
1252877 Means for indicating the position of self-propelled vessels, Jan 8, 1918 - buoy released from practice torpedo at end of its run
1292755 Submarine detector or telltale, Jan 28, 1919 - net with alarm
1427560 Means for detecting submarine boats, Sperry Elmer A, Aug 29, 1922 - net with alarm
2261513 Mechanical boat lifter and indicator, Nov 4, 1941 -
2361177 Method and apparatus for the detection of submarines by airplanes, Oct 24, 1944 - fly in circle with long cable attached to hydrophone
2396960 Means for locating lost aircraft Mar 19, 1946 -

2644243 Control Compass, (Navy), 361/280; 33/363.00Q, Jul 1953 -

Calls:
1639000 Wave modulation, Western Electric Co, Aug 16, 1927 -
2036833 Tuning condenser arrangement
2116103 Compass for automatic pilots, May 3, 1938 -
2277027 Telemetric system, West Instr Co Inc, Mar 24, 1942 - servo compass repeater
2319212 Photoelectric control device, May 18, 1943 - used to read compass rose
2346839 Baking utensil?
2363500 Gyro magnetic compass system, Sperry Gyroscope Co Inc, Nov 28, 1944 -

2749436 Sonobuoy, R.H. Rines et al, Jun 5 1956, 455/99; 342/6; 367/3; 455/91; 455/107; 455/116; 455/129 -

Calls:
2063944 Means for Locating Crashed Airplanes, Jan 22, 1957, 116/210; 244/1.00R; 244/137.1 - based on sonobuoy technology
2063945 Diaphragm and Method
2063946 Sound Communication System
2063947 Compensator
2539594 System and Method of Communication
2361177 Method and Apparatus for the Detection of Submarines by Airplanes, C. Cilowsky, Oct 24 1944, - flying in circle lowers cable with hydrophone
2397844 Signaling Apparatus, W.W. Dewhurst (RCA), Apr 2, 1946, 367/3; 73/322.5; 114/198; 138/89; 441/11; 455/99; D10/107 - sub Tx buoy
2422337
2448713 Radio Listening Buoy, (RCA), Sep 7, 1948, 367/3; 343/702; 343/709; 441/13; 455/99 - very early sonobuoy
2448787 Apparatus for Detecting and Locating Enemy Vesels, (Ferrel Ind), Sep 7, 1948, - above surface microphone

2758203

Sonobuoy,

Harris Wilbur T, Harris Transducer Corp, Aug 7, 1956, 455/99, 342/5, 367/4 - shock absorber in cable to reduce noise

2817909 Training Device for Operators of Underwater Detection Appratus, B.M. Taylor, et al, Dec 31 1957, 434/9; 434/10
Calls:
1731127 Signal Control System (railroad), Oct 8 1929
1859423 Sound Recording - multiple needles for echos
2039405 Remote Metering System (AT&T) -
2066156 signaling Means, Apr 25 1929, - relative motion
2206156 Conveyer?
2206036 Distance Measuring Apparatus and System, J. Herson, Jly 2 1940, - optical aircraft altitude blind landing
2329612 Apparatus for Training Aircraft Pilots, G.E. Hill et al, Sep 14 1943, - includes real time position output
2332523 Ground Track Tracer and Landing Recorder, E. Norden et al, Oct 26 1943, - servo controled pen recorders
2358793 Navigation Instruction Device, C.J. Crane, Sep 26 1944, - scaled movement of student over floor
2373560 Sound Recording Method and Apparatus, J.M. Hanert (Hammond Inst Co), Apr 10 1945 - adding vibrato
2375004 Training Apparatus, May 1 1945 - sound and recoil of a real gun
2444477 Automatic Miniature Radio Range (A-N), 1948 - used with pen recorder
2452038 Photoelectric Radio Compass Trainer Control, 1948 - based on scale map
2459150 Interception Trainer 1949 - call "Link" patents: 1825462, 2099857

2828475 Remote Control or Measurement Indicating Means, (Sec of Navy), Mar 19 1958 - Sonobuoy that adds direction to sound in addition to just omni directional listening

Calls:
1571006 Signaling system, Western Electric Co, Priority: Sep 8, 1920 (16 year delay) Pub: Jan 26, 1926 - motor based secret signaling
1592940 Secret signaling, Western Electric Co, Priority: Sep 9, 1920 (16 year delay) Pub: Jul 20, 1926 - motor based secret signaling
1718497 Telemetric system, Gen Electric, Jun 25, 1929 - servo remote indicating
1732741 Duplex radio transmission system, Westinghouse Electric & Mfg Co, Oct 22, 1929 - combined audio & coded signals from a single source
1913512 Meteorological indicator, Jun 13, 1933 - radio transmitter hung below tethered - early radiosonde
1928969 Well survey instrument, Union Oil Co, Oct 3, 1933 - probe in pipe sends attitude info to surface
2089987 Means for operating a repeating device, Pioneer Instr Co Inc, Aug 17, 1937 -
2103847
2151747
2177493
2316317
2334704
2357975
2361177
2448787

3022448 Modular sub-assembly, Feb 1962

3093808 Air-dropped miniature sonobuoy, Gimber George A, Scarcelli Albert F, Tatnall George J, Secretary of the Navy , Jun 11, 1963, 367/4, 441/33, 441/25, 343/709, 455/99 - Prior art sonobuoys were 3' long, 5" diameter and weighed 16 to 20 pounds limiting aircraft time on station and had a max depth of about 50'. This one is 15" long, about 3" dia and weighs about 5 pounds with a max depth of 300'.

3132322

Radiosonic buoys,

Guy Maes, Electronique Appliquee, Feb 9, 1959, May 5, 1964,
367/4, 340/870.28, 343/710, 441/23, 455/127.1, 455/99, 441/11, 340/870.1, 343/880

3281765 Minature Sonobuoy and Cable (ITT), Oct 25, 1966 - small dia (0.030") cable which acts as a spring, Ni-Cad batt charged prior to use.

Calls:
2422337
2641751 Hydrophne Casing, Bernier Jr Hector F, Mason Russell I, Ripken John F, Us Navy, Filed: May 11, 1944, Pub: Jun 9, 1953, 367/173 - about playing out the line supporting hte hydrophone below the buoy.
3093808 Air Dropped Miniature Sonobuoy, (Navy), Jun 11, 1963, 367/4; 343/709; 441/25; 441/33; 455/99 -

3290642 Directional Sonobuoy, (Navy), Dec 6, 1966, 367/4; 367/120; 367/129; 441/33 - weight driven rotating sensors

3309649 Sonobuoy with Depth Selection Capabilities, Sanders Assoc, Mar 14 1967, 367/4; 441/33 -
3377615

Compliant suspension system,

Sparton Corp, Apr 9, 1968
3460058 Radio Sonobuoy, (ITT), Aug 5, 1969, 367/4 - operates below thermocline
3671928 Automatically energizable Sonobuoy, Aquatronics, Jun 20 1972, 367/4; 441/11; 441/33 - some similarity to acoubuoy.
3720909 Directional Hydrophone System, Spartan Corp, Mar 13 1973, 367/173 - seismic sensors in sonobuoy

Calls:
3451040 Spring Suspension for a Low-frequency Geophone, W.R. Johnson, )MarkProd Inc), Jun 17 1969, 367/183 -

Calls:
2751573
3344397

2390328 Directional Seismograph Pickup, R.J. Roberts (Std Oil), Dec 4, 1945, 367/185; 340/870.35 -
2856594 Seismic Detector, K.W. McLoad (Vector Mfg), Oct 14 1958, 367/154; 73/652 - underwater
3325778 Seismic Sonobuoy, S.S. Ballard (Sanders Assoc), Jun 13, 1967, 367/21; 330/51; 330/124.00R; 330/278; 367/66; 455/99 -

3377615	April 1968	Lutes
3281765	October 1966	Taplin
2435587	February 1948	Harry
3372368	March 1968	Dale et al.
3539979	November 1970	Crall

3786403 Underwater Acoustical Detection, Navy, Jan 1, 1974, 367/4; 441/25; 441/26 - SIDECAR,

Calls:
app 549209 Apr 19 1966 A.S. Will et al
app 452460 Apr 18 1965 Urick et al
app 502713 Oct 22 1965 Urick

2422337	June 1947	Chilowsky
3222634	December 1965	Foster
3275976	September 1966	Farmer

3921120 Float Actuated Release Mechanism, Sparton Corp., Nov 18 1975, 367/4; 116/209; 441/33 -

Calls:

2778332	January 1957	Talbot
3093808	June 1963	Tatnall et al.
3140886	July 1964	Cotilla et al.
3220028	November 1965	Maes
3309649	March 1967	Ballard et al.
3646505	February 1972	Kirby
3701175	October 1972	Widenhofer

3944964 Air Dripped Linear Acoustic Detector, (Navy), Mar 16, 1976, 367/4 -
3991475 Depth selecting spool device, Navy, Nov 16, 1976, 116/209; 367/4; 441/24 -

calls:

3093808	June 1963	Tatnall et al.
3262090	July 1966	Farmer
3921120	November 1975	Widenhofer

4096598 Selected Depth Mooring System, R.J. Mason, 441/25, Jun 1978 -

Calls:
3631550 Mooring Devices, (EMI), 441/25, Jan 4, 1972 -

4114137 Directional Sonobuoy, (Navy), 367/171; 441/1; 441/28, Sep 12 1978

Calls:
768568
1345717
3382481
3803540
3864771

4143349

Cable depth selector and coil shunt penetrator, (

Bunker Ramo Corporation), Mar 6, 1979, 367/4, 441/1, 439/391 -
4186370 Stabilized sonobuoy suspension, Raytheon, Jan 29, 1980, 367/4; 367/130; 441/11; 441/33 -
4189786 Radio Buoy Assembly, R.E. Adler, Feb 19 1980, 367/4; 367/5; 367/133 -
4357688 Low cost sonobuoy, Navy, Nov 2, 1982, 367/4; 367/173 -
4358834 Self-deploying Buoy System, Navy, Nov 9, 1982, 367/4; 367/173 -

4493664 Sonobuoy Float Inflation and Depth Selection Initiators, Navy, Jan 15, 1985, 441/7; 222/5; 367/4; 441/26; 441/30; 441/33 -
4530269 Remotely Initiated Speration Latch Assembly, Burroughs Corp, Jul 23 1985, 89/1.14; 102/293; 102/378; 220/261; 367/4; 367/173; 403/2 - electrical match for seperation

4590590 Sonobuoy Multiple Depth Deployment Apparatus, Magnavox, May 20 1986, 367/4; 441/25; 441/33 -
4727520 Cable Deployment Unit, Sparton of Canada, Feb 23, 1988, 367/4; 367/3; 441/25 -
4901288 Compact cylindrical sonobuoy, Sparton Corp, Feb 13 1990, 367/4 -
4924445 Sonobuoy Cable Pack, Royal Navy, May 8, 1990, 367/4; 114/326; 367/3; 441/8 -
4927057 Automatic Infiltrator for Inflatable Articles, Inflation Tech, May 22, 1990, 222/5; 222/23; 222/41; 222/52; 222/63; 222/93; 222/94; 441/93 -
5076468 Squib Inflator Adapter, Halkey-Roberts Corp, Dec 31, 1991, 222/5; 222/91; 441/93 -
5197036 Sonar Array Mounting for Sonobuoy, Mar 23, 1993, 367/4; 367/153 -
6400645 Sonobuoy Apparatus, (Navy), Jun 4, 2002, 367/4; 367/3; 367/153 - opens sort of like an 8-sided umbrella

SONAR
4998224 System for providing improved reverberation limited sonar performance, Mar 5, 1991
5138587 Harbor Approach- Defense Embedded System, (Navy), 367/136, Aug 1992
5144487 Expendable moving echo radiator, (Navy), 367/1; 367/137; 367/165, Sep 1992 - countermeasures equip
5808580 Radar/sonar system concept for extended range-doppler coverage,
6018493 Sonar Suspension Apparatus, Dowty Maritime Sys, Jan 25, 2000, 367/16; 367/20; 367/153; 367/155; 367/165; 441/33 -

Launching

Photo from Wiki Sonobuoy page

From Ships and Aircraft of the U.S. Fleet (2005):
The p-3C Orion. . . tail-mounted ASQ-81 Magnetic Anomaly Detector (MAD) and 48 external (fuselage) sonolbuoy chutes and four in-flight reloadable(internal) chutes; a total of 84 buoys normally are carried.

Sonobuoy
being loadeed on P-3 Orion from outside prior to takeoff

2707904 Sonobuoy Dispensers, Breeze Corp, May 10, 1955, 89/1.51; 367/3 - revolver,
3451306 Safe and Arm Ejection System, Susquehanna Corp, Jun 24 1969, 89/1.1; 89/1.51; 102/259; 102/357 -
3905291 Cartridge-actuated Device and Launching Assembly using same, G.T. Corbin, Sep 16 1975, 102/430; 42/96 -
4026188 Modular Buoy System, Sandars Assoc, May 31 1977, 89/1.51; 102/351; 102/352; 102/354; 102/406 -
4263835 Sonobuoy Launcher System, Navy, Apr 28, 1981, 89/1.51; 89/1.3; 89/1.806; 89/1.818 - bouys loaded from outside

4397433 Revolving-cylinder jettison device for transporting and releasing buoys on and from Aircraft, , Aug 9 1983, 244/137.4; 89/1.51; 89/1.801; 244/118.1 -
5052270 Multi-sonobuoy launch container with constant force spring, Navy, Oct 1 1991, 89/1.51; 244/137.4 -
7278416 Pneumatic projectile launcher and sonobuoy launcher adaptor, Lockheed-Martin, Oct 9, 2007, 124/72; 89/1.51 -

Reserve Battery

A reserve battery is one where the electrolyte is stored seperated from the electrodes. They can sit for decades and when activated (heat, water, gas, mechanical force) are then a battery.

2590584 Sea Water Battery, Bel Tel Labs, Mar 25 1952, 429/119; 429/152; 429/231.6 - silver chloride on silver & magnesium electrodes in salt water.
2669596 Reserve Battery Enclosure, Navy, Feb 16 1954, 429/8; 116/1; 429/119 -
2699461 Defered Action Battery, Burgess, Jan 11 1955, 429/119; 429/152; 429/162 -
2715652 Electric Battery for Airborne Equipment, Eagle-Picher Co, Aub 16 1955, 429/118; 429/152; 429/162 : -40 to 160 def F operation
3178316 Reserve Battery, Servel Inc, Apr 13, 1965, 429/119; 429/130; 429/210 -
3767933 Power Supply having a Plurality of Power Sources that are Swquentially Placed on the Load One at a Time, Oct 23 1973 307/48; 307/66 -
3966497 Seawater Battery, ESB Inc, Jun 29 1976, 429/119 -
4601961 Bilaminar Seawater Battery, Navy, Jul 22, 1986, 429/119; 429/127 -

Calls:

5395707 Environmentally safe water-activated battery, ACR Elec, Mar 7 1995, 429/119; 429/128; 429/130 -

Got this hydrophone from Fair Radio. It consists of a bladder just under five feet long and about three inches in diameter filled with mineral oil (or something similar). Inside there are eight cylindrical Rochelle Salt Crystal doublets, each about three inches long with about a three inch gap between sensors (series or parallel connection?).

In the Combat Information Center magazine for July 1944 (Vol. 1 No. 5) there's an article on harbor defense that mentions both a sonobuoy with vertical hydrophone array (radio has 12 mile range and hydrophone has 1,000 yard range) as well as multiple hydrophones laid on the bottom and connected to multi-conductor cable.

At the cable end of the hydrophone is a matching transformer with 25 Ohm output impedance. Frequency response of 1Hz to 20 kHz (i.e. young human hearing range).
The internal construction seems to be steel cylinders spot welded to two steel rods that tie them toghther. The crystals are glued into the cylinders and wired in parallel.
If buried in the ground as is the mineral oil will leak out leaving air voids. If repackaged in a PVC pipe the sound would travel up and down the pipe wall which doesn't happen with the current rubber bladder. So maybe some type of flexable hose would be a good replacement?

The idea is to bury it and have excellent low frequency (below 20 Hz) response. The Infra sound sensors use garden hose with a pin hole leak.

Official Description:

Hydrophone, U. S. Navy Harbor Detection, Sonic, NT-51038F; P/O type JR-1 Harbor Detection Equipment.

Sensitive listening, frequency range 1 - 20 thousand cycles per second; with 8 Rochelle Salt Crystal Doublets each approx. 3" x 2" x 1", in metal frame w/matching transformer to 25 ohm line, in Castor (?) Oil, encased by heavy rubber jacket 56" long x 2 1/2" in diameter; with 9 foot rubber covered cable 1/2" O.D. w/2 flexible copper wires insulated, plus 2 steel strain wires; to be used down to 400ft. depth while withstanding high pressure explosion waves. Mfg by Brush Development Company.

How can the transformer work over that frequency range?

3 Feb 2012 - When the 999 average spectrum plot finishes I'll have a look at the impedance.

Fig HP1

Hydrophone, U.
S. Navy Harbor Detection, Sonic, NT-51038F; P/O type
JR-1 Harbor Detection Equipment.

Fig HP2 Transformer

Hydrophone,
U. S. Navy Harbor Detection, Sonic, NT-51038F; P/O
type JR-1 Harbor Detection Equipment - Transformer

		White	Red	Black	Green	Blue
Case Ground	White	-	Opn	Opn	Opn	Opn
	Red	-	-	Opn	Opn	Sht
	Black	-	-	-	Sht	Opn
	Green	-	-	-	-	Opn
	Blue	-	-	-	-	-

The Red and Blue terminals are physically in line.
The Black and Green terminals are physically in line.
The White wire is not an electrical connection but rather is where a couple of steel cables attach for supporting the weight of the hydrophone.
It's not clear what this is.

HP 4395A Plot 1 Hz to 20 kHz RBW: 1 Hz, True RMS detection, 16 averages:
8 Crystal
Hydrophone spectrum 1 Hz to 20 kHz into 50 Ohm HP 4395A

HP 4395A Plot 1Hz to 20 kHz RBW: 1 Hz, True RMS detection, 999 averages (54.6 hours):
HP 4395A
Plot 0 to 20 kHz RBW: 1 Hz, True RMS detection, 999
averages (54.6 hours)

HP 4395A
Plot 0 to 20 kHz RBW: 1 Hz, True RMS detection, 999
averages (54.6 hours)

HP 4395A Z transform Impedance Real & Imaginary
HP 4395A Z
transform Hydrophone Impedance Real & Imaginary

HP 4395A Z transform Hydrophone Impedance Smith Chart with Marker List
HP 4395A Z
transform Hydrophone Impedance Smith Chart with Marker
List

GEO_ID - TRC-3, PEWS, USQ-42, Turd
GSQ154 - All GSQ-154
GSQ160 - Frequency Disconnect -GSQ-160, USQ-46, TS-2963, PP-6446 - TCw - cylindrical module pinouts.
GSS26 - AN/GSS-26 minimal info
Intrusion Alarm Patents
USQ_Rx - Igloo White, USQ-42, USQ-46 details,
PSR-1 - now on it's own page (July 2007)
Modular Outdoor Intrusion Sensors (REMBASS?)

Astronomy - UFOs - Richard Muller Physics Lecture 11 - Waves 1

Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet, 18th Edition (2005) by Norman Polmar
The Ears of Air ASW: A history of U.S. Navy Sonobuoys (2008) - Holler, Horbach & McEachem

Sonobuoy Based Outdoor Intrusion Detectors

Background

Submarines & the Noises they Make

Sonobuoys

CNU-239/E Shipping Tube

A Size

Hydrophone

Bathythermograph (Wiki: BT)

Service Life

Radio Transmitter

Sonobuoy Radio Channels

1st Generation

2nd Generation

3rd Generation

USQ-46 (USQ, below)

Black Box

Command Function Select (CFS)

Directional Frequency Analysis & Recording type acoustic sensor (DIFAR)

DIFAR Patents

Earth's Field Magnetic Detectors

Magnetic Anomaly Detector (MAD) Patents

Bathythermograph Patents

Reserve Batteries

Salt water activated magnesium

Salt water activated silver chloride

Table of Sonobuoys

Operation

Battery

Sonobuoy Aircraft Systems

Sippican Ocean Systems SSXBT Model ST-1

Outdoor Intrusion Detectors based on Sonobuoy Technology

Construction

1st Generation

Spikebuoy - seismic sensor

ADSID

Acoubuoy - microphone

Arfbuoy - repeater

ARFBUOY Acoubuoy

USQ-42 Receiver

R-1617A/USQ-46 Receiver

Description

Operation

GSQ-171

TS-2963 Test Set (Transmitter)

PP-6446A/USQ-46 Power Supply (Receiver, Test Set)

GSQ-154

GSQ-160

Patents, Sonobuoy

Launching

Reserve Battery

Magnetic Anomaly Detector (MAD) (Wiki)

Hydrophone

Roswell Connection

Unknown Sonobuoy - What is it?

Underwater Communications

Related

Books

Links

1^st Generation