The Yaesu VX-7R is a very small radio that operates on 6 meters, 2 meters & 440 MHz. 5 Watts output power. It's rumored to be hackable in many ways and to have it's origins in the Japan Defense Radio 6.
Closely related radios are the:
Wiki page on VX-7 series radios.
The minimum frequency step is 5 kHz so this radio can not monitor 3996 kHz SSB.
Operation Manual pages:
14 (mono band selection)
64 & 65 Smart Search Operation
90 single scan or scan untill 31 memories are filled
In this mode the radio scans one of the bands and stores in memory any active frequencies.
To get into smart scan, first you need to be in Mono band mode (i.e. only one frequency displayed on the LCD. If you're in dual mode then press and hold MAIN for a second or two.
Page 65 of the manual details how to set single sweep or continuous sweep mode.
When the sweep ends you can turn the outer dial to review the frequencies logged. I got:The Win System is related to the Internet Radio Linking Project
147.120- Win System 90 Willits CA K7WWA 147.120 (+) 103.5 Laughlin ridge, 3,250' + 100' A 1460
154.310 - CDF Dispatch Green
162.525 - Eureka Weather
Here's a spectrum plot made using the HP 4395A with max hold.
In Smart Scan (see above) the radio scans once in the up frequency direction and then once in the down frequency direction and stops.
If you want the scan to keep going then this mode allows scanning between a set lower and upper frequency limit.
There are 20 upper and 20 lower frequency limit memories so a number of different scans can be programmed.
The description on page 61 of the operating manual is missing the key step and that's to start the scan press: [Mon/F] then .
57 Scan-Resume Technique (3/5/10 seconds, Busy, Hold)
Northern Amateur Relay Council of California -Working your first Amateur Satellite! -
|scanner antenna Radio Shack
||2 meter Max hold Spectrum Plot made with
Marker 1 might be showing some Doppler?
Aircraft coms, max hold
Radio Reference - Finding Air Traffic Frequencies
Commercial airlines fly over this area, but at about 30,000 feet or more?
Howard Forrest: 151.38500
TacNet's: 2, 3, 4, 6, 11
123 to 127 MHz multi day spectrum plot
150 to 154 MHz multi day spectrum plot
The eBay ad had MH-57A4B as part of the title, but this is a made in China mike. When used as a speaker it's much louder than the speaker that's built-in the radio so just for the improved audio it's a good thing.
There's what appears to be a socket on the bottom just next to the cable, what's that for? answer from J. Stark: an earpiece. That makes a lot of sense.
Speaker Mike Fig 1
Speaker Mike Fig 2
Note 1 - meaning of pulling low with resistor
Mike & PTT
Mike & PTT PTT PTT Tip (PTT)1 White /Start
This cable allows making changes to the radio that formerly required soldering jumpers as well as maintaining the data stored in the radio.
Maxton model: RPC-Y7R-U p/n: PCY1009
This is the stock battery pack that comes with the radio.
This display shows Li-Ion 8.3 V (or whatever the battery voltage is)
aka Car Charging Cable.
The display shows Ext DC 12.6 Volts.
Holds 2 AA batteries.
The display shows L20 Dry cel 4.4 Volts.
Shown below with SMA(m) to BNC(f) adapter.
OPEK HVU-610 Tri-Band 52/146/440 MHz Fold-over Antenna w/ NMO Mount
The antenna measures a DC short between be NMO center pin and threads.
That does not seem correct. Have asked Opek about it.
Workman PM-5 NMO 5" Magnetic Antenna Mount with PL-59
When the antenna is screwed on the base center rotates.
Got this for my car that's kept in a garage. But am concerned that I'll forget to fold it over.
There's nothing to keep the brass NMO base from rotating
other than how tight the nut is torqued. Turning the nut
breaks the center wire.
Also there should have been a thick washer under the nut to
cause the NMO center contact to be at the proper height.
As received the center contact was so high the threads only
went on a little more than one turn.
This is a poor design. As received the center post was sticking up way too far (maybe 0.2"). There is a special bolt with a center conductor that clamps the parts together.
It has a solder post in the slot cut into the head. In order for the tip of this bolt, which is the antenna center contact, to be at the correct height there needs to be the correct thickness of parts between the head and the brass NMO threaded disk. If these parts are added on the head end then the head protrudes below the magnet and would destroy a car's paint. When these parts are added at the top under the brass NMO disk it raises up the disk.
Page 97 of the Operating Manual has the instructions for installing the sensor.
Note: Hardware jumpers 4 & 5 are soldered, the other are open.
Open J4: Freeband TX: 40.000Mhz - 224.995Mhz & 300Mhz - 579.995Mhz
Open J5: Mars/Cap TX: 50Mhz - 54Mhz 140Mhz - 174Mhz & 222Mhz - 225Mhz & 420Mhz - 470Mhz.
Note: No single antenna is good for all the above Tx frequencies, and if you Tx into a high VSWR it's probably you will let the smoke out of the final amplifier.
Note: This can also be done in software.
There are alternate displays such as Weather, Barometric pressure, Time, etc.
Display Setup #4 Display Mode (pg 86)
Should allow "ALL" to be displayed when power is off, but so far it's not working.
---------------------- next day ---------------
I think what's happening is that if I power off the radio with the charger plugged in, it just goes into charge mode and does not display anything.
But, if I turn off the radio when there's no external power, it goes into the display ALL mode.
(I've been told this will drain the battery in 3 days).
Now I can plug in the charger and still see the data display.
But I don't know if it's charging or not.
I just pulled the battery and the display is still there, so it must be using external power.
When the radio is ON use Set Mode / Measurement #1 (pg 91) to choose between:
Baro, ALT1, Wx
Optoelectronics makes a number of frequency counters that have the ability to show the frequency of a nearby transmitter. Some of these have an RS-232 output that can tune a receiver, they call it Reaction Tune. It's based on the ICOM CV-I protocol. Product Comparison Chart
2.5mm mono for TTL (Reaction Tune): Tip: TxD, Shield/Sleeve: Ground
This is the interesting one because it can measure the frequency of a digital signal (pulse of RF).
Digital Scout Serial Interface Specification 1.1 -
3.5mm stereo for RS-232: Ring: RxD, Tip: TxD, Sleeve: Ground
5471402 Frequency Counter, Optoelectronics, Inc., Nov 28, 1995, - method of using a high gain amplifier between an antenna and frequency counter.
Improved frequency counter with reduced false correlations,May 29, 1997 -
Frequency counter with reduced false correlations,Jan 20, 1998 -
Explorer Near Filed Test Receiver
This is also very interesting. It too has "Reaction Tuning".
Paint Ball Bowman - real Bowman on same page
PRC-152 Falcon III TRI Replica Radio - BaoFeng Radios
Willits Amateur Radio Society (WARS) -
Hampedia - VX-7() Mods -
YouTube - Yaesu VX-7R Out of Band Modification