Yaesu VX-7R Handheld Transceiver

Brooke Clarke 2013 - 2017
Yaesu VX-7R Handheld
            Transciever


Background
Smart Scan
Programmed Memory Scan (PMS)
Repeaters in N. Calif.
Satellite Ops
Speaker Mike
    Audio Connector Pin Out
    3.5mm Socket Cable
    3.5mm Data Cable
DC Power
    Li Battery
    Cigarette Lighter Cable
    AA Battery Adapter
Antenna
SU-1 Barometric Pressure Altimeter
Optoelectronics Scouts
My Related Pages
Links

Background

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: 

Japan Defense Force 6
Vertex Standard VX-7 - at retailer
HX470s Marine radio - pdf brochure
FTA-720 Aviation radio

Wiki page on VX-7 series radios.

The minimum frequency step is 5 kHz so this radio can not monitor 3996 kHz SSB.

Smart Scan

Operation Manual pages:
14 (mono band selection)
64 & 65 Smart Search Operation
90 single scan or scan untill 31 memories are filled

VX-7R Smart Scan

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:
139.995\
140.000/
145.595
147.115\
147.120- Win System 90 Willits CA K7WWA 147.120  (+) 103.5 Laughlin ridge, 3,250' + 100'  A  1460
147.125/
150.000
154.310 - CDF Dispatch Green
162.525 - Eureka Weather
164.010 -

The Win System is related to the Internet Radio Linking Project


Here's a spectrum plot made using the HP 4395A with max hold.

2 meter spectrum plot HP 4395A


Programmed (Band Limit) Memory Scan (PMS)

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 [1].

Manual pages:
57 Scan-Resume Technique (3/5/10 seconds, Busy, Hold)

Repeaters in N. Calif.

Northern Amateur Relay Council of California -
When
Memory
Rx
Tx
PL

L17
443.175
448.175
123
7 pm
L18
146.490
-
-
8 pm
L19
145.555
-
-
7:30 pm
L20
147.390
147.990
103.5

Satellite Ops

Phone Sat (Wiki) -  1U CubeSat (Wiki) -

Arrow Antennas - 146/437-10WBP - requires pointing Az, El, Theta, much better to have a pair of fixed eggbeater antennas with switchable polarity.

Working your first Amateur Satellite! -
Working the Easy Sats Down Under -

Getting Started on Amateur Radio Satellites - Satellites_RadCom_mar07.pdf

Overnight Spectrum Plots using 1/4 wave roof top antenna
scanner antenna Radio Shack
2 meter 1/4
                    wave antenna
2 meter Max hold Spectrum Plot made with HP 4395A


144 - 146 Mhz 1/4 roof top antenna N6GCE made
                  with HP 4395A
Marker 1 might be showing some Doppler?

Aircraft coms, max hold
108 - 138 MHz Spectrum Scan
Freq MHz
dBm

119.9625
-62

123.000
-51
Ukiah unicom (Wiki) - planes overhead
123.975

air tanker common ops frequency
125.850
-63
air show?
127.800
-59



From here down may be specific companies, rather than tied to the airport.
128.850
-64
Lifeflight or Fedex?
129.675
-68

130.050


130.500


131.2125
-62

131.475


132.225
-60

134.175


135.000


136.800


136.875



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
 2:  151.16000
 3:  151.17500
 4:  151.19000
 6:  151.32500
11: 151.44500

123 to 127 MHz multi day spectrum plot
Ukiah, CA 123 to 127 MHz spectrum plot, HP
                    4395A Max Hold

Freq
Description
123.000
Ukiah airport unicom
123.450
private ait to air chat
124.850
air to ground Air Traffic Control (airliners at 30k feet)
124.975
air to air?
125.050

125.800

125.850


150 to 154 MHz multi day spectrum plot
in process Jun 27, 2013




Speaker Mike

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
Yaesu VX-7R
                      Handheld Transceiver Speaker-Microphone
Speaker Mike Fig 2
Yaesu VX-7R
                      Handheld Transceiver Speaker-Microphone



Audio Connector Pin Out

Connector
Wire
Clone
Audio
Data
Command
Tip White
Mike & PTT
Mike & PTT PTT PTT
Tip (PTT)1 White /Start
/Tx
/Tx

R2 Blue
Clone



R1 Red
Speaker
Speaker

Sleeve Black
Ground
Ground

Note 1 - meaning of pulling low with resistor

3.5mm Socket Cable

This cable is wired:

Radio
3.5 Jack
Tip
R2
R1
Sleeve
VX-7R Audio Cable
                to 3.5mm Jack

3.5mm - USB Data Cable

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

Yeasu VX-7R
                  3.5mm - USB Data Cable

DC Power

Li Battery

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)

Cigarette Lighter Cable

aka Car Charging Cable.
The display shows Ext DC 12.6 Volts.

Yaesu VX-7R Handheld
                Transceiver Car Charging Cable

AA Battery Adapter

Holds 2 AA batteries.
The display shows L20 Dry cel  4.4 Volts.
Shown below with SMA(m) to BNC(f) adapter.

Yaesu VX-7R Handheld Transceiver
Yaesu VX-7R Handheld Transceiver


Antenna

Stock

Diamond

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.

OPEK HVU-610 Tri-Band 52/146/440 MHz
                      Fold-over Antenna w/ NMO Mount
OPEK HVU-610 Tri-Band 52/146/440 MHz
                      Fold-over Antenna w/ NMO Mount Workman PM-5 NMO 5" Magnetic Antenna
                      Mount with PL-59.
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.
Workman
                      PM-5 NMO 5" Magnetic Antenna Mount

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.


SU-1 Barometric Pressure Altimeter

Page 97 of the Operating Manual has the instructions for installing the sensor.


VX-7R SU-1
                      Barometric Pressure Altimeter
Note: Hardware jumpers 4 & 5 are soldered, the other are open.
VX-7R SU-1
                      Barometric Pressure Altimeter

Jumpers:
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.

VX-7R SU-1
                      Barometric Pressure Altimeter

VX-7R SU-1
                      Barometric Pressure Altimeter
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 Scouts

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

Scout

2.5mm mono for TTL (Reaction Tune):  Tip: TxD, Shield/Sleeve: Ground

Digital Scout

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

Spectrum Scout

5471402 Frequency Counter, Optoelectronics, Inc., Nov 28, 1995, - method of using a high gain amplifier between an antenna and frequency counter.
WO 1997019359 Improved frequency counter with reduced false correlations, May 29, 1997 -
5710710 Frequency counter with reduced false correlations, Jan 20, 1998 - 

Explorer Near Filed Test Receiver

This is also very interesting.  It too has "Reaction Tuning".

My Related Pages

ICOM R7100 receiver
NRD 545 Receiver
ICOM 706 Transceiver

BC125AT Scanner, Uniden

The 2-way paint ball radios are made to look like military radios but the internal circuitry comes from a small hand held radio.
Paint Ball Bowman - real Bowman on same page
PRC-152 Falcon III TRI Replica Radio - BaoFeng Radios

Links

Mendocino County Amateur Radio Communications Service (MCARCS) - Nets -

  • South Coast and Inland 145.470 - 103.5
  • Central Coast and Inland 147.390 + 103.5
  • North Coast and Inland 145.430 - 103.5
  • Fish Rock/Point Arena 147.270 + 114.8

Willits Amateur Radio Society (WARS) -

KC8UJN - software to access all radio functions
Standard VX-7 Tips - in Japanese
SourceForge -VX README -

Hampedia - VX-7() Mods -

http://groups.yahoo.com/group/yaesuvx7/

http://www.rtsystemsinc.com/

YouTube - Yaesu VX-7R Out of Band Modification

http://en.wikipedia.org/wiki/Yaesu_VX_series#Modifications_2


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Page created 23 April 2013.