Bowman

H4855 & H4855U

 AN/PRC-343

Personal Role Radio PRR

Integrated Intra Squad Radio IISR

© Brooke Clarke 2006 - 2010

Pouch, Radio, Antenna, 1 button PTT, Headset

Made by SELEX Communications (Marconi is on the label) and used mainly in the UK and by U.S. Marines.  Also by Australia.

There's a need for a short range radio for individual soldiers (intra squad).  There have been a number of different ones (PRC-68 Family,  the PRC-25, PRC-77 might be called inter squad) and this is yet another.  This radio appears to have been designed starting with a clean sheet of paper, a luxury that's not often available when the new radio needs to be compatible with all the older radios going back to the time of the gladiators.  This radio probably will not communicate with any other radio either military or civilian.

Controls

Chan: 16 Positions (1 shown) Off/Vol: 5 Positions (Off shown) Ant: SMAf recessed. Headset: LEMO 5 pin Bowman PTT for this radio Aux PTT: for Combat Radio (CR)

Setting Up

1. OFF/Vol to Off 2. Connect Headset     Push headset connector to seat it 3.Insert 2 AA batteries    (observe polarity markings) 4. Check that Chan is on proper channel 5. connect antenna 6. Switch Vol control on to medium position

Affiliating the Wireless PTT

The work PROGRAM on the wireless PTT is positioned over the bump where the reed switch is located in the PTT module. 1. Start with the OFF/Vol control at OFF. 2. Switch Vol on to a medium volume position.     Ascending Tones are heard. 3.  Press and hold wireless PTT      until ascending tones are heard a second time. 4. Release wireless PTT. 5. Note: decending tones heard of affiliating did not work.  If so, repeat steps 1 to 4.

De-Affiliating from the Wireless PTT

	1. Switch Off. 2. Switch On to medium volume. 3. Without pressing wireless PTT,      remove and return wireless PTT      to and from radio 5 times within      5 seconds of turning on radio.      Ascending tones heard. First de-affiliating then Affiliating WPTT. http://www.youtube.com/watch?v=FzbhupKswmk

Tones

Power on: three short tones if no WPTT is affiliated, or increasing frequency stair step tone if WPTT affiliated.
Power off: four medium length tones and one long tone.
Battery Low: four tones alternating in frequency.
Combat Net Radio call waiting: Three medium tones and one long tone repeated every five seconds. (only when a Dual PTT equipped radio)
Wireless PTT affiliation: stair step of eight tones upward in frequency.  Repeated if successful.  Downward sequence of eight tones if failed.
Volume and Channel changes: one beep per step
Turned off by holding PTT while turning on the radio.

To Disable Tones

1. Switch off the radio.
2. While holding down the radio PTT switch turn power on.  Now instead of hearing the tones, the audio will be blanked at the times when the tones would have been heard.

Operation

This is a half duplex radio, i.e. you need to release the PTT switch in order to hear a reply from another station.  Do not press the PTT when another station is transmitting as this will cause interference.

At the 2.4 GHz operating frequency the antenna height above ground is the key factor that determines the range.

The microphone is a noise canceling type so it needs to be positioned so that it touches your lips, not off a inch or more.

Antenna

The radio is designed to be worn on the non shooting shoulder and placed so that the antenna is above the top of the shoulder, thus giving it a good field of view.  This is why the audio cord on the headset is much shorter than those on older larger radios.  The radio uses the very common SMA female panel jack that will mate with SMA male cable ends or the stubby 2.4 GHz antenna.  At 2.4 GHz antenna height above ground has more to do with the range than the RF output power.  The best place would be on top of the helmet of a standing soldier.

I tried to use the higher gain WiFi antenna that's part of the USB-802.11n adapter for the CF-28 Toughbook, but it will not fit the Bowman radio because the O.D. on the SMA (3.0 mm) connector is too large to fit down into the hole on the Bowman radio.

Frequency

Instead of operating in one of the standard military frequency bands this radio operates (2.4 - 2.483) in the 2.4 Ghz Industrial Scientific & Medical  (ISM) bands where no license is needed for secondary users.  This particular band has a Wi-Fi specification, IEEE 802.11, that's commonly used for linking laptops and PDAs to a network.  The 802.11 protocol is used by this radio.  I think that means that no license is required to use this radio in the U.S.  If you know one way or the  other please let me know.

The 16 position channel knob on top of the radio combines with the 16 position rotary switch on the 12 contact face to allow for a total of 256 channels.  No programming of the radio is required.

The top knob is marked with even numbers and dots between them so it can be read as channels 0 to 16 or channels 1 to 15 with no ambiguity.  But redundancy if someone says channel 1 and someone else says channel 16 since they are the same knob position.

Low Probability of Intercept (LPI), Low Probability of Detection (LPD)?

When PTT is first pressed a sequence of tones is heard in the earphone and a WFS-1 Wi-Fi detector shows activity.  But in a few seconds the activity stops (just one radio being used) and the side tone in the headphone no longer matches the spoken voice.  I think this means that the radio was unable to link to another radio and has quit transmitting.  It appears that no linking occurs until the PTT is pressed, which is a good way of doing it.  That way you are not carrying around a beacon to let others know you are around.

At about 100 feet the WFS-1 is still has one LED on so the actual range is probably much more.  The output power is specified as 50 mW.  This means that there's a 100% chance of detection at 100 Feet and maybe longer ranges depending on what's between the transmitting PRR and the WFS-1 Wi-Fi detector.

Carry Pouch

The snap that secures the narrow bungie cords over the top of the radio has a projection that's the tool needed to set the Group number 16 position switch when the PTT is removed.  But how do you loosen the screw holding the PTT to the radio?

The SELEX marked radio does not have the small screwdriver for setting the internal channel group switch.

DC Power

Instead of using a military battery it uses a couple of the very common "AA" batteries that are available about anywhere in the world.  The down side to that is most AA batteries do not work at or near freezing temperatures.  Is there a provision for external DC power to the radio? This would be good for retransmission use.

There may be a reverse connected diode across the battery contacts so if both batteries are installed backwards they will get very hot but the radio will be protected.  A better way is to use a FET switch (see Analog Troubleshooting by Bob A. Pease of National Semi).

DC power can be supplied to the AUX radio connector and then the two AA batteries can be removed from the radio.  This is for the Clansman aux PTT module and might also be the case for the U-229 AUX PTT.

Audio Connection

LEMO  I think the 5 pin headset plug is the FGG.1B.305.KLAD62.  This plug supports: Ground, Mike input, Headphone output and retransmission.  For retransmission all that's needed is a special cable to interconnect the two radios (this is very similar to the PRC-68 family and other mil radios).

Lemo has a USA site.  A mating receptacle might be the EGG.1B.305.KLL (rear nut) or EEG.1B.305.KLL (front nut)
A strain relief for the headset plug might be the FFM.1B.130.LC nut plus GMA.1B  strain sleeve (both of which are not on the stock headset plug but should be.)

The audio connection is on the PTT switch pack, not on the radio proper.  So the 12 contacts on the side carry the aduio connections.

There is a collett on the back of the LEMO connector that needs to match the diameter of the cable.  So when making up LEMO plugs you need to know your cable diameter prior to ordering the connectors.  I'm working on making an audio test box for the 5 pin connector.  I have a query into Belden, but it's being delayed by the Thanksgiving holidays.

Headset

The headset has a single ear piece and attached to it are the 20" cord that connects to the radio and the mike on a flexible boom.  The ear piece has open holes surrounding the speaker element so that you can also hear any ambient sounds.  The mike is of the noise canceling type and so needs to be placed so it touches your lips.  Is is worn with the speaker on the left ear.

Data Connection

One of the PTT switch packs supports data by means of a connector on the attached cable end.  But I now think the Dual PTT U-229 connector also supports data coms.  The sales brochure implies low data rates, not 802.11 Wi-Fi rates.  There's a cable to connect the data port to a PDA.  If you know about this please let me know.  I'm guessing that it's the standard U-229 Data protocol.

There may be a special cable to interface to a Personal Digital Assistant (PDA).

The Bowman radio can be connected to a PLGR or DAGR GPS receiver using the data interface.  A simple application of this would be to send your position either in absolute coordinates or relative to some bulseye location.  A more advanced application would involve sending target or close air support data messages.

Push To Talk

Instead of just using a common PTT switch there are a number of innovative options.  The PTT module screws onto the narrow left side of the radio making contact with a 3x4 (12 ) contacts array.  There are a number of tone signals that let the radio operator know some key status situations.  These can be turned off by holding PTT while turning on the radio.  See above for the tones.

The PTT modules are:

• Single PTT button switch pack
• Dual PTT button switch pack with cable for second radio.  The UK Dual uses the 7 pin Clansman connector and the NATO version uses the 6 pin U-229 type connector commonly for use with the PRC-148 MBITR but would work with about any radio like SINCGARS (RT-1439) radios.
  
• Data Interface Single button switch pack - supports combined voice and data although at low speeds (PDA cable?)
  
• Wireless PTT switch - this is a small switch that can be affixed to the forearm of a rifle or anywhere that it would be convenient to have a PTT switch.  It has it's own 3.6 V lithium battery that should last more than 10 years.  433 MHz 128 bit operation. 
  
  To affiliate a WPTT power up the radio with the WPTT positioned so that the word "PROGRAM" on the WPPT is on the hump between the two buttons on the DUAL PTT.  The magnet in the DUAL PTT tells the radio to look for a signal (like programming a rolling code garage door opener).
  You should hear the first ascending stair step tone.
  Now press and hold the WPTT botton until you hear the second ascending stair step tone.  The radio and WPTT are now affiliated and will be until you undo the affiliation.
  
  To remove the affiliation:
  Turn the radio off and position the WPTT as described above for affiliation,
  Turn on the radio and hear the ascending stair step tone indicating there's a WPTT affiliated, do NOT press the WPTT but instead:
  Move the WPTT  a foot or so from the radio to open the magnetic sensor on the radio and return it to the radio 5 times and do all that within 5 seconds of turning the radio on.  If done properly you will hear a second ascending stair step tone and after powering down the radio when it's turned on you will hear the three dot power on tones.
  

NSNs

NSN	Prod #	Description
5820-99-721-8335	P21050000	PRR Body (Green) Complete – English The PRR body  is complete with an antenna and an English user card. Must be used with single or dual push-to-talk (PTT) switch assembly. Requires two AA batteries (included). Infantry use (500m range)
5820-99-739-4033	P08130000	Single PTT Switch Assembly (Green) The single PTT switch assembly is for use with the PRR body.
5820-99-342-4097	P08120000	Remote Wireless PTT (Green)The wireless PTT remotely operates the PRR. Supplied with a black adjustable strap and buckle.
5820-99-127-2911	?	Dual PTT with 7 pin Clansman cable connector Dual NATO PTT From Derk: Using with Kenwood amateur radios PRR wire signal Kenwood connection black PTT M/3 green microphone M/2 yellow earth m/3 blue speaker m/1 For kenwood connection: 1=tip, 2=middle, 3=base and M=mini and m=micro jack
5820-01-531-1752		AN/PRC-343 personal role radio set with: Radio P21250100 5820-99-721-8355 Single     PTT P08130000 5820-99-739-4033 Wireless PTT P08120000 5820-99-342-4097 Daylight Headset P0814490008  5965-01-533-3341 Boom Mike Adapter P07120000 NSN? Carry Pouch P30180100  5895-99-991-3095
5820-01-531-1758 (see DPRR below)	P21050041	AN/PRC-343 personal role radio set with: Radio P210501000  5820-99-721-8335 Dual PTT P08140341  5820-99-666-0452 (<-???, see below) Wireless PTT P08120000  5820-99-342-4097 Daylight Headset P09255+0009 NSN??? Boom Mike Adapter P07120000 NSN? Carry Pouch P30180100  5895-99-991-3095
?	?	Single PTT with (detachable?) PDA cable
5820-99-280-7276	P14360408	CT/Light Patrol Headset (Green) – Noise-Canceling (NC) Electret Microphone The vented, single-sided headset has an NC Electret microphone fitted to a flexible boom arm. Fitted with an adjustable headband, the headset can be worn underneath most passive ear defenders.
5965-01-533-3341	P14490008	CT/Light Patrol Headset (Green) – Noise-Canceling (NC) Electret Microphone The vented, single-sided headset has an NC Electret microphone fitted to a flexible boom arm. Fitted with an adjustable headband, the headset can be worn underneath most passive ear defenders and balistics helmets.
5965-99-664-9722	P07100000	Nuclear, Biological, or Chemical (NBC) Boom Microphone Adapter The adapter is for use with most Davies headset models. One end fits over theheadset’s boom microphone and the other end plugs into the respirator’s speech module.  See patent 7493899 below
5820-99-425-3999	C410114	Carry Pouch (Green) – United Kingdom (UK) Pattern Disruptive Pattern Material (DPM) The PRR fits inside a heavy-duty polyurethane, textured nylon pouch that attaches to webbing and helps protect the PRR from harsh conditions/impact.
5895-99-991-3095		Carry Pouch (Green) - U.S. Molle
5985-99-664-9730		Antenna
5820-01-533-3406		Battery Door The two doors shown are aftermarket made by Dragondark.
5820-01-533-3652		Strap & Buckle for Wireless PTT
5820-99-666-0452

12 Contact Radio interface

Oct 2011 - newer pinout info from Eero: H4855 module connector 

This 12 contact field contains the signals needed for the headset (mike, speaker and PTT) , for data coms (Tx data, Rx data and maybe Tx clock and Rx clock), for retransmission (PTT and Squelch) and probably some test modes and external DC power.  If you have info please let me know.

Summary:

1	2	3	4	5	6	7	8	9	10	11	12
Mike	PTT	Spkr	+Vout	Gnd	PTT				RxD	TxD	PTTsel

It sure would make it easier to have a pair of working radios.
Looking at the connector the top row (nearest the on-Vol control) is numbered left to right 1, 2, 3, 4 and the center row 5, 6, 7 ,8 and the bottom row 9, 10, 11 & 12.
First probing Voltage all combinations with the radio turned off.
Black test lead on Fluke 87 DMM for left coulmn and Red test leat for top row.

B R-> V

1 M

2 P

3 S

4

5 G

6

7

8

9

10

11

12

1 mike

x

2 PTT

x

x

3 Spkr

x

x

x

4

x

x

x

x

5 Gnd

x

x

x

x

x

.044

6

x

x

x

x

x

x

.044

7

x

x

x

x

x

x

x

.044

8

x

x

x

x

x

x

x

x

.044

9

x

x

x

x

x

x

x

x

x

10

x

x

x

x

x

x

x

x

x

x

11

x

x

x

x

x

x

x

x

x

x

x

12

x

x

x

x

x

x

x

x

x

x

x

x

x - no point in testing the same thing two times or the same contact.

Now probing with the On-Vol at full volume:

B R-> V

1 Mik

2 PTT

3 Spk

4

5 Gnd Bat -

6

7

8

9

10

11

12

1 Mike

X

.040

0.3

cap

2 PTT

X

X

.054

.051.

.050

.051

.052

.05

.05

cap

3 Spkr

X

X

X

2.2

.77

2.0

1.96

cap

1.9.

1.8

1.8

cap

4

X

X

X

X

-2.968

-.01

-2.915

-2.967

5 Bat- GND

X

X

X

X

X

+2.594

.05

+2.963

+2.938

+2.963

6

X

X

X

X

X

X

-.006

-2.907

-2.959

7

X

X

X

X

X

X

X

-2.901

8

X

X

X

X

X

X

X

X

+2.910

+2.885

+2.91

-.048

9

X

X

X

X

X

X

X

X

X

-2.962

10

X

X

X

X

X

X

X

X

X

X

-2.936

11

X

X

X

X

X

X

X

X

X

X

X

-2.962

12

X

X

X

X

X

X

X

X

X

X

X

X

Note that a voltage of 2.9xxx volts is the full battery voltage from 2 Alkaline batteries or after a FET type switch.

Single PTT interface

Radio On max vol
Radio Audio Connector numbered 1 to 5 clockwise looking into the PTT jack with 1 at the notch.
The headset only has the noise canceling mike and earphone (no PTT switch)
The PTT button is between contact numbers 2 & 5
Ohms LEMO connector to 12 contacts

B R-> V	1 Mike	2 Gnd	3 Gnd	4 Spkr	5 ?
1 Mike	0
2 PTT
3 Spkr				0
4
5  Gnd		0	0
6
7
8
9
10
11
12

The opened Dual PTT is marked:
D40014201, H204485601, Patent Pending.
It the cut cable has 6 wires (plus ground) colored blue, green, red, yellow, black and a white wire wrapped with bare wire (coax).

	From an Airsoft web page, but I think they have it close but there's more to it.  For example the Blue wire seems to be the true ground. Black: Gnd (PTT) PTT: White (PTT) Speaker+: Orange Speaker-: Blue Mike: Green Mike (power?): Red
	The green & white wires are shielded. The white RTV is surrounding the reed switch that's under the hump between the two PTT buttons. There are 12 SMT caps at the top right of the top PCB (next to the notch in the flex circuit) and the center ends of all of them connect to the blue (gnd) wire.
	Blue dots are connected to the blue PTT cord wire (looks like ground).  Red dot connected to red PTT cord wire. IC is marked LM293
	Blue dots are connected to the blue PTT cord wire (looks like ground). Top IC is marked HC02A Bottom IC is marked HC14A The three 5 lead SOT-23 packages are marked "AAA".
	Blue dots are connected to the blue PTT cord wire (looks like ground). The IC on the back of the 12 contact PCB is marked MAX4167.

DPTT Interconnection Table

2nd Radio Cable (PCB order)	Radio I/F
Black		?
Blue	6, 8	DC Gnd & Speaker Return
Yellow (orange)		Speaker Audio
Red		Mike DC power
White (shielded)		2nd Radio PTT
Green (shielded)		Mike Audio
	3	top (Radio) PTT

These are what's called push on pull off.  No rotation of the connector is needed to install or remove the plug.

Headset Interface

Shown above is the 5 pin LEMO headset connector.  In normal operation this connector only carries mike and speaker audio.  But when the retransmission cable is connected it also needs to carry a PTT signal to key the radio and a squelch signal.  In the U-229 type connector this takes a total of 6 wires.  So it's still a mystry how the retransmission works using only the 5 pin connector.  Most likley pin 5 carries a digital signal as a bus.  For example by using a pull up resistor the line is held high and when squelch closes (a signal is being received) that radio puls the line low, but that's just a guess.

The H4855U has a red mark on the LEMO connector and I'm assuming it's pin # 1.

Dual Personal Role Radio Set

Got this from Mike Murphy (8 Apr 2010) new in the box. 

The inner box is marked:
5820-01-531-1758
CAGE 37EK0
PN  P21060041
DUAL PERDONAL ROLE RADIO SET
1 EA
SPM7A3-07-F-0002
GS35F0348S
M31-7/07

Contents 5 palstic bags:

	SELEX Radio Set 5820-01-531-1758 Radio 5820-99-721-8335 Dual PTT (H204485601, D40883601) w/GC329 connector attached, Antenna, two AA cells, card marked "Integrated Squad Radio Operator's Guide card marked Integrated Intra Squad Radio Fitting of Reppirator Adaptor & Tube
	Headset (P1449008)  NSN 5965-01-533-3341
Wireless PTT	Remote PTT (5820-99-342-4097, P0812000)  (bag marked use by 01/01/17
	Bowman Wireless PTT spectrum HP 4395A 433 MHz Tx frequency
	Universal Carry Pouch - ALICE or Molle
	Gas Mask Adapter
Dual Personal Role Radio Internal Channel Switch set to Channel 0

H4855U "Paint Ball" Replica Radio

Note that this radio is marked H4855U, i.e. it's a UHF radio.
At the time of purchase I thought this was a "Replica" Bowman radio used for Paint Ball gaming.  But when received, it's looks like a real UHF frequency Bowman radio Set.  There's a small chance it's a replica with ham radio internal circuitry.  When searching the NSNs printed on the various parts, none of them show up on Google, so maybe it's a replica?

It operates on 16 channels in the 440 MHz band.  Behind the Single PTT module there are two DIP switches instead of the 16 position rotary switch that's on the 2.4 GHz H4855 radios.

I tried to use the radio with a couple of Alkaline AA cells, but it's not working.  The supplied batteries are 14500 size Li-Ion cells (3.6 Volts nominal, 900 mAh) and came with a charger.  This radio needs the higher voltage it will NOT work with Alkaline AA batteries, that seems strange, was it a mistake or what?

When the radio it turned on you hear "Open to Radio xx" where xx is the channel number.  The headset is interchangable with the other Bowman headsets.

The data sheet shows a programming cable in the first column forth down connecting the radio LEMO connector to a laptop (USB or Serial?).

H4855U Set
H4855U Max Hold Spectrum from chan 1 and chan 16 (made with HP 4395A)	The display spectrum correlates with the data sheet that shows 440.050 for Chan 1 and 440.800 for chan 16 (i.e. 50 kHz chan spacing).  This was done with the two DIP switched off.
	H4588U Radio 5820-99-721-7655 Mod Record: 1, 4, 16 Single PTT 5820-99-127-0957 Have not tested to see if it works with a real radio, but suspect that it will.
	Headset 5965-99-280-7276 This has a real LEMO connector and is form, fit and function interchangable with the real headset.
	Wireless PTT 5820-99-342-4097 DIP switch #2 (under the single PTT) turns on or off the wireless PTT.  There does not seem to be an affiliate function like on the 2.4 Ghz radios.  But PROGRAM appears on the unit, strange. Works on a different frequency than the real wireless PTT and so will NOT work with a real radio.
	The wireless PTT operates at 315 Mhz not the 433 MHz that's used for the 2.4 Ghz radios.  That's probably to seperate the PTT frequency from the radio frequency.
Set #2 came without batteries and charger so can not be powered up until I get a couple of the special batteries (3.6 V 900 hAh).
	Kenwood stock programming cable The hope is to modify this cable to work with the H4855U.
	Kenwood stock programming cable Plug The hope is to identify the function of the plug contacts then after cutting the plugs off link the function to wire colors.
Kenwood Interface	Kenwood TH-F6 Data Interface pinout from the owner's manual page 45. It's probable that the data interface for programming is the same. The programming cable only has three wires: Red, Black and White. This is my best guess asto how to make a programming cable. Pgm Cable Dual Plug LEMO Radio 12 term Function Red DCD In 1 4 Mike Black Gnd 2, 3 9 Gnd White PTT 4 8 Spkr na ? 5 - ? Note: there are pull up resistors to +3.5 V on the DCD and PTT lines.  Myabe in the 1k to 3.3k Ohm range. The wiring is based on cutting a cable sold on eBay as a Kenwood programming cable, i.e. that's why the wire color and DCD, Gnd & PTT connections.

This is a setup used in the UK to integrate the Bowman radio into their vehicle audio system similar to our VIC system.

Clansman/PRR Switch Box

	The red rectangular component is a power supply. marked: Traco Power In: 9-36 V Out: 3.3V 900 ma Ten 4-2410 The silver rectasngular component is an Eisen audio transformer marked: A262A7E Audio Tel (01993)886200 The box is a Hammond 1590-NI
	On the bottom of the PCB there are a bunch of 1 uF caps and an 8 lead IC marked: 33171  PZGL which is a low power Op Amp
	The Traco Power module supplies +3.3 V to power the radio. The Transformer is wired: Winding Switch=PRR Switch=Other A1 PLA-B A2 10 uF to A3 A3 10 uF to A2 A4 PLA-A B1 90 Ohms to Gnd B2=B3 B4 Gnd

The black box has the following Controls, Indicators and Connectors.

		Cable Box - end		Connector - end
Label		Cable Labels	Cable Wires	Conn	Conn - Pins
CLANS/PRR	(Other/CLANSman)/PRR			3PDT switch 9 white wires
PLA	7 male pin cir conn (capped)		A: B: C: D: E: F: G: lemo-2	GB 62GB-57A10-7PE 5 white wires
PLB	2 male pin conn DC Supply	ska & DC Power		GB 62GB 51T10-2PC TCX note 1 2 pins Brown Blue	A: +24V B: Gnd
SKC	2 female scokets DC to Vehicle Radio	DC Supply & +28V		GB 62GB56T10-2SC TCX note 1 2 sockets Brown Blue	A: +24V B: Gnd
Harness Output	HO LEMO jack (same as on radio) LEMO p/n: HMG.1B	936-155/01 - harness output	1: 2: PLA-G 3: 4: Gnd 5:	[PU]APH 0613 62GB-56T10-07SE 7 sockets flex circuit	A: B: C: D: E: PLA-E F: G: PLA-G
na	attached cable - LEMO plug (radio Audio) 936-1540/01			(red dot on shell) red blue yellow green white black	1 2: Gnd 3: Gnd 4: 5 6: nc
na	attached cable - small 6 pin LEMO to Vech PTT module (PS) 936-1541/01 Note 2				red blue

note 1: these two connectors mate with each other.  This appears to be a daisy chain DC power system similar to the VIC DC system.
Note 2: the small 6 pin LEMO connector does not fit the PSG-9 Message Terminal external Power jack J2. But the core of this plug does fit J2.  What is the correct LEMO plug for J2, let me know.

Documents

Pocket Card - Vehicle Fit Personal Role Radio (PRR) Operator's Guide 739-0042/01 Issue 2 Jul 05

Operation with US VIC Equipment

In order to do this requires figuring out:
The pin out of the 7 pin 56T10-07SE connector as well as the polarity of the DC input connector.  The signal levels may or may not be compatible with the VIC system.
It would be good to know the wiring of the Vech PTT module and the input voltage levels (probably 3.3 VDC from the Traco DC-DC module, i.e. 2 AA Batteries)  that it accepts.

The rebroadcst unit is configured in a saddlebag arrangement with a radio system in each of the two bags and with an interconnecting cable.  The interconnecting cable carries digital Tx and digital Rx audio, not analog audio.  Although the details are not really clear RF filters are used, one passes channels 1 to 4 and the other passes channels 13 to 16 (channels 5 through 12 are not used providing for the filter skirts).  Any group number can be used.  It would seem that one of the saddle bags would be for the low channel numbers and the other for the high channel numbers.  The filters have a little less than 3 dB attenuation in their pass bands.

There are "switch packs" which may be in the form of PTT units that connect to stock radios.  The LEMO connector on the switch packs are interconnected with a cross over cable the interconnects the Tx digital audio of one ratio to the Rx digital audio input of the other radio.

There are a number of surplus radios being sold by the MOD in the UK.  These have been stripped of the knobs antenna and PTT switch and maybe even the battery compartment door, i.e. just a very raw radio.  They probably do not work and being sealed have been rejected rather than repaired.  It's probable that you could saw them open and with a number of them make one good radio.

Coming shortly.  For now you can use the above tables of resistnace and voltage.

1. The part line is clearly visable.  The two case halves are glued toghther, but not by fusing the plastic.  So using a few light blows from a 2.5 pound Dead Blow Hammer (Harbor Freight 33905) a "crack" is heard then with a screw driver the lid can be seperated from the main radio body.  DO NOT hit or set the radio on the PTT interface during this process as that will damage the interface PCB (guess how I know this).
2. Disconnect the connector then remove the RF can top lid.
3. Bend the 4 tabs to allow the digital board to be lifted.  Note there are two holes in the board that can be used to lift it.
4. Use a 5/16" socket or nut driver with an OD less than 0.447".  The 5/16" Craftsman deep 1/4" drive socket (set 934421) has an OD of 0.445'.  This unit has double sided tape on the bottom of the can, but it was not sticking.  You may need to use pliers to pull the can up after taking off the nut and lock washer.  Remove the RF shield can bottom lid.  The RF board is soldered to the shield can.
5. The remaining chassis contains the battery contacts, flex circiut and plug ans well as the two switches.

1. Lid Removed	2. Connector lifted & Shield removed. Lines to tabs.	3. Tabs bent & Digital board top removed from radio	4. Remove SMA nut &  can from chassis
4. Top of RF board	4. Bottom of RF board	3. Digital board bottom	5. Box & flex ckt w/ switches

Atmel AT90S8515 - 8 bit Micro Controller w/ 8K bytes of flash memory, 32 IO lines, 44 pin TQFP
AMI WavePlex 0034LQM SX043T - ?
WavePlex 0108LDH SX061T - ?
CML CMX639E2 43265 - CVSD Digital Voice Codec
4168 EUB - Maxim High-Output-Drive, Precision, Low-Power, Single-Supply, Rail-to-Rail I/O Op Amps with Shutdown (speaker driver)
HC74  E1052 - ?
EM09AB LMV824  MT - Shantou stars Electronics Co Ltd   SOP-20 - ?
DS1844 100 9939A1 134AA - Maxium Quad Digital Pot 100k Ohm
P12AF LCX125 - 14 pins - Low Voltage Quad Buffer with 5V Tolerant Inputs and Outputs
P14AJ LCX257 - 16 pins - Low Voltage Quad 2-Input Multiplexer with 5V Tolerant Inputs and Outputs
P14AJ LCX257 - 16 pins - Low Voltage Quad 2-Input Multiplexer with 5V Tolerant Inputs and Outputs
MAX1705  EEE  0124 - high-efficiency, low-noise, step-up DC-DC converters with an auxiliary linear-regulator output (3v in - 5V out)
LMV822 -  NSC Low Voltage, Low Power, RRO, 5 MHz Dual Op Amps

AMP Fine Pitch SMT Stacking Connectors (Parallel Board-to-Board) 0.8 mm pitch

2x30 connector - Digital board to Chassis via flex circuit (many grounds)
2x20 connector Digital board to Analog board.

Right Angle SMA-f on Analog board