Radio Distribution Box does not conform to Circuit Diagram Where does Plug 3 go to?

[SirLanceUK]

As everyone knows I have a Spartan that i have been slowly working through trying to get most systems working, if not as the Army intended then fit for purpose.

I have been working in the back getting a working Intercom and nor trying to get a working Radio, hence why I am asking questions about the Radio Distribution Box.

Now on the circuit Diagram i have the   RDU, Gen Panel, Dist Panel and Relay Box are all just "blank" boxes, they had the inputs ad outputs but not what the levels are, or what the levels might be.

However that is not the question, On Socket 3 and 4 of the RDC (24 volt 4 pin socket) that is nothing connected, but in my RDC socket 3 had a 4 pin plug in it, which disappears in to the loom and in towards the front of the Spartan. I have buzzed through all the 4 pin plugs and sockets I can find any yet nothing seems to buzz through the cable that goes in to Socket 3 of the RDC.

The only thing left for me to do now is undo the wiring loom and chase the cable to see where it goes, BUT before I do that I thought I would ask on here to see if anyone actually knew where I could find the other end. It's not at the Dist Panel or the Relay Box.

 

 

[sirhc]

[Chris Suslowicz]

I know nothing about Armour, but that looks like a "bare vehicle" fit - the Radio Distribution Box has two 4-way connectors and an 'outline' Radio Junction Box in socket 2 (nothing in Socket 3). So it's most likely a way of showing the power distribution to a single set (socket 2) or two-set (sockets 2 & 3) installation. 

The real details will be provided in the Communications Installation EMER for the actual setup.

Best regards,

Chris.

[Chris Suslowicz]

Afterthought: The cable in Socket 3 probably surfaces wherever the second radio is/was meant to be fitted. It may have been tucked away out of sight and tied down to prevent rattling, as it well have a 4-way free socket on the end, intended to mate with the power distribution box for the second radio set. That could well have been mounted on the "top tray" for the second set. it just depends what was fitted:  C42 and something else (if Larkspur era) VRC353 and maybe VRC321 if Clansman. (There was also a Doppler radar observation system, so the socket may have ended up somewhere completely different if it was meant to power that!)

Best regards,

Chris.

[SirLanceUK]

14 hours ago, sirhc said:

Brilliant, that explains a lot and I know where to look, I did look there before but I am guessing I didn't check properly. Once again SirHC saves my bacon 

[SirLanceUK]

10 hours ago, Chris Suslowicz said:

Afterthought: The cable in Socket 3 probably surfaces wherever the second radio is/was meant to be fitted. It may have been tucked away out of sight and tied down to prevent rattling, as it well have a 4-way free socket on the end, intended to mate with the power distribution box for the second radio set. That could well have been mounted on the "top tray" for the second set. it just depends what was fitted:  C42 and something else (if Larkspur era) VRC353 and maybe VRC321 if Clansman. (There was also a Doppler radar observation system, so the socket may have ended up somewhere completely different if it was meant to power that!)

Best regards,

Chris.

Thanks for the response Chris, I think SirHC's diagram explains where I need do be looking. It also explains what the RDC box actually does, but I appreciate people who take the time to answer questions.

[Chris Suslowicz]

I've since discovered that I bought a binder full of CVR(T) documentation[1] from a friend who was moving house and downsizing... this included User Handbooks for various vehicles, CES lists for ancillaries, and does include the Spartan.

A quick browse tells me the radio fit (Clansman) is VRC-353, PRC-352, Intercom, plus CBF (Commander's Box (Fixed)), and I think the CES for the radio fit lists all the cabling, trays, etc.

If this is any use to you I can run it through the scanner. (It does not appear to have actual layout diagrams for the radio install, for that you probably do need the EMER Comm Inst for the particular setup, but Dom Blanchard may be able to provide whatever that turned into (AESP something_or_other).)   

Best regards,

Chris.

[1] There are several boxes of manuals, including binders for CVR(T), CVR(W), Chieftain Mks 1 to 15 (I think), Saracen & FV432 plus other non-radio related stuff (Radar and Fire Control Equipment) Tentage, Bridging, Armour Training, and Lord knows what else!

[Chris Suslowicz]

Thinking about it, the Intercom is probably always going to be required, so cabling for that may be incorporated into the standard vehicle harness. (Other possibilities are the ECC (Emergency Crew Communication) for Commander to Driver which originally used a "Power Microphone" and used the vehicle battery and a transformer rather than an amplifier to feed the intercom circuit - the big grey Tannoy or Truvox microphones with the 3-pin connector.)

Chris.

[SirLanceUK]

On 1/6/2024 at 11:30 AM, Chris Suslowicz said:

Thinking about it, the Intercom is probably always going to be required, so cabling for that may be incorporated into the standard vehicle harness. (Other possibilities are the ECC (Emergency Crew Communication) for Commander to Driver which originally used a "Power Microphone" and used the vehicle battery and a transformer rather than an amplifier to feed the intercom circuit - the big grey Tannoy or Truvox microphones with the 3-pin connector.)

Chris.

Hi Chris,

Thanks for getting back to me and thanks for the offer of documentation. I must admit I have a few manuals here already but for some reason I often can't see the wood for the trees. In this case it was SirHC's diagram that showed me what was what, however your last comment made perfect sense as I have had a working Intercom for some while without the need of the rear batteries, but my circuit diagram shows no such power lead for the intercom.

Lance