[Milsurplus] Looking for unobtanium

[Nick England]

It looks like the interconnection schematic (figure 5-8) has an error - it
shows one of the relay contacts connected to 115ac input. BUT the other
contact is shown going to +20 carrier on the exciter - this is wrong wrong
wrong! Someone got confused when drawing a line on this schematic.

The correct wiring is shown in the AC power distribution schematic (figure
5-10). The AM-3007 power transformer is energized when the relay is
energized.
The relay is energized by +28vdc from the exciter in standby or operate.

Nick England K4NYW
Chapel Hill NC
www.navy-radio.com


On Fri, Oct 3, 2025 at 3:08 PM Reuben Popp <reuben.popp at gmail.com> wrote:

> Apologies if this comes out of thread..
>
> Thank you all, I truly appreciate it.  Still on the hunt, unless I can
> convince Nick or Brown to relinquish theirs ;).
>
> I THINK the "uncommon" things I would need to source to build one would be
> the two filters in assembly A6 and the relay.  That said, I'm trying to
> follow the latter's path and understand what exactly it does when
> energized.
> Correct me if I'm wrong, but it seems:
>
> 1. AC comes in via the box, traverses the filters in A6 and then enters
> the amplifier.
> 2. AC comes out of the amplifier on pins R and S of the 41 position
> connector
>    - S supplies common to all connected units
>    - R supplies 115 to both the transmitter and receiver as well as the
> "left" side of the relay.  Someone please educate me here if there's better
> nomenclature here.
> 3. This is where I begin to get lost.  I ASSume that when 28V is applied
> to pin M of the transmitter, that energizes the coil of the relay, making
> the circuit and applying 20V to pin T of the amplifier for the carrier.
>
> Bear with me here a moment.  My understanding of relays is that the coil
> has a minimum voltage requirement to make the circuit.  I ASSume here
> that's at least(?) 20V?  If pin T is expecting 20V for the carrier, then
> if/when the relay makes, wouldn't that effectively be 28V from its input?
>
> On Thu, Oct 2, 2025 at 4:22 PM Reuben Popp <reuben.popp at gmail.com> wrote:
>
>> Hey all,
>>
>> I come seeking some help from those of you who have been into collecting
>> and rebuilding these radios for far longer than I.  I am, short of an
>> exciter parts unit, short one piece from having most of an AN/WRC-1 system
>> to rebuild.  That's the exciter, the receiver, the amplifier, the antenna
>> tuner, and the handset.  What I am missing is the interconnect box
>> (NSN 5895-00-973-1063).  Last year one was quoted to me from a logistics
>> supply house for 24K.  YEOW!  There's pay to play and then there's where'd
>> my kidney, spleen and lung go?
>>
>> Anyway.. I look all the time  trying to find one.. any time I head to the
>> hamfest, or on ebay, craigslist, you name it.. no dice.  Columbia
>> Electronics doesn't have one, Murphy's told me maybe if I had asked about
>> 30 years ago, and Surplus Sales of Nebraska said we won't know until it
>> gets unburied (if it exists) in the warehouse.
>>
>> So, my question to you is, in your time of having done this, how have you
>> gotten over this hurdle?  The TM has the specs for the box.. at least the
>> dimensions of it, so I could have one made, or fab it myself.. of course
>> that also means having to try and source another set of connectors for the
>> cabling in/out as well as building its innards.  At this point of waiting,
>> I'm beginning to think this is my only real chance of finding one, unless
>> one of you happen to have one squirred away, lol.
>>
>> Any suggestions?  Thanks, and 73
>> Reuben
>>
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