[MRCA] [MMRCG] Univac Aircraft Antenna Coupler

[mstangelo at comcast.net]

Scott,

Thanks for the information. Are either of you using this type of tuner?

I believe they came straight from the depot.

Mike N2MS


> On 01/18/2026 1:10 PM EST Scott Johnson via groups.io <scottjohnson1=cox.net at groups.io> wrote:
> 
>  
> Jim Whartenby is the resident expert on these couplers, but it is P/O the ARC-65 SSB transceiver used on the B-52 and KC-135 until they were fitted with the ARC-190.  That transition happened in the 1980s, so it is likely that coupler never saw service after it was serviced. Both Jim and I have ARC-65s and ARC-21s (the AM version which was modified for SSB to become the ARC-65 in the late fifties).
> 
> Regards,
> Scott W7SVJ
> 
> -----Original Message-----
> From: mrca-bounces at mailman.qth.net <mrca-bounces at mailman.qth.net> On Behalf Of Michael St. Angelo via MRCA
> Sent: Sunday, January 18, 2026 10:53 AM
> To: mrca at mailman.qth.net; milsurplus at mailman.qth.net; MMRCG at groups.io
> Subject: [MRCA] Univac Aircraft Antenna Coupler
> 
> Going through some military stuff on a snowy Sunday and found a couple of aircraft antenna couplers I got surplus years ago. They were designed by ERA and this model was built by Univac. The are an HF Coupler mounted in the vertical stabilizer of a plane such as a KC-135 to tune the probe HF antenna. They were hermetically sealed and basically consist of a rotary inductor and vacuum variable capacitor tuned via a discriminator circuit. 
> 
> I've attached a couple of pictures. The discriminator section has the cover removed. They were last services at Warner Robbins in 1965. I was told they require 28 VDC and 100 AC 400 Hz. The RF connection is made via a C connector (my favorite RF connector)
> 
> I was going to use the components in a tuner but want to get in operational in their original state. Does anyone have any documentation about the tuner or it's controller box?
> 
> Thanks in Advance,
> 
> Mike N2MS
> 
> 
> 
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