[ARC5] Any difference in the front plugin pin out on CCT-46104

Sat Sep 9 12:58:23 EDT 2017

I have three 1.6 - 3.0 Mc/s receivers; one CBY-46104 and two R-25/ARC-5.

I used to have one I used as a fixed IF for a Morrow 5BR-1 mobile converter for a main station receiver in late 1950s.  That one got pitched (unfortunately) after house destroyed in a tornado in 1999.

73 de Mac, K2GKK/5
(Since 30 Nov '53)
Oklahoma City, OK
USAF Retired 61-81
FAA Retired 94-10

________________________________
From: arc5-bounces at mailman.qth.net <arc5-bounces at mailman.qth.net> on behalf of J Mcvey via ARC5 <arc5 at mailman.qth.net>
Sent: Friday, September 8, 2017 20:49
To: WA5CAB at cs.com; arc5 at mailman.qth.net
Subject: Re: [ARC5] Any difference in the front plugin pin out on CCT-46104

Ok , thanks for the info. This is the second ARA I've ever come across. Are they rare? 1943 mfr date.
You never know what you might find  done to these radios!

On Friday, September 8, 2017 8:19 PM, WA5CAB--- via ARC5 <arc5 at mailman.qth.net> wrote:

The CBY- and CCT-46104 covers 1.5-3.0 MC and are from the ARA set.  There is no SCR-274-N Equivalent as the AAF didn't buy any.  R-25/ARC-5 is equivalent.  However, all of the ARA and SCR-274-N receivers have substantially the same circuits except for varying component values in the different frequency receivers.  The exception is that the audio output impedance of the ARA receivers is around 500 ohms.  The A-models of the SCR-274-N are 4000 ohms.  And the B-models can be connected for either 4000 or 250 ohms.

The ARA and SCR-274-N receivers all have a rudimentary AGC system sensitive only to signals whose amplitude is sufficient to drive the 2nd IF tube into drawing grid current.  The AN/ARC-5 receivers have a more conventional AGC system except that the diode rectifier is in the 12SF7 2nd IF tube.  But in any case, nothing to do with either system connects to the front connector.  So if the 2nd switch was supposed to turn off the AGC, it was a mod.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480

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