[ARC5] BC-946

[Mike Morrow]

There is only one real reason for the late introduction of the BC-946-B receiver to the SCR-274-N.  It was to support operation of the R-1/ARR-1 VHF (246 MHz) "ZB" Homing Adapter.  R-1/ARR-1 is the JAN nomenclature that was assigned to the USN's ZB-2 or -3 Homing Adapter.  Some R-1/ARR-1 adapters have name plates with USN contract numbers and others with Signal Corps Contract numbers.

The USN's version of this broadcast receiver is the R-24/ARC-5, intended for use with the AN/ARR-1 homing adapter or  potentially as MF Localizer receiver for the USN's AN/ARN-9 Air-Trak ILS (abandoned by 1944 in favor of the USAAF's superior ILS AN/ARN-5 UHF Glide Slope Receiver and RC-103-A VHF Localizer Receiver.)

With appropriate inter-connector wiring the AN/ARR-1 may be connected and used with the BC-946-B without need of the AN/ARR-1 control box or antenna switch.

The AN/ARR-1 was installed on some B-29 bombers, but its BCB output was fed to an AN/ARN-7 ADF receiver instead of a BC-946-B.

In fact, it is unlikely that the SCR-274-N and AN/ARC-5 sets were ever actually used with the AN/ARR-1.  The R-4*/ARR-2 Homing Receiver fit in AN/ARC-5 racks and eliminated need for both the R-24/ARC-5 and the R-1/ARR-1.  That's why surplused inventory of these items have almost always  been new unused condition.  OTOH, the USN's earlier ARA broadcast band receiver CBY- and CCT-46145 plus ZB-2 or -3 VHF Homing Adapters stand a good chance of having actually served in ARA/ATA command sets on carrier-based aircraft prior to introduction of the later AN/ARR-2 in AN/ARC-5 receiver racks.

Mike / KK5F

-----Original Message-----
From: <ranickels at gmail.com>
Sent: Mar 5, 2024 6:44 PM
To: ARC-5 QTH <ARC5 at mailman.qth.net>
Subject: [ARC5] BC-946

I was fortunate to have picked up this gem from a recent estate sale:


Never had one before and haven't even seen more than a couple.   I'm curious - what external equipment might have been powered from the FT-310-A adapter?
I can rob one off another receiver, but are there any good DIY alternatives for a local tuning knob (unless someone has a spare MC-237 burning a hole in their drawer ;-))
73, Bob W9RAN



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