[ARC5] arc-5 BCB RX seen

[Mike Morrow]

>> Looks like a pile of junk to me with the exception of the power PI unit
>> for connecting to the LM-xx.
>
>The power connector would more likely go to a ZB homing receiver since
>it was used with the 46145 receiver (along with others.)  Actually, I
>can't recall an installation where it was used to power an LM, though
>it certainly could ... and I'm sure (and hope) someone can point one
>out to me.

I suspect that the old tale about those power adapters being used for the LM frequency meter is mostly just supposition.  

Only (but always) the BCB receivers CBY-46145, BC-946-B, and R-24/ARC-5 were issued with this power adapter.  There is little evidence that *many* of these BCB receivers ever saw actual service, so there is little likelihood that there would be a receiver in the command set rack that had this adapter unless it was separately obtained and installed in another more commonly used receiver.  Had this been a common requirement, one suspects that the beacon band receivers would have been issued with the power adapter.  But just how likely would in-flight precision frequency adjustment of the command set gear be required?  Never, I think.

The only real purpose of the BCB receiver was to replace the beacon band receiver CBY-46129, BC-453-B, or R-23/ARC-5 in the standard rack and be connected to a ZB-series, R-1/ARR-1 (Signal Corps contract), or R-1/ARR-1 (Navy contract) VHF homing adapter.

The "classic" receivers that used the ZB were the RU-series and the ARB, but the RU requires all those additional ZB control and relay boxes that are not used when the ZB is attached to ARA or ARB receivers.  I believe that the CBY-46145 saw some use with the ZB, and also that the USAAF in the PTO may have used the BC-946-B with the R-1/ARR-1 as required.  I'd be really surprised if anyone ever turns up evidence of the R-24/ARC-5 having been used with the R-1/ARR-1.  About the time it came out, so did the R-4/ARR-2, an all-in-one VHF homing receiver that fit the same rack as the R-24/ARC-5 and had significant additional versatility.

I'd love to find some testimony about actual USAAF use of the BC-946-B and R-1/ARR-1.  It seems like such a simple and useful navigation system to add to USAAF aircraft having to traverse hundreds of mile of featureless ocean in the PTO.  But such use appears to have been rarely documented.

Mike / KK5F