[ARC5] CBY-46104 Receiver - Command Set Navigators

[Mike Morrow]

>I presume the 1.5 to 3 Mc model was used for communication rather than
>navigation.

The AN/ARC-5 manuals for the near equivalent R-25/ARC-5 1.5 to 3.0 mc receiver defines it and the R-26 3.0 to 6.0 mc and R-27 6.0 to 9.1 mc receivers as communications receivers, while the R-23 .19 to .55 mc and R-24 .52 to 1.5 mc receivers are defined as navigation receivers.

The R-23 could most obviously serve as a beacon band receiver, and even without a loop antenna it would be especially useful stateside on the large network of directional Adcock A-N beacons spread across the USA.  The R-23 was also potentially an Airtrack(tm)-system instrument landing system (ILS) localizer receiver when equiped with a MX-19/ARC-5 audio adapter in the front, connected to an AN/ARN-9 (or ZA or ZAX) ILS system.  Unlike the "communications" AN/ARC-5 receivers which have *no* audio brought to the adapter box, a special filtered AF signal is brought out from the cathode of the 12A6 AF amp to the adapter box for use with this ILS.  Fortunately, that old pre-WWII Airtrack ILS was quickly displaced by the USAAF's far superior SCS-51 system (AN/ARN-5 and BC-733/RC-103), basically the same ILS in use today, 65 years later!

Like the CBY-46145/ARA and the BC-946-B, the R-24 broadcast band receiver was apparently mainly intended to serve with the AN/ARR-1 (or ZB or ZBX) 246 mc homing adapter, since all R-24 (and ARA and BC-946-B) units came with the MX-20/ARC-5 (or CBY-62036 or FT-310-A) power adapter for the R-1/ARR-1.  The AN/ARR-2 displaced the need for the R-24 for that purpose, but the R-24 was also wired to support use with the Airtrack ILS just like the R-23.

The R-23 and R-24 also have loop connections and switch, presumably for the DU loop, but I'd bet that they were almost never used in that manner.  The RAV equivalents (CBY-46102, CBY-46103) also have the same loop accomodations, while the ARA (CBY-46129, CBY-46145) and SCR-274-N (BC-453-B, BC-946-B) equivalents do not.

I am unaware of any purpose-intended navigation function that the R-25 could have performed, or its earlier ARA/RAV/CBY-46104 predecessors.

Mike / KK5F