[MRCA] RA-10 ( ) receivers & Bendix misc.

[Mike Morrow]

Larry wrote:

>There are some differences in the receivers as well as their purposes. 
>A couple were 14V (RA-10CA & RA-10CB) and a couple were used for 
>Direction finding (RA-10DA & RA-10DB - 28V)

The RA-10CA (14 vdc) and the RA-10DA (28 vdc) were identical except for input voltage.

The RA-10CB (14 vdc) and the RA-10DB (28 vdc) were identical except for input voltage.

The CB and DB models came from the factory with circuitry and connections for the loop (MN-20 or -24) and loop bearing indicator control box (MN-52).

The CA and DA models did not have this loop support circuitry, but it could be easily added.

IIRC, the plain RA-10C and RA-10D units were identical to the CA and DA models, except that these had two parallel AF output channels.  The CA and DA (and CB and DB) models eliminated the redundant AF tube and transformer, though these also could be backfitted.

Bendix unit model designations, especially those letters following the number, are anything but consistent and logical.  They are downright confusing!  For example, there are two control boxes for these receivers, the MR-9B and the MR-9C.  The B model is used when the associated receiver is connected for low impedance AF output, while the C model is for high impedance AF.  The control box AF potentiometer was different in these two applications.

Mike / KK5F