[ARC5] Command Set Navigators

[Mike Morrow]

Jay wrote:

>In this case for the R-1/ARR-1,wouldn't the BC-946-B and the R-1 be 
>"fixed tuned"?Then wouldn't the three rx control box that has only two 
>tune cranks and two dials and only the sense and cw/mcw knobs for the 
>third receiver be used?(I don't recall the BC-* number).

Jay

That sounds like a cross between one of the rare SCR-274-N HF/VHF receiver control boxes, or a similar version in the AN/ARC-5 system, and the C-38/ARC-5 that had a control box for the AN/ARR-2 (not AN/ARR-1) built in.  There was no SCR-274-N control box that had specialized controls for the AN/ARR-1, because the receiver to be controlled was a BCB BC-946 very similar to the other receivers in the standard installation.  The standard BC-450-A control box already had all the controls needed.

It is likely that the SCR-274-N system was almost always in a standard three-receiver, two-transmitter configuration, with a standard three-receiver control box in the pilot's compartment.  As I outlined in my earlier posting, the AN/ARR-1 could be put into use by simply removing the BC-453 beacon band receiver, installing the BC-946 in its place, and connecting the power and RF cables from the AN/ARR-1 to the BC-946.  The R-1/ARR-1 would be fix-tuned and locked, but the BC-946 could be tuned by the pilot to the desired BCB modulating frequency as necessary.  If in the future it became desirable to restore beacon band coverage, it would only take minutes to restore the BC-453 to the rack.

The AN/ARR-1 (or ZB/YG) homing system could utilize different BCB frequencies modulated on the 246 MC carrier.  In order to use the correct one, the pilot has to tune the BC-946 to the appropriate frequency.  Being tunable allows the pilot to select several different BCB modulating frequencies.  Being able to quickly select any of six pre-set BCB channels on the 246 MC carrier frequency was one of the big improvements of the later AN/ARR-2 over the AN/ARR-1, and explains why AN/ARR-2 control boxes don't have a BCB frequency dial on them.  The AN/ARR-1 has the same capability, but the pilot must manually tune the BC-946 to the desired modulating frequency.  Fix-tuning the BC-946 would be unnecessarily limiting to use of this homing system.

No special control boxes or other troublesome issues would have to be resolved to install or remove the AN/ARR-1 homing system on the standard SCR-274-N set.

Mike / KK5F