[Milsurplus] Tubes used in URC-4 ?? New addendum

[Mike Morrow]

Alan wrote:

> Maybe not in the URC-4 (unless there was an RT-159B?), but IIRC,
> later portables used the 6397 in place of the 6147, just like the 6050
> replaced the 5676.

That's true, beginning in fact with late "B" models (which I think were in
service by 1956).  The T.O. says that for RT-159B/URC-4 units after serial
number about 16000, the CK 6397 replaced the USAF 6147, and the JAN 5678
replaced the 2E32.

That's a pretty complicated number of variations in tube line ups for a
simple eight-tube rescue radio that came out in 1950.  Maybe the best line
up to use to restore any tubeless URC-4 would be that used in the late B
models.

73,
Mike / KK5F