[Milsurplus] Looking for ATD tuning unit

[Mike Morrow]

> I have an ATD 1940 vintage transmitter I bought in 1967. I am looking for the
> tuning unit  #  CRR-47211 , 9050 to 15,800 Kcs

These are as common today as they were in 1967...essentially non-existent, though
I've heard a couple of claims over the past 25 years of a sighting.  I've never
seen one, or even a picture of one.

The CRR-47207 200 to 540 kHz tuning unit seems like it should have been standard
instead of the odd-ball CRR-47208 540 to 1500 kHz tuning unit.  The 47207 is also
not real easy to find, in spite of the associated CRR-47206 200 to 540 kHz external
antenna tuning unit being standard.  I have a CRR-47207, so those do exist.  It even
looks used, but that's probably due to poor storage.  But the CRR-47211 is a whole
higher level of "hard to find".

The RCA ARB receiver frequency coverage essentially matches that of the Bendix ATD.
Those two make a natural pair, along with a ZB-* homing adapter on top of the
ARB and a LM-* CFI, since these sets have no internal method of assuring proper
frequency setting.

The ATD is not one of Bendix's best jobs.  It was a white elephant. 

73,
Mike / KK5F