[Milsurplus] So what is a : CU-32 for an ART-13A

[Mike Morrow]

>Any one  have I idea what this is worth :CU-32  tuning unit for an 
>ART-13A?

This must be it:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140363155273

It's the best of the AN/ART-13 LF/MF external antenna units, although
it's about the same size as the T-47A itself.

The schematic of the CU-32/ART-13A is shown in the upper left corner
of the complete AN/ART-13A schematic that Mike Hanz has at:

http://aafradio.org/docs/ART-13A_schematic.png

It's a combination of LF/MF external PA tank circuit, RF current meter,
and antenna switch (fixed vs. trailing wire).  It covers 200 to 600
kHz.  It was originally a USAAF AN/ARC-8 (AN/ART-13A, AN/ARR-11 [BC-348])
unit, but the USN ordered and used some CU-32 units for their AN/ARC-25
(AN/ART-13, AN/ARR-15) system too.

The receiver's antenna circuit in these systems does not pass through
the LF/MF tuning network.  The AN/ART-13A would need the O-17/ART-13A
installed.  If one had the USN's O-16/ART-13 (200 to 1500 kHz), the
CU-32 is not designed for that full range.  Given the frequencies
covered, unless one were participating in some of the 600 meter MF
ham experiments, there would likely be little ham competition for one
except for parts.

Still, the CU-32 is not all that common anymore, and the MT-198/ART-13
mounting (not part of this auction, apparently) is even less so.  Anyone
trying to put together a full-house USAF AN/ARC-8A would need these.

I think I paid about $100 for each of the two that I have, but that was
years ago and they didn't come from ebay.  The $150 start price doesn't
seem too bad to me.

BTW, Mike's AN/ART-13A schematic referenced above is an outstanding copy
that is much better than the same circuit found in most original AN/ART-13A
manuals.  Somewhere in the manual revision process, the schematic got
corrupted and a number of lines and connections are missing, mis-spaced,
or not clearly connected in later revisions of the AN/ART-13A tech manuals.
Most reproductions of these manuals have the same problems.  Mike's copy
must have come from an early original manual that had not been corrupted.
Thanks, Mike!

Mike / KK5F