[ARC5] ATC-1 and T-47/ART-13

[Mike Morrow]

>A pair of ART-13/ATCs, item # 150246615761

These are both very nice examples of USN units.  The associated description, as expected, is inaccurate in places.  Both units, apparently surplused to some airline, are former USN units.  The T-47/ART-13 was a Navy unit, not Army, and thus would not have served on B-29 aircraft.  The NXsa and NXss numbers are incorrectly cited as serial numbers rather than Navy contract numbers.  The US Army used instead the improved T-47A/ART-13.  I guess I'm too picky.

>Very interesting. Does anyone know if the tuning book would
>have been shipped along with the set? I don't see it.

I once saw a "still in original crate" T-47A/ART-13 about 15 years ago that had the tuning book present (just one data point).  The T-47A/ART-13 is a USAAF unit that usually has the book attached by rubber-covered metal lanyard to the transmitter, unlike the loose books on USN units.

There are three major variations of the tuning books.  Although sometimes done, there was no point to serializing tuning books to the transmitter.  The data is identical for all ATC, ATC-1, and T-47/ART-13 units with the later type of CFI unit installed.  ATC and ATC-1 units that have the early type of CFI unit also have identical tuning books, but different calibration points are marked.  The tuning books of all USN units provide data for tuning intervals as small as 1 kc at the low end and as large as 10 kc at the high end of VFO range.  The thicker tuning book for the USAAF's T-47A/ART-13 provides tuning data at 1 kc intervals throughout the entire VFO range.  It can do that because the HF VFO dial of the T-47A has a vernier scale that USN units lack.  If you are searching for a tuning book for your unit, it would be best to locate the book appropriate for your unit.  They are a lot harder to find than is the transmitter, but at least the common pdf versions of the operating and maintenance manuals contain the needed tables.

Mike / KK5F