[Milsurplus] Signal Corps History - The Green Books - ART-13 cal books

[Mike Morrow]

Ken wrote:

> ...I am looking to trade for one, possibly two, ART-13 calibration
> booklets, the ones that tuck into the slot (with the sleeving-covered
> chain, if possible)?

There are *at least* four different "ART-13" calibration books, for:

(1)  USN ATC, ATC-1 with 8Q-1 CFI (calibration) unit,
(2)  USN ATC, ATC-1 with 8Q-2 CFI (calibration) unit,
(3)  USN T-47/ART-13 with 8Q-2 CFI (calibration) unit,
(4)  USAAF T-47A/ART-13.

The first three books are for USN units, which seldom (if ever) have
a vernier scale above VFO dial B.

The last book is for the USAF/USAAF T-47A/ART-13, which should have
the 8Q-2 CFI unit, and a vernier scale above VFO dial B to allow
much greater precision in VFO dial setting.  This allows the T-47A
to be set in 1 kHz increments throughout its full tuning range.  Its
cal book provides data at that interval.  The USN units have setting
data mainly in 5, then 10 kHz increments.  Their calibration books
are much thinner than the book for the T-47A.

I've seen the rubber-covered attachment chain only on USAF T-47A
units.  The USN units that I've seen didn't even have the attachment
hole for the transmitter end of the chain drilled into the side
of the holder slot.

A few ATC books appear to have been serialized to a particular
transmitter.  That was pointless since the cal data are the same
for all transmitters with the same type CFI unit and setting interval,
following adjustment to the local CFI cal point.  (Even the data in
the book for the R-807 Soviet copy are pretty *close* to the U.S.
original.)

About ten years ago, Fair Radio had original (used) books for both
the T-47 and the T-47A.  I was lucky enough to purchase one of each 
($30 each, IIRC) before the supply was quickly exhausted.  That was the
only time in 40 years of collecting that I've ever seen a supply
of such books on sale.  I got my ATC book on ebay.

These books are a lot harder to find than are the transmitters.

Mike / KK5F