[Milsurplus] ART-13

[Mike Morrow]

I wrote of the LF EXTENDED RANGE switch:

>The switch is shown in all pictures of the T-412/ART-13B in T.O. 12R2-2ART13-2,
>30MAR56.  But earlier AN/ART-13 manuals (pre-AN/ART-13B era) cover T-47A
>units with the CDA-T mod that retained the T-47A ID.   I don't recall that the
>LF EXTENDED RANGE SWITCH was on those units.

I found another T.O. 12R2-2ART13-1, 12DEC56, that covers the AN/ART-13B.  But there's *no* T-412 info in the manual.  Instead, page 1-2A dated 27AUG52, has a photo showing "Radio Transmitter T-47A with Oscillator CDA-T installed," and text in the manual refers to this combo as an AN/ART-13B.  There is *no* LF EXTENDED RANGE switch in this photo, and there is no mention of MF operation between 1670 to 2000 kc, which that switch and crystals in the CDA-T allowed.

Thus, it appears that the AN/ART-13B has two variants:

(1)  T-47A/ART-13 with CDA-T [no LF EXTENDED RANGE switch] (early model)
(2)  T-412/ART-13B [with CDA-T and LF EXTENDED RANGE switch] (later model)

Mike / KK5F