[Milsurplus] ART-13

[Mike Morrow]

Mike wrote:

>I guess I've never seen an ART-13B /without/ that switch.  I've had a 
>half dozen here at one time or another with the CDA-T, all with the 
>switch, and all with a nameplate to the right of the switch that sez 
>"Low Frequency Extended Range."  It introduces a small cap into the 
>doubler stage to allow for crystals down to 1.7MHz or so, IIRC.

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.  Maybe it's a case of a T-47A modified with the CDA-T remaining a T-47A, versus a T-47A with the CDA-T and LF Extended Range Switch becoming a T-412.

I've seen several examples of Navy ATC and T-47 units that were upgraded to T-47A standards, presumably by the Air Force.  Those could then become T-412 units.

>http://aafradio.org/flightdeck/b29.htm - about 1/4 way down the page 

Mike, what is the function of the switch on the panel blank for the LF oscillator on your ATC?

73,
Mike / KK5F