[MRCA] Zenith Radio ART-13?

[D. Platt]

Correct me if I'm wrong, here.  Both my ATC and my ART-13 were upgraded 
at some point to have the vernier dials.  My late-model Navy ART-13 
(yep... T-47/ART-13) has the 3-tube CFI-MCW module in it.  The "A" model 
calibration book, as stated, is arguably twice as thick owing to the 
additional settings.  That said, either book works with either unit, 
with the caveat that the accuracy is superior with the "A" model book.   
Also, an additional indicator of who made the unit is that Collins units 
have their logo molded into the chassis casting in the area of the audio 
and CFI-MCW modules. Both mine have it........

Question is, do only S/W units come with the 3-tube CFI-MCW module? Were 
these modules used universally later on?  I know the A-model had an 
interlock installed and the vernier, of course, and perhaps the T/R 
relay assy. but what else is there?  Looking at the late-issue AFTO that 
covers all three variants,  I'm still trying to see material 
differences.  Can you all shed some more light on the subject?

Jeep - K3HVG


The T-47A/ART-13 has all these improvements, plus a dynamotor DC control 
power interlock to top cover removal, plus a vernier scale on MF/HF VFO 
dial B that allows the VFO to be set at one-tenth of a minor dial scale 
division. Thus, the calibration book for the T-47A is tabulated for 
MF/HF VFO settings at 1 kHz increments throughout its entire operating 
range. The earlier transmitters are calibrated for only 5 kHz increments 
up to 8 MHz, and for only 10 kHz increments when higher than 8 MHz. The 
T-47A cal book is thus about twice as thick as one for an earlier model. 
So...IMHO Collins did *not* make the best version of this transmitter 
system. That honor goes to Stewart-Warner Corporation's T-47A/ART-13. 
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