[Milsurplus] ART-13 differences

[WA5CAB at cs.com]

Further to Mikes details, either most or all (don't know the answer to that) 
AN/ART-13 components were originally built as components of ATC or ATC-1.  
They were converted by changing, or in some cases adding, nameplates.  The one 
component that I know was built from scratch after the nomenclature conversion 
is CU-24/ART-13.  Converted ones have a black wrinkle finished base plate and a 
nameplate (on the back side!!!).  Newer ones have plain aluminum base plates 
and the nomenclature is engraved.  But I don't know whether they were built 
under AN/ART-13 or AN/ART-13A contracts since they didn't engrave the contract 
number.

COL-52286 (the ATC transmitter) and T-47/ART-13 originally had a different 
design transmit-receive relay assembly.  The later ones are backwards compatible 
and were no doubt used for replacement in the earlier transmitters.

There was something else that's different but beyond thinking I recall that 
it was in the middle of the transmitter back towards the tube bulkhead, I can't 
recall what it was.  I'd have to go and look at a T-47A and a 52286 or T-47 
side by side over in Storage to jog the memory.

All I have ever seen of the early twin slide mounts are the upper parts that 
are attached to the transmitter.  I have a COL-52286 in Storage that still has 
them.  But not the lower parts that were attached to the aircraft or ship.

In a message dated 10/9/2005 4:11:10 PM Central Daylight Time, 
kk5f at earthlink.net writes: 
> John asked:
> 
> >What is the difference between a T-47/ART-13 and a T-47A/ART-13?
> 
> 
> The main difference between a T-47A/ART-13 (USAAF) and a T-47/ART-13 (USN)
> is that the T-47A has a vernier scale on VFO dial B which the T-47 lacks,
> allowing it to be precisely set to tenths of a dial division.  As a result,
> the calibration book of the T-47A shows VFO dial B data in 1 kc increments
> from 2.0 to 18.1 mc, while the T-47 calibration book only shows VFO dial B
> data in 5 kc increments below 8.0 mc, and in 10 kc increments above that.
> 

Robert Downs - Houston
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MVPA 9480
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