[ARC5] [Milsurplus] ARC-5 or SCR-274-N ID Question

[WA5CAB at cs.com]

John,

I left off the column headers (added below).

Unfortunatately (in this case), the audio transformer, RF choke and Audio 
choke each carry the same A.R.C. part numbers.  At least according to the 
manuals.

The easiest ID'er (of those requiring removal of covers) is pin 8 on the 
2nd IF tube socket.  If it's grounded, the receiver is from AN/ARC-5.  If it 
isn't, then not.  But the 12SF7 has filament on 7 and 8, like the 12SR7.  So 
don't just look for a socket with pin 8 grounded.

In a message dated 10/25/2009 10:32:35 AM Central Standard Time, 
jfor at quik.com writes: 
> Wonderful, Robert.
> 
> Do you have any data on te bigger coil unit on the underside of the
> chassis? Those numbers are easier to see.
> 
> Much appreciated.
> 
> -John
> 
> ==================
> 
> 
> >To answer an earlier question, the RF coil racks have the same A.R.C.
> >number (6220) in both the 46104 and the R-25.  As do the BFO transformers
> >(5854).
> >  But the IF transformers are different.
> >          46104   R-25  
> >1st IF   7271   9681
> >2nd IF   7272   9684
> >3rd IF   7273   ?   (missing from manual)
> >
> >Pin 8 on the 2nd IF Amp socket is grounded in the R-25 and not in the
> >46104.  And pin 4 on the front panel plug is unused in the R-25 and has a
> >wire on
> >it (TEL.) in the 46104.
> >
> 

Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480