[ARC5] ARC-5 and SCR-274-N IF Transformers

[D. Platt]

As if everyone hasn't seen enough on this subject already... Ted, W3PWW 
and I have been kibitzing on the phone and comparing schematics, 
mechanical drawings, and such and appear to have determined that, 
indeed, the Navy used dual-tapped transformers in the 2nd and 3rd IFs.  
Also, according late manuals, there may also be differences for sets 
manufactured after 1945.  It may be well that each set should retain its 
original transformers, although as I mentioned yesterday, I know I've 
crossed over with no noted issues.  Now.. on another tack, I said I 
thought one could probably modify the 40 meter (6.9.1 MHz) receivers in 
the same manner as the 80 meters receivers.  Looks like that's not the 
case.  Looking at the various mechanical drawings, the SCR-274-N 
receivers appear to have a one-piece coil form, and are not eligible for 
the mod, as written.  The Navy units, on the other hand, look like they 
still have the split coils and ceramic spacers.  Ted's having a look at 
his 40 meter receivers to see what's the real story.  The thing is, why 
would the manufacturers use a different methodology for the two 
services?  Makes no sense, to me.  If anyone else has any info, it would 
be good to know what you've found out.  At least the 80 meter rigs are 
good to go.

Jeep - K3HVG