[Milsurplus] Receiver Filter Adaptor- Diagram Correction

[David Stinson]

Arden- All:
Sorry to take a while to reply.  Work presses.

I made an error in the "in situ" diagram (Me?  Make an ERROR? 
Say it ain't so!).  Here is the corrected V1 plate circuit 
showing the in-rig screen bypass, C226B (a plate bypass when 
using the adaptor), in the proper place  (don't forget to hit 
"reload" to clear the old diagram out of your browser cache):
http://home.netcom.com/~arc5/TCS/AdaptorInSitu1.jpg

Here are the original TCS IF stages for reference:
http://home.netcom.com/~arc5/TCS/TCSIF.jpg

R215 is the screen resistor which becomes a plate dropper when 
using the adaptor.  It's not what you would want in V1's plate 
circuit, but "the rules of the road" say it is fixed and 
immuteable, so must be accepted.  Any substantial change in R215 
and one could no longer replace the adaptor with the original 
12SK7.  Fortunately, the V1 stage seems to work well as-is and I 
like that there are only 4 mils of current in that filter primary 
winding.   I may do some more fiddling to see if I can't get the 
DC off the filter, shunt-feeding V1, but I risk running afoul of 
the "Law of Pernicious Parts Count" and it's "Sam Rayburn 
Corollary."

There do seem to be some issues with V2 at only 20 plate Volts. 
I'm going to try the suggestion of one of our kind and "smart 
people," bringing the plate back up to 120 volts and setting 
stage gain with the cathode resistor.   A question for our "smart 
people" (assuming anyone is still reading at this point): 
Should I bypass the new cathode resistor, or is there some 
benefit from leaving some degeneration in there?

Happy weekend, everyone.
GL OM ES 73 DE Dave AB5S

P.S. I was asked why I was posting this to the "ARC-5" list since 
it isn't an "ARC-5" receiver.  I do because some people there 
believe what we're discussing has applications in just about any 
old receiver and they asked me to do so.  "DEL" button works 
great, guys ;-)