[ARC5] Receiver Filter Adaptor- Evolving Backwards

[J Mcvey]

Dave,
Did you "scope" the plate of V2 during the overload? Maybe the zener is the culpret, causing too much drop and clipping? I assume it's there because the the supply exceeds the 135V plate voltage? 
How about replacing the zener with a coupling cap and supply the plate with a hi-Z choke from the "screen" supply? The only issue might be how much current is available from the screen circuit? Maybe put a zener to ground at the screen pin  to stabilize the voltage a bit?
 

    On Tuesday, February 16, 2016 11:34 PM, David Stinson <arc5 at ix.netcom.com> wrote:
 

 It won't surprise some of you that I'm having trouble with the 
triode design for the filter adaptor.  It just can't handle 
strong signals like during a CW contest.  Guess I should have 
expected it since the 6026 is designed to be an oscillator.  I 
just happened to find a bunch of them.  It sounded so good on a 
quiet band.  But tonight, things ain't so quiet and trouble came 
knocking.
http://home.netcom.com/~arc5/TCS/TCSFilterAdaptor1.jpg

Soooo.... I'm evolving back toward the pentode design Collins 
intended.  One of our members recommended compatable pentode 
sub-minis so I'm going to get those and work back towards the 
original:
http://home.netcom.com/~arc5/FilterAdaptor/

Oh well... Even Babe Ruth struck out 1400 times so I'm in good 
company.
73 Dave AB5S

P.S. I did try shunt feeding V1 and using a .001 to couple to the 
input of the filter, but this introduced a lot of loss.  Probably 
because the plate potential is so low to start with, series feed 
is the only way to get any signal through the filter primary.


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