[Amps] Drake L4B/8877 Retrofit Problem
Rick Stealey
rstealey at hotmail.com
Mon Dec 10 19:54:49 EST 2007
Ron,
Did you ever try the exercise of putting an approximately 3500 ohm resistor across the tune cap to simulate tube driving Z and looking into the loading cap with an antenna analyzer, looking for 50 ohms?
I am in Calif. right now and unable to do any amp work on my 8877 project but before I had to come here I did that and had good luck. In my case I am merely trying to see if my tank L taps are set right and if my plate tune cap is in the right range. But my point is, I was able to see a nice sharp dip to 50 ohms as I tuned the tank caps. In your case, since all is ok on 20 meters you would have something to compare 80 meters with. Although you obviously wont see breakdown you might find such things as stray resonances, bad bandswitch conductivity, etc.
Might be interesting to try.
In my case I am going to a breadslicer for the tuning cap, took out the vac variable. I ordered some padding caps from "Annas CW Store" on eBay and will experiment with them in a few weeks.
73
Rick K2xt
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