[Johnson] Johnson Valiant doorknob cap

[Rodger]

Hi Joe,

I assume you are running into low output/tuning issues on 160 because if 
you don't use the Valiant on 160 the 500pf coupling/blocking cap is 
sufficient.  Hopefully someone on the list will have a 1200pf ceramic 
for you; I wanted to caution you about the 1200pf  red "ceramite" 
doorknobs that you can find at Fair Radio.  Although these would seem 
fine for the task at 1200pf and 5 kv rating I tried using one of these 
as an additional fixed capacitor in an antenna tuner and at 200 watts 
carrier out the tuned swr began drifting after about 10 seconds and the 
antenna only presented about a 2.5 to 1 mismatch to start with.  
Apparently the "ceramite" units don't like much RF current, I replaced 
it with a more common tan ceramic doorknob and no more problems.  I 
tried two different ceramites thinking that the first one might be bad 
but they both behaved the same way.  This unit might hold up OK in the 
Valiant but I wouldn't bet on it.

73, Rodger WQ9E

Joe Roth wrote:
>    I need to change my doorknob cap (C37) on my Valiant from the current
>        500pf value to 1200pf (20Kv). Can someone recommend a source?
>                                     TNX
>                                   Joe-WC4R
>                                 www.wc4r.com
>                               www.rothweb.net
>                            www.williamsburgwx.com
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