[Amps] gu-84b negative grid current- followup

chuck ka1mwp at comcast.net
Mon Apr 20 09:57:49 PDT 2009


Well, I got to the bottom of the NEGATIVE grid current this weekend..I had
posted a question here asking about
why I was seeing this and was it normal. After more research into this, I
redid all my tank calculations and have come
across with different numbers for the values, I ended up loading fine on my
80m settings with 40m input!
 
I use the MFJ and a 1.5k resistor to ground (tube impedance) and sweep the
tank.
 
I used several calculators to determine my inductance values but they are
all quite different...
 
I think the closest one I have seen was the Eimac charts...
 
I know of the following: Rich Measures info, Eimac, Ian's (GM3SEK)
spreadsheet and one I found this weekend on the
web I think it was tank-something or another.exe LOL
 
anyway..difficult to know output power, its assumed. Difficult to calculate
plate current, I haven't seen good charts yet on the 
GU-84b characteristics..
 
so thanks for all your inputs to my questions, always good to hear different
opinions and experiences from the reflector.
 
 
Chuck - KA1MWP
 
 
 
 
 


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