>
>My 6M 8877 is operating, but the T-match input only tunes down to 3:1 SWR,
>what is the cathode impeadance I'm looking to match, like the 110 ohms for
>a gg
>4-1000A? I want to try the MFJ 259 trick.
The MFJ (QRP) trick is on you. There is nothing like a g-g cathode
driven at the ratings. For example, the 8877 cathode delivers 3 peak
amperes at the neg-65v crest in drive. 65v/3a = approx. 22 ohms.
However, at the pos-65v crest, the cathode Z is close to infinity. The
avg driving Z is roughly 50-ohms.
. Why do some people fear adjusting the tuned input with 75w drive?.
There are certainly no dangerous voltages on the cathode.
? Keep your hands off of the anode supply and you will not fry.
- For a good match, one needs a Pi tuned input with an XC1 of roughly
25-ohms on each band. .
later, Dick
- Rich..., 805.386.3734, www.vcnet.com/measures.
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