[Amps] Re: Thunderbolt

2 2@vc.net
Sat, 11 Jan 2003 09:51:20 -0800

>Around here Bill, KC2IFR (iirc) just put one on the air - AM, 75m.
>One of the things he found was that the input is a 350 ohm resistor...
>which makes matching to solid state trancievers a bit dodgy... He ended
>up using a matchbox between his rig and the Johnson...
>He says he tried changing it to just a 50 ohm resistor and it did not
>"work"... seems like it should have, but I wasn't there.

A 200-ohm grid terminator fed through a 1 to 4 bifilar transformer should 
work ok with c. 100w drive.
>His choke was shorted out - he put a different choke in the hole...
>It sounds pretty good so far on AM... but he says he'd rather have
>a different linear knowing what he knows now...
The original circuit can be improved.  There is no such thing as a 
perfect commercially mfg amplifier.

-  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,