>Just received some interesting paper today.
>It appears that our illustrious Ameritron-MFJ engineer is using Rich's
>ideas in the new Ameritron AL-572 amp ( four 572B's).
>
>The schematic indicates the grids are NOT grounded as we have been led to
>believe is the "best way". Instead they use 1000pf caps and 51 Ohm
>resistors to ground for each tube.
>
>Gee Whiz; Golly Gee.... maybe Collins, Heathkit and Rich were right after
>all; or at least on the right track ????
>
>73 Carl KM1H
>
OTOH, maybe they are ALL on the wrong track, and the self-declared
'expert' in Georgia is right?
- Seriously, I don't believe that a G-G amplifier becomes substantively
more VHF-stable with some of the intrinsic grid L being tuned out with a
series capacitor to ground. IMO, better stability happens in the anode
circuit by lowering VHF-Rp / VHF-Q.
- The 51 ohm resistor in the grid current path Might be useful as a
fusing device for a 572B or 811A- provided it is a 1/2 watt carbon film
type.
Rich---
R. L. Measures, 805-386-3734, AG6K
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