[Amps] Tube swap

[William Turner]

One way I have done this is to remove the suppressor and replace it with 
a straight wire. Then take a grid dip meter and couple it tightly to the 
wire you just installed and look for the dip. NO POWER TO THE AMP OF 
COURSE. The dip will be very  narrow and very deep, a sure sign of high 
Q. Then install the VHF suppressor, the values of which are not as 
critical as some people think, and look for the dip again. Now the dip 
should be gone without a trace, not even a tiny wiggle. If you do see a 
wiggle, try different combinations of L and R. As a rule, 50 ohms for 
the resistor is a good place to start and the L should be the largest 
value that will NOT burn up the resistor on the highest frequency the 
map will operate at. IOW, if the resistor smokes on ten meters, reduce 
the value of L and try again.

And above all, as someone else mentioned, do NOT use carbon composition 
resistors. The change value over time and either direction of change 
will cause major trouble eventually.

73, Bill W6WRT

On 1/28/2014 2:53 PM, Karel wrote:
> I just have to figure out what the factory design should be. I will 
> definitely use ceramic resistor. Any suggested lead to better 
> suppressor setup?
> Values, arrangement? Thanks,
> Karel, VA3KO