This is for those of you who are NOT purists when it comes to your
amp.I had an FL2100B to work on and I made a mod. to monitor the grid
current , since there is no grid metering in that amp. I installed a 2.5
mm stereo jack on the back panel over the input ckts. Then I installed a
1.5 ohm resistor in the grid lead, just like the SB200 . I connected the
two ends of the resistor to the stereo jack's two ungrounded terminals ,
connected a 200uamp meter to a stereo plug and plugged into the jack,
and "VOILA" the amp now has grid metering.The owner of the amp is happy
with the setup.!!!!
If you happen to be a purist then this isn't for you , but I
believe it could easily prevent losing some expensive tubes due to
excessive grid current when tuning up.!!!
carl / kz5ca
P.S. I also use a 'pulser' for tuning up, on cw, it's
easier on the tubes. my final step is to hit the key and make sure the
grid current is where it should be, under 90 mils.for two 572B/T160L's.
I managed to find several of these tubes.!!! not cheap , but they are
the best in my mind.!!!
Have a good day all.!!!
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