[Amps] Commander-2000 issues

[Roger]

Bob KD7YZ wrote:
> Hello. I have a, new to me, Commander-2000. I can tune it up for, say,
> 1400 watts with key-down and maintain that output on SSB or CW
> throughout a QSO.
>
> New to also is JT65A/ FSK441 for Meteor Scatter and EME. So I tried my
> tune up method nd got into a sked with Jarda the other day on 6m.
> Initially I was putting out 1400 watts. After a very few sequences I was
> putting out 800 watts ... then 500 ... then I called it all off.
>
> After a while, as _you_ all understand, and I don't,  the Amp worked
> just Peachy-Keene. And it still does.
>
> So, obviously I need some "learning" or I need to make some mods to it
> to handle the workload of JT65 on EME . Well, I tried a MS sked with
> Bill today and started qt 1400w out to my 6M8GJ and after a few FSK441
> sequences, I was down to 800 .. you get the picture.
>   

The manual should have the tuning sequence they prefer, but with 
grounded grid amps it's normally just tune for max out while keeping the 
drive low enough to not exceed the maximum grid current. If max out is 
exceeding 1500 watts, reduce the drive and repeak.

You apparently have something heating but it may not be in the amp. It 
could be at/in the antenna, feed line, or connectors. It could even be 
in the AC wiring. You are running the amp on 240VAC? and good heavy wire?
with a good plug and socket?

Often it's the simple things we all tend to overlook.

73 and good luck,

Roger (K8RI)
> Bill suggested I join this list. Here I am ...
>
> --
> bob kd7yz EM88ii
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