[Amps] !44Mhz Gi7B amp problems continued

Steve Thompson g8gsq at ic24.net
Sun Aug 21 12:21:01 EDT 2005


Sean Williams wrote:

>Hi All,
>
>I have just finished this amp, built to a YU1AW design.
>
>It used to oscillate at 480 megs, this has now been cured,
>
What was the fix?

> however, it 
>no longer produces anywhere near the power it used to - Previously I 
>could achieve 800 watts for about 40 watts of drive.
>
>Now I struggle to get 150 Watts before the grid current shoots through 
>the roof - anode current never rises above 300 ma at 2.2kv.
>
>  
>
The impedance at the anodes is too high. The coupling between the output 
and the stripline needs to be increased.

Steve


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