[Amps] 144 MHz GS35B update

N1BUG paul at n1bug.com
Mon May 1 14:40:37 EDT 2017


I'm seeing more RF output with the new configuration, about 500W for 
somewhere around 25W drive. It appears I am going to have some fun 
getting the input SWR down but I guess everyone does. That's 
probably why there are so many slight variations on coil dimensions 
among the various plans.

My first try with both coils having 5 turns 15mm ID, 20mm long 
resulted in minimum SWR of 3:1. My second try with 4 turns 15mm ID, 
20mm long got it down to about 2.6:1. I am not sure whether to take 
another turn off both coils or perhaps just the one on the tube 
side. Many pictures of amps I have seen appeared to have less L on 
the tube side although I don't see this mentioned in any 
accompanying text.

Paul


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