Re: RF power chain mods and improvements..

ajparent1/KB1GMX
 

makes sense to reuse parts where possible.

My experience with output transformers is more ferrite the better.
However the 2:4 turn transformers at 12-13V had very poor efficiency 
as in under 40% and a lot of heating and the linearity was also poor.
Didn't make any difference which device.

Note I  measure the current to the finals alone since the board provides
the separate feed.  As a result anything over 2A for 10W was deemed 
not good (under 50%) and with the 2:3 and 2:4 I was seeing typically
2.6to 3A again for only 10W out.   Going from 43 to 61 ferrite made little
difference if the ferrite was enough except at 80m.   A transmission
line transformer 1:1 hooked in with DC blocking caps (.1uf 100V)  as
a balanced to unbalanced was  remarkably good on a BN43-6802 at 10W.
Most cases of ferrite heating it was the wire or how it was wound had
a greater effect.

Allison

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