[Lowfer] Re: Amplifiers for 136k

[Bill Ashlock]

John A,

>This particular circuit seems to work into a wide variety of load 
> >impedances, based on what I saw on the bench before putting it outside.

Yes, the circuit (including filter) certainly does work into a wide variety 
of load impedances as my Pspice modeling indicated. I believe if you had 
tried to connect it to a load via a 100ft coax you would have seen large 
ringing at the transmitter and a large DC input current to the stage.

> > This all leads back to my original thoughts last week on the
> >simplicity of using a two transistor switching PA out in the woods >at 
>the base of the loop for the 136k, 100w application. Adding a
> >core with four or five turns and mica cap is no burden at all!

>Not sure that I follow that description. Add some words please!

If I build a simple 100w two-transistor final using the same design as my 
present 1w woods final but with beefier transistors the only add-ons to 
greatly reduce the harmonic content of the loop signal would be a ferrite 
core with 5 turns and a mica capacitor.

Bill A



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