[Heathkit] foldback

Mon, 06 Oct 2003 17:37:48 -0400

This is Rich Measures' site.  There is a wealth of information on the
SB-220.
http://www.somis.org/sb220ci.html

The SB-220 was designed when most exciters were tube based with a pi-network
output.  The pi net output is able to match a wide range of loads and the
input impedance of the amplifier was not a serious design consideration.
Many Solid state exciters are not as forgiving and some attention to the
amplifier input impedance is necessary.

Jim

----- Original Message ----- 
From: "Hotmail" <[email protected]>
To: <[email protected]>
Sent: Sunday, October 05, 2003 12:10
Subject: [Heathkit] foldback

> I have a great SB220 with the latest Harbauch mods that I installed.
>
> Question:
>
> My exciter (TS140S) folds back to 50 watts out on 10 meters. How do I go
about tuning the amplifier (input circuit I guess) to eliminate the foldback
issue or is this normal?
>
> Thank you,
>
> Bruce
>
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