ORIGINAL MESSAGE:
On Mon, 22 Mar 2010 14:54:33 -0400, "David J Windisch"
<davidjw@cinci.rr.com> wrote:
>
>Replacing the choke with p/n RFC-3 from rfparts.com, and putting the bypass
>right at the cold end, made several differences in circuit operation. The
>tank setting for max-power-out, Ip-min, and Ig-max on 15M and up coincide, and
>there is more power out on 12M. My guess is that the choke and resistor were
>dissipating significant r-f power.
REPLY:
Glad you got it working, David.
I have used that RFC-3 choke in five different homebrew amps so far
and I am quite impressed with it. Designing a choke that will cover
all ham bands from 1.8 to 30 MHz including WARC with no resonances is
not easy, as even the commercial amp makers have found out.
A word of caution to anyone who might try to copy the RFC-3: Be sure
you get the same wire diameter, the same type of insulation and the
same insulation thickness. Change any one or more of those and you
have a different choke.
The usual disclaimers apply - no connection to RF Parts except as a
satisfied customer.
73, Bill W6WRT
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