[Lowfer] A bit of a problem with trimmer caps

Fri, 7 Feb 2003 00:13:32 -0600

100pf should be fine. My 500pf moves the resonant point a long ways. I
forgot how far but there is plenty of QSY room. I never did buy a vacuum
variable as I have been working on manufacturing some car parts this winter,
so the money has been going that way. I will run the pipe cap on 136kc, as
it will handle the current well.

Mike>WE0H
http://www.we0h.us/lf

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of The loop & cap master himself>Bill Ashlock
Sent: Thursday, February 06, 2003 11:45 PM
To: [email protected]
Subject: RE: [Lowfer] A bit of a problem with trimmer caps

Mike,

>So back to the drawing board huh???

Well, more like 'back to the capacitor pile'. At the moment I'm thinking I
might give this 100pf air variable a try. That's all the variability I need
to tune from from -3db to -3db points, once the capacity range is centered
using medium sized capacitors (and this can be accomplished with a
temporarily-installed trimmer).

>I think I will go back to finishing the copper pipe variable cap then
> >since it appears at this point that the air variable caps could be a
> >problem whether it is a big sucker like my Johnson cap

What's wrong with that vacuum variable as long as you connect a wire to
bypass the sliding contact? BTW this jumper wire idea will work on any air
variable as long as a small plastic stop is installed to allow only 180 deg
rotation.

>or the small trimmers. Just when you think it is all figured out Murphy
>steps on your toes.

Wouldn't call this Murphy as much as just plain learning about the effects
of the environment these high Q circuits have to live in.

Bill

PS: Just got both loops working without any interaction between them. In a
few minutes I'll be modifying one of my Basic programs to allow the
sequencing. Let the snow begin!