HW-101 VFO instability: Coil busted?

Jeffrey Weiss weiss at TDS.NET
Tue Nov 17 16:41:48 EST 1998


Hello,

After receiving much good advice I finally totally disassembled my HW-101's VFO
and rebuilt it.

I anchored the big 4700 pf cap to the VFO wall.
Replaced a small 56pf cap with a 47 pf cap per a bulletin suggesting that the
trimmer caps would then
end up in a favorable mechanical position.

Replaced a tubular 4.7 pf cap with a ceramic NPO disk part after the tubular
4.7pf broke. I was unsure whether
this was a suitable replacement, but in terms of stability and freq response
the disc looks good. Not sure
what  fabrication the tubular cap was.

Crunched the tabs on the Jackson drive.

Replaced both type #44 lamps with #47 lamps (vice versa?).

Cleaned the cheapie rear rotor(?) clamp on the air variable  with contact
cleaner and tried to lightly compress it with a Channellocks.

Carefully rebuilt the mechanicals.

Good news: The warble appears to be significantly lessened., although it's not
perfect.

Bad news: I can't realign the darn thing.  I tried to use the adjustment tools
that Radio Shack sells--little
plastic wands of little substance--and I cannot budge the VFO coil. One tool
actually twisted apart in the process.

How much force can I use on the VFO coil? Any reasonable way to loosen it? Is
there a better tool to use?
Should I just get  a CB license for all out of band operation? ;-)

If I can budge it, I believe the recommendation was to adjust the coil at the
low freq end and the trimmers
at the high end?

The though of disassembling that thing one more time is--discouraging!

Thanks,

Jeffrey N0IRR

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