[Heathkit] HW-16 Warble

[Ian Wilson]

Could be due to noisy grounding of the CFO variable cap. Try DeOxit on any
wipers that are in the ground path from the rotors. Also tighten grounding
screws in general

73, ian K3IMW

On Aug 19, 2016 4:37 PM, "Mark K3MSB" <mark.k3msb at gmail.com> wrote:

> Removed the 3 tubes in the TX chain, no effect.
>
> Once again, removed the VFO; no effect.
>
> Using a big eraser on a pencil,  I (again) proceeded to tap the snot out of
> everything I could find.   The only thing that made a difference was when I
> knocked around the VFO tuning capacitor.    Prior,  I had cleaned and
> reassembled the trimmer, so banging around the trimmer isn't a good test.
> But, with the plates half meshed, beating on the top of them will care a
> warble, but that may be due to proximity to the trimmer.
>
> Mark K3MSB
>
>
>
>
> On Fri, Aug 19, 2016 at 6:25 PM, Mark K3MSB <mark.k3msb at gmail.com> wrote:
>
> > Hi All
> >
> > Well, I saw no changes in the heater when the problem was occurring.
> >
> > I did notice a small flat topping of the positive side of the heater
> > waveform.  I'm not sure that is significant.   Here's a photo:
> >
> > http://www.k3msb.com/temp/Heater.jpg
> >
> > Part of the problem is that I may not have the correct equipment here to
> > see a very subtle change in a waveform on the scope.
> >
> > As mentioned in my first post,  I've replaced the tubes for which I have
> > spares.    The next plan (and I'm running out of plans.....) is to start
> > removing tubes in the transmit chain when the issue occurs.
> >
> > 73 Mark K3MSB
> >
> >
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