Johnson Ranger VFO advice please
rsahlen at VOICENET.COM
Sun Sep 17 21:18:20 EDT 2000
If you have the optional ptt installed, there is a pair of
15mf electrolytics which are part of the 6al5 bias circuit
and they wreak havok with the vfo when they start to go. You
can't see them without removing the top of the compartment.
As I recall, the original I pulled from mine was a single
cardboard tube with the pair inside. They were going dry and
in my case caused a nasty hum/buzz in the vfo until replaced.
On Sun, Sep 17, 2000 at 02:17:15PM -0700, Leslie Zwiebel wrote:
> I'd appreciate hints re a problem w/ my Ranger on AM:
> QSO reports on 3.870 are that FSK-like activity is heard behind my
> decent power/decent audio signal, as if I am also sending a RTTY signal
> I can hear it myself when I "Zero" in the shack using the Ranger in
> order to spot the net frequency I am hearing on my receiver.
> On-air front panel metering shows no probs.
> Helpful local AM'ers have suggested, and we have tried the
> following: inserting a crystal and running rock-bound, which eliminates
> the problem, pointing to the VFO as culprit.
> It does not occur (signal is clean) on 40M(!), so we are thinking
> about components in the 160M/80M/ loop.
> Two or three substitutes for the 6AU6 in the VFO are no help. Will
> also try a sub for the OA2 VR tube. Poking around at solder joints and
> grounds, at least the visible ones with the VFO cover off has not
> yielded any change.
> Will probably next start VOM measurements on top layer of the VFO
> Before we start taking off the panel to access further layers of the
> VFO (alot of work), I'd appreciate any ideas.
> Menlo Park, CA
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