*I put the strap around the rotator today. I no longer have a birdie on
1820. Not a trace of it on any antenna. Based on symptons, I can only
conclude it was caused by intermittent contact at the rotator bearings
or by intermittent contact at the bearing on top of the tower. Diodes
inside the rotator do not seem to be a problem.**
**
**The strap had no effect on my 3510 spur, which means the mixer for
that one is somewhere else. That one is not a big problem because it
goes away at nighttime due to one of the stations being daytime only.**
**
**The strap is 1/4 inch diameter twisted (not braided) stranded tin
plated wire, very flexible. Length is about 16 inches.**
**
**Special thanks to Lloyd N9LB and Hank K7HP who had the correct answer.**
**
**Jerry, K4SAV - happy camper*
On 11/2/2017 5:27 PM, K4SAV wrote:
Likely all the spurs you see on 160 that are caused by AM stations
will land on 10 kHz increments because the stations are spaced on 10
kHz increments. I identified one of the stations that was a big
contributor to my problem and that was on 1730. I haven't found the
other station yet. I expected the station on 890 to be a contributor
since it is only 1700 ft from my antenna but I don't think it is the
one. (It is a contributor to the spur that happens on 3510).
Regardless of which stations are involved, the main problem is that
the mixing is being created near my rotator, and probably inside it
somewhere. I have to kill the mixer somehow. More than likely the
stations are clean. It will be interesting to see if the same mixer
is causing both spurs, 1820 and 3510. Fortunately the 3510 spur goes
away at night because one of the contributor stations is daytime only.
Interesting video by N8PR, but he is fighting a different problem from
what I have,
I do not have a strap around the rotator. That's worth a try. Thanks
Lloyd and Hank.
Jerry, K4SAV
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