Topband: Rotator creating spur on 1820- results

[k8gg at voyager.net]

Hi Jerry & Topbanders,

Doing the math from the info below:

AM 890 x 2 = 1780 KHz + 1730 KHz = 3510 <- - your 80 meter birdie.

I hope this makes sense and helps solve the puzzle.

As I noted before, it is probably generated off site by some rusty
connection in a radio tower that is a nasty diode as well.

73,  George,  K8GG...



> *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
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>