Topband: Rotator creating spur on 1820- results

K4SAV RadioXX at
Sat Nov 4 19:40:23 EDT 2017

*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 -

More information about the Topband mailing list