[Antennas] dipole

Sun Jun 11 15:30:44 EDT 2006

Ken Snipes wrote:
> Got my dipole up, but now im coming thru the wife's TV, doesn't do it 
> on the vertical, and the other neighbors dont see anything , at least 
> the ones i have checked.....any suggestion? I'm going to replace the 
> coax i used, it was a bit old... but i got 1.2 swr, and so i put the 
> dipole about 20 ft up . with it any suggestions about the TVI let me 
> know, thanks
>> ______________________________________________________________
> Antennas mailing list
> Home: http://mailman.qth.net/mailman/listinfo/antennas
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:Antennas at mailman.qth.net
>>We need to know if it is harmonic interference or front-end overload. 
I.e.: does the interference affect all channels or only certain 
channels? If all (or most) channels it is probably front-end overload, 
which would indicate that the TV antenna is getting much more RF from 
the dipole than from the vertical. This could be a problem of location 
(proximity of the dipole to the TV antenna). If harmonic interference, 
on the other hand, (where only a certain number of channels are 
affected) it could be due to bad connections somewhere in the antenna or 
feed line, causing non-linear conduction (rectification) and generation 
of harmonics in the antenna itself. Or in an extreme case, often not 
recognized, rectification in a nearby corroded or rusty metal object. I 
had this trouble in an apartment in which I lived at one time where my 
dipole ran too close to an old (rusty) fire escape. The TVI only 
happened when I operated on 40 meters. The apartment building had a 
built-in antenna system for all the apartments in the building so I 
caused TVI to all the tenants!
Hope this is helpful.
73,
Harvey/W4TG