>> //Seems obvious this is NOT a parasitic, it's a product created
>> elsewhere. I've seen this kind of thing many times in densely populated
>> contest stations, and it's often quite surprising what's caused it...things
>> like oxidized guy cabling, all sorts of stuff.
>
>Amen, Steve.
>
>If he tried a dummy load on the amp, and there was no birdie
>then, it seems to me, it is narrowed down to the antenna system
>or the ground system. Like you, I have seen many weird things
>happen at contest stations and repeater sites. Mother Nature is
>very adept at making diodes at almost any kind of metal joint.
>It is easier on vhf and uhf situations, as one can usually run down
>the source with a portable directional antenna.
In my experiences, loose joints make a plethora of HF harmonics well up
into the VHF region. Thus, finding loose joints can be done with a
portable FM receiver. Suitable modulation can be 60wpm dits.
>
>I would check all the connections on the antenna system and the
>grounding system. Have someone go out and shake the guy wires
>and tap things with a hammer while you listen in the shack.
>
I've seen a guy-wire radiate ch 2 TVI for a quarter mile. (the 4th
harmonic of 14MHz)
>...
good advice, Phil
>
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>
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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