[RFI] DFing intermittent connection

[Steve London]

This is a little off topic from the usual, but the expertise in DFing on
this forum is outstanding.

I am a serious contester, and do lots of SO2R. That means I need to be able
to listen on one band while transmitting on another band. With filters and
stubs I have brought the harmonic and overload energy down to acceptable
levels. However, I have recently developed a new problem. Something on the
tower is intermittent and causing the level of the 2nd harmonic to vary
many S-units as the wind blows or I turn the rotator on the 40 meter beam.
When this happens it creates hash across the band. I have looked for the
obvious, but no luck yet. Yes, it could be something loose on the 40 meter
beam hardware, but before I take on the project of taking it down, I would
like to pinpoint the source. I am a tower climber, so I can get close to
everything on the tower. What are the options for something handheld, very
directional, and not overloaded by the fundamental ?

73,
Steve, N2IC