Hi Jim and Nate,

even if this might seem like nitpicking, I would like to add a tidbit
that is definitely intermodulation.
A manufacturer of N series RF connectors with gold metallization for the
inner contact areas (... a better quality grade...!!) they had to test
for incredible -160 dBc !!!! of intermodulation. As it seems, the gold
layer created something a bit similar to a schottky diode on the metal
surface.
So as improbable as it might seem, it is not only rusty TX towers, but
also cabling and connectors can add to your difficulties in a dense RF
populated environment.....

Greetings
Jochen Feldhaar DH6FAZ


Jim schrieb:
>
> ----- Original Message -----
>
> *NOW* we seem to be using the term "intermod" to descibe those
> former situations where disimilar metal contact (rusted bolts
> or tower sections) resulted in "the rectification of RF" and
> there result is "mixing" (the so-called "detection" process
> results in both a DC term plus a *rich* RF spectrum!!!!) and
> noise generation ... but I would not be prone to term this a
> case of 'passive intermod'.
>
> We used to call that a case of "poor bonding", allowing poorly
> connected tower sections to creak and create noise!
>
> More on this later, time permitting ...
>
> RF Jim
>
> >
> > He describes it better than I do... *and* he's another "RF Jim"!  (GRIN)
> >
> > [I got the joy of hunting for four hours on a hot airport ramp for a
> > squawking Aircraft ELT (Emergency Locator Transmitter, for those reading
> > along, I'm sure Jim's up-to-speed on that TLA...)... Hangars make for
> > lovely "RF chambers" for the RF to bounce around in and off of... we had
> > the Airport folks open one hangar and nope... it was the hangar right

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