At 22:07 11/23/2005, you wrote:
>--- In [email protected], "Bob M." <[EMAIL PROTECTED]> wrote:
> >
>
> > There's an unused 800 MHz vertical antenna mounted
> > near the UHF antenna, on the platform, with coax
> > attached. Apparently the dummy load at the bottom of
> > the coax for that antenna was either missing or
> > defective, so another one was put on. The repeater's
> > desense problem is completely gone now, even with the
> > 200w PA and the 17dB gain preamp.
>
>
>Maybe it's because it is late, but why would an unused, unterminated
>antenna be the cause of this desense??
Good question. Only good answer I can think of is that the reflection off
the open connector resulted in a voltage or current maximum at a "weak
spot" in the line such as a corroded connector or previously arced spot
(due to previous lightning strike - we have a couple of those in our systems).
An open N or BNC connector will NOT significantly radiate at or below 500 MHz.
Bob NO6B
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