I looked at the duplexer with a spectrum analyzer and
a return loss bridge. It's making spec (100dB
rejection) on each side. PB loss is 1.1dB. I did
notice that the return loss indication on the SA
showed a very nice sharp deep null (over 60dB) when
looking into one port, while the other port was quite
rounded at the bottom and a lot wider, maybe only
going down to -45dB. As the duplexer was not mine and
is still under warranty and had just come back from
being checked out by TxRx, I did not play with any of
the tuning.
We also tried the repeater running on my spare Celwave
6-cavity pass/reject duplexer which has worked fine
before. This didn't help the situation at all.
If the PA and duplexer weren't happy together,
wouldn't I also get desense when running on the dummy
load also? Remember it's perfectly happy on a 500w
Bird load. We see no rise in signal level (down at
-130dBm) on the receive port of the duplexer.
Bob M.
=======
--- [EMAIL PROTECTED] wrote:
> At 08:09 11/22/2005, you wrote:
> >At 06:00 AM 11/22/2005 -0800, you wrote:
> >
> > >I'd like to try a circulator before buying one,
> since
> > >if it doesn't help the situation, it's a waste of
> > >money to have it there.
> >
> ><---Aside from presenting a pretty much constant 50
> ohm load to your xmtr,
> >why do you think a circulator will make a
> difference as far as desense is
> >concerned?
> >
> >Ken
>
> I once had an Exec II RFPA that didn't "like" the
> duplexer load it was
> TXing into. Had massive desense unless there was a
> circulator between the
> TX & duplexer.
>
> Bob NO6B
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
> [EMAIL PROTECTED]
>
>
>
>
>
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