Operating a VHF or UHF stationary repeater in a potentially
high RF environment ( i.e. other repeaters nearby) with a mobile
style receiver ( maxtrac ) and no filtering of any kind ( Like a
bandpass/reject duplexer) is not a suggested configuration in my world..
In many sites this will yield interference from other nearby
repeaters due to RF overload...
Unshielded cables for mic wires and rx vol hi wires in a
high RF environment is also not suggested.
Mobile duplexers ( not suggested in this case) are designed
to protect you from yourself and pretty much that is all they do...
but in a station duplexer with pass/reject filtering .. it is
designed to protect your receiver from overload from just about all
sources besides a mobile or portable within a couple hundred
kiloherts.. and any of that off freq is supposed to be filtered by
your I.F. filters..
They are suggested for many other reasons besides a single antenna
solution....if the interference is overload.. it would probably help...
Alternately try a bandpass filter on your rx, if that does not help,
then the source of the interference is probably another
transmitter... and without friendly support from the owner may be
difficult to resolve...
Doug
KD8B
At 11:10 AM 6/23/2009, you wrote:
>The receive radio has a 20 ft piece of RG-58 Belden and the TX radio
>has 40 ft of LMR 400. After I had already purchased and installed
>the LMR braid cable I then learned to my knowledge this was not
>recomended for duplex use and it could cause noise and other
>problems but there is no LMR on the receive end of the radio and it
>still does it when the TX radio is turned off.
>
>--- In
><mailto:Repeater-Builder%40yahoogroups.com>Repeater-Builder@yahoogroups.com,
>"Chuck Kelsey" <wb2...@...> wrote:
> >
> > Like Nate said, sounds like an intermod product with your
> transmitter being
> > part of the mix.
> >
> > My standard question has become -- are you using any LMR400, 9913
> or similar
> > foil/braid coax anywhere in your system?
> >
> > Chuck
> > WB2EDV
> >
> >
> >
> > ----- Original Message -----
> > From: "agrimm0034" <agrimm0...@...>
> > To:
> <<mailto:Repeater-Builder%40yahoogroups.com>Repeater-Builder@yahoogroups.com>
> > Sent: Monday, June 22, 2009 11:24 PM
> > Subject: [Repeater-Builder] Completly Stumped on Noise (UHF Repeater)
> >
> >
> > > This noise in my repeater has me completly stumped. I've tried
> everything
> > > I know possible to make it stop but nothing has helped. Here are some
> > > quick specs on what my repeater is...
> > > GMRS repeater RX 467.600 TX 462.600 DPL 054 TX 30 watts.
> > >
> > > My local repeater when I key opens up to a scratchy noise with the local
> > > police department in the background. It ONLY opens up when they
> key up the
> > > same time my repeater is being keyed. It is not perfectly clear it is
> > > scratchy but I have no idea how they are squeezing in on myn. I did find
> > > there frequency's and location of there repeater so mabye
> someone can help
> > > tell me what is wrong. Here is the Police Dept Repeater Details...
> > > PD Repeater - RX 460.4500 TX 465.4500 PL 6A 75 watt. (There
> tower is also
> > > located directly across from mine roughly 1/2 mile horizontally
> > > separated.)
> > >
> > > I've also tried changing my frequency and PL tones and it still has not
> > > made one bit of difference. I'f someone could help me out I'd gladly
> > > appreciate it. Thanks
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> >
>
>
