Hi Chris,
Ok, I was not understanding that you were only half duplex on the
remote, I would guess that you are linking to another repeater in this way?
This totally does work, the only drawback to running this way is the
courtesy tone and squelch tail for the other repeater are re-broadcasted
through your repeater. You probably already know this but a better solution
is to use a common link freq. for both TX and RX for the link. This of
coarse would require the other repeater to have a remote radio on the same
freq.
Maybe you do not have that option available but if you could swing it,
this makes a very seamless link because no tones or squelch tails are
rebroadcasted. Also this allows a nice pass cavity to be attatched in
between the link radio and its antenna. This filters both TX and RX since
they would be the same freq. eliminating the need for a notch filter. It
sort-of kills two birds with one stone because it provides isolation both
ways. I have a feeling that this might kill the squeel.
If that just isnt a viable solution, then one more thing, besides a
notch filter, to buy more isolation would be to provide plenty of vertical
seperation between the remote and repeater antennas.
Hope you get the RX working to your satisfaction, I use a Micor
receiver on my repeater system as well, they are good receivers when they
are tuned up. I also use a Pass/Reject duplexer and have a TE systems
preamp between the duplexer and the receiver. That is another advantage of
using pass cavities on RX (or in my case the Pass/Reject duplexer) You net
much more usable gain out of a preamp. This perked the RX on my machine
right up, The repeater can hear HT's a little better than they can hear it
back. Its nice to have a machine that isn't an "alligator", all mouth and
no ears ;-) ain't this repeater stuff fun? :o)
Wade - KR7K
----- Original Message -----
From: "Chris Peterson" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, January 08, 2005 7:15 PM
Subject: Re: [Repeater-Builder] in-band linking update
>
> Hi Wade,
>
> Thanks for the suggestions. I guess my gutt told me the proper tune-up
> procedure was the way to go. We just didn't have the time to do it at the
> time.
>
> I have one question about what you said. You say I should have
pass-reject
> duplexers on both systems. How can I put a pass-reject duplexer on a
radio
> that has only one antenna port? I can see why the filtering would be
> helpful, but the remote base is operating in half-duplex so it really
> doesn't seem necessary.
>
> There is a good duplexer on the repeater itself, and the link doesn't
appear
> to desense the repeater. Frankly, I don't care if the remote base is
> desensed a little, as long as I can receive the repeater at the other end,
> which I can. I do notice a quiet squeel in the background of the received
> signal on the remote, which I assume is the repeater's transmitter. I
think
> putting a notch can on the remote base, to notch out the repeater's
> transmitter, might do the trick.
>
> The squeel, while annoying, isn't a big deal right now. The repeater
itself
> id deaf as a post, and we know that is attributable to the Micor receiver
> itself.
>
> Thanks and 73,
> Chris, KG0BP
>
>
>
> ----- Original Message -----
> From: "Wade Lake" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Saturday, January 08, 2005 6:21 PM
> Subject: Re: [Repeater-Builder] in-band linking update
>
>
> >
> > The UHF Micor Mobile was a little tricky to tune, especially the
AFC
> > type. I would take care to follow the tuning procedure as outlined in
the
> > manual to the letter.
> >
> > Also, I am not sure what isolation measures you have already taken
> but
> > they would have to be fairly extensive for pairs that close in frequency
> to
> > coexist happily at the same site, in order to work properly. I would
> > suggest all 100% sheided cables - preferably Heliax, Pass/reject type
> > duplexers on both systems, and at least 1 extra high quality pass cavity
> on
> > both transmitters. This is just for starters. Each site is configured
> > differently so there may be several other measures to take. Good earth
> > grounds to all components of the system and extra sheilding for mobile
> > radios used in a full duplex environment are 2 other necessary things to
> do.
> >
> > It sounds like you have quite the system, and you are probably
aware
> of
> > the suggestions I am making here but sometimes the obvious things are
the
> > easiest to forget. Sounds like your getting there.
> >
> > Best of luck to you and 73,
> >
> > Wade - KR7K
> >
> >
> >
> > ----- Original Message -----
> > From: "Chris Peterson" <[EMAIL PROTECTED]>
> > To: <[email protected]>
> > Sent: Friday, January 07, 2005 4:35 PM
> > Subject: [Repeater-Builder] in-band linking update
> >
> >
> > >
> > > All,
> > >
> > > A couple months ago I posted a question about in-band linking. I
> thought
> > > I'd post an update on how it seems to be working.
> > >
> > > The repeater is on 442.750+ running about 25 watts. It's a converted
> > Micor
> > > mobile.
> > >
> > > The remote base listens on 443.025 and transmits about 25 watts on
> > 448.025.
> > > The repeater it's talking to is about 90 miles away over a very good
> path.
> > > The remote base is an Icom 900 module attached to an FC-900.
> > >
> > > The repeater shows no obvious desense, and the signal strength of the
> link
> > > is full-quieting. There is one odity, though. The link seems to have
> > some
> > > sort of high-pitched, low--amplitude, squeel on it. I assume this is
> some
> > > spur from the repeater's transmitter. We plan to try to notch that
out
> > when
> > > we get a chance.
> > >
> > > There is one odity, though. The Micor has been in service for about 2
> > years
> > > now. When we first set it up, the receiver sensativity was about .35
> UV.
> > > Now, we can't get it to come below about .7UV. I should point out
that
> we
> > > didn't do the full tuning procedure, we just tried to tweak things
back
> > into
> > > place. Also, the Micor has not been checked since it was put in
service
> 2
> > > years ago... That is, it hasn't been checked until it was moved
> > yesterday.
> > >
> > > My question is, is there anything that commonly goes bad in these
things
> > > that might cause this? We have plenty of spare receivers around, so
> > that's
> > > not an issue, I was just curious if anyone had any ideas of things to
> > check.
> > >
> > > Also, does anyone have any simplified tuning instructions for the UHF
> > Micor
> > > mobile or any tips that might make the procedure go more smoothly?
> > >
> > > Thanks,
> > > Chris, KG0BP
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
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