Chris.. I have done what you are talking about several times. And what they are talking about with the cavity is that u tune the notch side the the can to notch out the repeaters TX freq and tune the pass for what the link radio will be operating at to the middle of the frew that are used for tx and rx on the link radio if different if the same simplex operations is used tune the pas for that freq so the tx and rx will pass thru. and the reject is knocking the repeaters tx freq out and you can do the same for the repeater on the rx side with one more can also... tuned to pass the repeaters rx side and reject the links tx side... but if you have no problems with the link causing harm to the repeaters rx'er than dont worry about it but i would check it out anyways with a week single present and the links tx ON and while still listening to the local rx turn the link TX of ans listen for a difference...listen for desense... Good Luck Brent KF4TNP ----- Original Message ----- From: "Chris Peterson" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, January 08, 2005 8:15 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 > > > > > > > > --- > [This E-mail scanned for viruses at TNWEB LLC] > > --- [This E-mail scanned for viruses at TNWEB LLC] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
