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 <*> 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/
