Sounds like a similar problem here in Portland, Oregon. We have a guy running an IRLP node here on what is commonly thought of as 2 meter simplex frequencies. The station is on a broadcast tower with high elevation running about 375 watts ERP!!! Mobiles 100 miles away can clearly hear the IRLP node!! The IRLP node is made from amateur grade RF equipement & has had SEVERAL problems with causing interference with the inputs of other repeaters in the area. Attempting to talk to the owner & suggesting he put sharp cavity filters on the transmitter resulted in his reply of "then I wouldn't be able to be frequency agile".
Meanwhile, his deviation has been measured at +/- 9 KHz, and he argues that there is nothing wrong because a telecom service agency measured & set his deviation. ------ Original Message ------ Received: Tue, 21 Dec 2004 09:23:57 AM CST From: "Jim B." <[EMAIL PROTECTED]> To: [email protected] Subject: Re: [Repeater-Builder] HELP: 2 meter repeater intermod problem from pager transmitters > > Except that the vast majority of VHF transmitters/networks weren't > really capable of multi-freq on the fly as you describe. At least around > here, anyway, they were virtually all Micor PURC stations. > And most sites would not have allowed the transmitters to remain without > cavites anyway. > -- > Jim Barbour > WD8CHL > > > Joe wrote: > > > You will find less and less narrow band cavities on paging transmitters > > lately. As the paging industry slowly goes into their death spiral of > > loosing customers, they no longer need 2, 4 or more transmitters at each > > site to deal with the capacity of pagers out there. What some companies > > are doing is leaving one transmitter at the site and doing > > multi-frequencies out of a single transmitter (This is assuming they were > > all on the same band, 900Mhz for example.) When they multi-frequency a > > transmitter they need to remove any narrow band filters off the transmitter > > output. This may explain why some ham repeater sites that were quiet now > > have noise problems. The irony of it is that you see paging transmitters > > leaving a site and think that the noise floor is going to go down, only to > > find that the nose increases tenfold. > > > > 73, Joe, K1ike > > > > At 09:53 AM 12/21/2004, you wrote: > > > >>All paging transmitters involved should have narrow bandpass cavities > >>and circulators on their outputs. That's usually considered a must at > >>any site. If the paging company isn't willing to spend the money for > >>that, then they aren't to serious about staying in business. > >>The good news is that VHF common carrier paging is slowly going away, > >>and the remaining frequencies will likely be dropped and released back > >>into the general pool in a few years, or less. > >>There is virtually no VHF paging here in NE Ohio anymore. > >>-- > >>Jim Barbour > >>WD8CHL > > > > > > > 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/
