The reason that I know that there is a high power ( certainly illegal ) cb operator virtually right under my repeater's antenna, is that the owner of the tower told me when I was installing my system that the 'kid' next door was coming over the business telephone system in the building at times and hoped that I wouldn't. He said that he had gone over there to see if who was at the business end of the mobile fibgerglass antenna bolted to the side of the metal buidling next door. The guy was proud of his little station. If I find that he is getting into my repeater, the local FCC Field Office will get TWO letters. One from me on my repeater interference the other from the owner of the tower about the interference to his phone system. - Mike
From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of JOHN MACKEY Sent: Thursday, February 26, 2009 5:58 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Interference or Intermod ( ? ) Help....here goes Don't analog TV receivers us an IF of 45 MHz? About 15 years ago I lived in an apartment where I had a 29.6 Mhz Mocom 70 remote base and a LPB series 330watt Motrac base on 52.525 MHz operating from a Utility room about 200 feet away. Both were connected by DC remotes to myself and another ham in the same apartment complex. Suddenly, after about a year of my base stations working fine, I received complaints that my radios were interfering with clock radios, phone answering machines, stereos, etc. Several people in apartments around were pointing the finger at me, because everyone knew the antennas were mine. But both of us were not home when the interference occurred (myself and the ham in the other apartment who shared remote use of the base stations). The things people reported hearing sounded like CB. Taking a brief walk around the complex I found a semi-cleverly hidden "big stick" CB antenna, with white coax leading into an apartment of a new tenant. When he came home I spoke to him and he proudly showed me his system, a CB radio with a big amp hooked up running about 300 watts. Looking at it with my spectrum analyzer showed it raised the grass level 20 DB and very little power was on frequency. We switched the map to low and it was producing about 175 watts, all on frequency, and the grass on the analyzer was acceptable. I ask the guy to keep the amp on low power and showed him the analyzer running on both hi and low so he could see that in hi power he wasn't getting any power on channel. I always knew when he switched into hi power. ------ Original Message ------ Received: Thu, 26 Feb 2009 02:32:21 PM PST From: "Michael Ryan" <mryan...@tampabay.rr.com <mailto:mryan001%40tampabay.rr.com> > To: <Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> > Subject: RE: [Repeater-Builder] Re: Interference or Intermod ( ? ) Help....here goes > I am told that There IS IN FACT a high power cb operator working from a > building about 50ft from the tower where the repeater's antenna is mounting. > I never considered that an option.tell me you're kiddin'. - Mike > > > > From: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> > [mailto:Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of james f potter > Sent: Thursday, February 26, 2009 11:41 AM > To: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> > Subject: Re: [Repeater-Builder] Re: Interference or Intermod ( ? ) > Help....here goes > > > > Hi Possib. a high power C.B. operater. > > ----- Original Message ----- > > From: skipp025 <mailto:skipp...@yahoo.com <mailto:skipp025%40yahoo.com> > > > To: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> > > Sent: Thursday, February 26, 2009 9:51 AM > > Subject: [Repeater-Builder] Re: Interference or Intermod ( ? ) Help....here > goes > > > > I remember that Neutec Unit... saw it on Ebay. > > Mike > > Do you have any analog television stations on channel(s) 11 > through 14 in the area still on the air? > > If so, I might suspect an IF image might be possible. I had > the same type of problem here from channel 13 getting into a > number of Icom receivers. > > I had to notch the image frequency of my IF to get rid of > it. > > s. > > > "Michael Ryan" <mryan...@...> wrote: > > > > My recent efforts at putting a 220 repeater on the air here in western > > Florida have been mildly succesful. I am using a Neutec designed > repeater. > > ( I know there are some uhf and vhf models around, this one is on 220, a > > RANGER brand ). The repeater is open access. And runs quiet all day or > > night, nothing cracking the squelch at all. But during times when > there is > > a conversation going on after a few minutes a rather nasty signal > captures > > the repeater sometimes in short bursts, sometimes much longer. > "Sounds like > > someone talking into a reverb chamber.." I had been using a Mirage > brick > > amp in the rack, but suspected that this amp might be the problem, some > > oscillation or internal mixing of some sort. This turned out not to > be the > > case, the amp though still in the circuit is OFF but we still get the > > garbage. When the amp would be ON, and I would sometimes hear this > stuff > > start, and I could turn OFF the amp an it would stop. But shortly later > > even with the amp OFF, it is back.very odd that it would appear to me. > > > > Now, all cables in the rack are RG-400. Every one in the rack. Half > inch > > hardline runs to the antenna, though there is a splice with a double > male N > > connector as I recall. The Neutec unit does about 25 watts output > but I have > > it cut back to about 10 watts thinking it will run cooler. Thus > with the > > small brick amp it was doing about 65 watts output to the Telewave 4 > cavity > > duplexer. > > > > While at the site tonight, I could hear something getting into the > recvr. > > The repeater was UP, but no one talking at that moment. Again, > nothing on > > it's own ever appears to break the squelch. The noise was heard > through the > > repeater's on board speaker, meaning it was coming through the antenna / > > recvr and not something produced in the rack I would assume. > > > > There is a cel tower about 1,000ft away and another tower with ( who > knows ) > > how many other users, another 500ft further away. Based on this > little bit > > of info what would the masses suggest in first FINDING the offending > source > > if is indeed intermod? Then, is there much than can be done short of > > moving my machine? Any ideas or suggestions? > > > > n Mike > > > > _____ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.0.237 / Virus Database: 270.11.3/1973 - Release Date: 02/26/09 > 07:03:00 > > > > > > __________ NOD32 3893 (20090226) Information __________ > > This message was checked by NOD32 antivirus system. > http://www.eset.com > > __________ NOD32 3893 (20090226) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com
