Our 6-meter machine in Springfield, MO had an issue with a "noise" on the RX side. RX on 51.570 with TX RX duplexers and a dual cavity TX RX 11-18-06 bandpass filter on the front end, and we were getting a "gurgling" type noise. If we didn't run a PL, the squelch would hang open until the repeater shut down. The problem only seemed to occur after about 4 p.m. and usually went away around 9 or 10 at night.
We were determined not to install the repeater at the final site until we could make sure that there was not a problem with the repeater. After a couple weeks of checking and double checking and and looking for interference, we finally found it . . . . It was an Apex 24" TV! Shutting it off resovled the problem. You just never know when it's 6-meters! Lots of noise out there, but, that's part of the fun, too, is the extra challenges of putting up a 6-meter machine. On Fri, Dec 26, 2008 at 9:14 AM, Milt <men...@pa.net> wrote: > A similar war story from back in the early 90's...Commercial customer > with a 35MHz base complaining of dramatically reduced range. Base and > mobiles checked out fine, antenna system fine, just trouble receiving the > mobiles. Dropping the PL with the antenna connected I noticed what seemed > to be a constant carrier. A bit of wandering about with a scanner using > increasingly short lengths of wire for antennas brought me to a nearby > house. The noise seemed to be radiating on the telephone line and the power > line. The house was a rental owned by the company with the radio so after > proper contact was made an inside sweep found the ... telephone answering > machine!?!?!?! > > The device was powered by a wall wart supply with an very long cord > (getting any clues yet?); which had recently come back from a repair > center. The wall wart had a slightly audible hum. A snap together > ferrite with as much of the excess power wiring wound onto the ferrite as > possible, and another ferrite on the telco line brought the noise to a level > that was not detectable at the base station. > > Milt > N3LTQ > > > ----- Original Message ----- > *From:* neal Newman <cozy...@yahoo.com> > *To:* Repeater-Builder@yahoogroups.com > *Sent:* Friday, December 26, 2008 9:39 AM > *Subject:* Re: [Repeater-Builder] Six Meter Repeater Noise Issues > > Noise on the six meter repeater. > On my machine 53.67 in New jersey I was getting noise that was holding > the machine Keyed up. then drop. and key up again. I thought it was desense > Even with a big expensive > Commercial Duplexer. with the transmitter off, the normal unsquelched Hiss > sounded Fine No noise that we could detect. after weeks of this. We finally > found out what the Problem was. the 2 meter,and 440 machines next to it ran > just fine.however They both had an IRLP link on them. The Noise problem > turned out to be the Router/switch. > The Noise it was creating was just at the threshold level to Key and hold > open the repeater. > BTW. The 6 meter machine was in PL with a Tone of 67hz...... Not a good > choice. > between the60 cycle noise of a bad wall wart for the router switch and the > noise it created. > might as well put a flea power transimitter with PL sitting on the > repeaters input. > changed the router swich and PL tome. and Problem wentt away. > Verizon uses cheapo routers. we placed the new one in a shielded box > > Neal-KA2CAF > > --- On *Thu, 12/25/08, Mike Morris WA6ILQ <wa6...@gmail.com>* wrote: > > From: Mike Morris WA6ILQ <wa6...@gmail.com> > Subject: Re: [Repeater-Builder] Six Meter Repeater Noise Issues > To: Repeater-Builder@yahoogroups.com > Date: Thursday, December 25, 2008, 10:12 PM > > At 11:06 AM 12/25/08, you wrote: > > Hi To All & Hope everybody had a good Christmas, > > While the subject was brought up, I have been having a similar experience > here at my location. > It is not on a repeater, but a simplex radio (vertex VX3000l mobile) for a > base on the natl Red Cross freq of 47 mhz. > In the daytime the receiver is quiet and hears fine. > It seems as about the time the sun starts going down, the receiver's > squelch opens and has a constant static noise for many hours but still > receives fine. > It may do it all night, I don't know, I haven't stayed up to see, just > leave the radio on and go to bed. > Was wondering if could be power line noise (but why wouldn't do in daytime > also)? > Is there any interference to the HF bands like this at night? > > Thanks, > Mike KB5FLX > > > An old trick - if the on-time changes about 6 minutes a day then it's > light-dependent (i..e a photo-electric triggered yard light). > > In your shoes I'd power the radio from a gell-cell, > and then go flip breakers off one at a time. > That will tell you if the noise source is inside > the house, and if so, on which breaker. > > Mike WA6ILQ > > > > -- James Adkins, KB0NHX District 1 Technical Field Engineer Troop A--Lee's Summit; Troop H--St. Joseph Missouri State Highway Patrol 504 SE Blue Parkway Lee's Summit, MO 64063 816-622-0707 ext. 235 417-840-5261 (Cell) "I'm James Adkins and I approve this message"
