Thanks for the input from all of you. I went to the tower site this afternoon to give another look at the problem. The noise has gotten worst. Our receiver is greatly desensed. The only equipment on site is the site owner's UHF repeater, our two meter repeater and the Internet equipment. The site owners equipment doesn't seem to be affected. The strobe lamp puts a buzz in our receiver each time it fires. I noticed one of the green lamps on the Netgear switch get brighter when the strobe fires. I'm sure the Internet equipment is affected by that. The two meter is our primary machine used in our storm watch activities. I tried to contact the Internet company today with no answer. Will try again Monday. Again thanks for the information.
Jim WK5Y ----- Original Message ----- From: Eric Lemmon To: Repeater-Builder@yahoogroups.com Sent: Saturday, April 25, 2009 9:15 AM Subject: RE: [Repeater-Builder] Computer noise in 2M Repeater Jim, This situation happens all too often, and it usually occurs because cheap equipment is used (plastic boxes to contain the amplifier, unshielded cable, no ferrites, ineffective grounding. etc.) to keep the installation costs down. This is a misguided approach, because repeated visits to fix a leakage problem will always cost a lot more than a first-class system would have cost. Sound familiar? Another possible factor is that *some* wireless installers are primarily IT (Information Technology) folks who have relatively little experience with the RF environment at a repeater site. I have met a few of these clueless guys, whose eye glaze over when I talk about an interfering carrier from a CPU crystal or intermodulation. They're used to installing APs and bridges in office buildings, and don't see anything different about tie-wrapping a more powerful box to a tower that supports many other services, except perhaps using some electrical tape and silicone goop to waterproof the connectors. Don't laugh- it happens! So, to answer your question, immediately contact the wireless system owner and advise him that his system is interfering with yours, and it must be fixed promptly. Don't quote the FCC rules quite yet. If the polite approach does not get results, contact the site owner. Above all, do not just sit and wring your hands. The wireless owner must comply with Part 15 rules, but he must be told if there is a problem. 73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Jim Russell Sent: Friday, April 24, 2009 7:20 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Computer noise in 2M Repeater Does anyone have any suggestions on how to eliminate noise generated by a Wireless Internet System. The owner of the tower where our club has our 145.370 MHz repeater has rented space to a group who have mounted a wireless Internet "relay" on the tower. The system is simple, it consist of a Netgear switch, a Microwave dish and a smallYagi. There is approx. 300 feet of Cat 5 wire going up and 300 feet coming down the tower. Their antennas are mounted within a few feet of ours on the top of the 260 ft. tower. We unplugged the netgear switch and the noise cleared, we disconnected our antenna and the noise goes away. The noise rides on the repeater receiver squelch tail. We do use a PL tone or we wouldn't be able to use our repeater at all Jim WK5Y
