Re: [Repeater-Builder] a strange unexplainable desense issue
Hey Jed, You are leaving out a key piece of information. Your antennas are at the same height and almost next to each other causing a mixing problem that I explained to you. The problem will not go away until the antennas are separated. You proved this by killing each transmitter separately and the problem goes away. If you look on a spectrum analyzer when both machines are keyed you will see the mix. When I talked to you on the phone about this problem I gave you the mixed frequency to look for on 220. When the machines left the factory they were both on frequency and checked with 2 different IFR's that were recently calibrated. Even if the machines were off by not even 1kc it would not cause this problem. I think since you said both are off by about the same amount you might want to look at what ever your using to measure them. Paul Maggiore V.P. AA3VI Maggiore Electronic Lab (HiPro) Best Weight Loss Program - Click Here! http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTFoYdQPLtnbksoClURHCwdUYQowpN4jCEaG6izKUkjb0Vua2cjHva/
RE: [Repeater-Builder] a strange unexplainable desense issue
actually the problem did not go away. We tested it yesterday with UHF completely off, and 220 just kep making tons of noise. In fact, UHF plays fine stand alone, i had to turn 220 off when we left the sight. Any ideas? I think this is more of an issue of something getting in to the input of 220. Even stand alone without UHF even turned on, it's an issue. Thoughts? -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of repeat...@juno.com Sent: Sunday, September 20, 2009 10:19 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] a strange unexplainable desense issue Hey Jed, You are leaving out a key piece of information. Your antennas are at the same height and almost next to each other causing a mixing problem that I explained to you. The problem will not go away until the antennas are separated. You proved this by killing each transmitter separately and the problem goes away. If you look on a spectrum analyzer when both machines are keyed you will see the mix. When I talked to you on the phone about this problem I gave you the mixed frequency to look for on 220. When the machines left the factory they were both on frequency and checked with 2 different IFR's that were recently calibrated. Even if the machines were off by not even 1kc it would not cause this problem. I think since you said both are off by about the same amount you might want to look at what ever your using to measure them. Paul Maggiore V.P. AA3VI Maggiore Electronic Lab (HiPro) Best Weight Loss Program - Click Here! http://thirdpartyoffers.juno.com/TGL2142/fc/BLSrjpTFoYdQPLtnbksoClURHCwdUYQ owpN4jCEaG6izKUkjb0Vua2cjHva/
RE: [Repeater-Builder] a strange unexplainable desense issue
Beyond just turning off the other repeaters, try terminating their antenna feedlines with a dummy load instead of leaving them connected to the equipment. See if that makes any difference. -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Jed Barton Sent: Sunday, September 20, 2009 10:59 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] a strange unexplainable desense issue actually the problem did not go away. We tested it yesterday with UHF completely off, and 220 just kep making tons of noise. In fact, UHF plays fine stand alone, i had to turn 220 off when we left the sight. Any ideas? I think this is more of an issue of something getting in to the input of 220. Even stand alone without UHF even turned on, it's an issue. Thoughts? -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com ] On Behalf Of repeat...@juno.com mailto:repeaters%40juno.com Sent: Sunday, September 20, 2009 10:19 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: Re: [Repeater-Builder] a strange unexplainable desense issue Hey Jed, You are leaving out a key piece of information. Your antennas are at the same height and almost next to each other causing a mixing problem that I explained to you. The problem will not go away until the antennas are separated. You proved this by killing each transmitter separately and the problem goes away. If you look on a spectrum analyzer when both machines are keyed you will see the mix. When I talked to you on the phone about this problem I gave you the mixed frequency to look for on 220. When the machines left the factory they were both on frequency and checked with 2 different IFR's that were recently calibrated. Even if the machines were off by not even 1kc it would not cause this problem. I think since you said both are off by about the same amount you might want to look at what ever your using to measure them. Paul Maggiore V.P. AA3VI Maggiore Electronic Lab (HiPro) __ Best Weight Loss Program - Click Here! http://thirdpartyoffers.juno.com/TGL2142/fc/BLSrjpTFoYdQPLtnb ksoClURHCwdUYQ http://thirdpartyoffers.juno.com/TGL2142/fc/BLSrjpTFoYdQPLtnb ksoClURHCwdUYQ owpN4jCEaG6izKUkjb0Vua2cjHva/ No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.78/2347 - Release Date: 09/20/09 06:22:00
RE: [Repeater-Builder] a strange unexplainable desense issue
At 07:58 AM 9/20/2009, Jed Barton wrote: actually the problem did not go away. We tested it yesterday with UHF completely off, and 220 just kep making tons of noise. In fact, UHF plays fine stand alone, i had to turn 220 off when we left the sight. Any ideas? I think this is more of an issue of something getting in to the input of 220. Even stand alone without UHF even turned on, it's an issue. Jed, you REALLY need to run an intermod program to have a look at the possible products created. In addition, it is not necessary for a transmitter to actually be active in order to create intermodulation products. Hell, it doesn't even need to be powered! Find out if the other transmitters at your site use isolators. And you might want to consider adding some to YOUR equipment as well. That will, at least, eliminate non-linear generation (intermod) of products in YOUR equipment Ken -- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net We don't just make 'em. We use 'em!
RE: [Repeater-Builder] a strange unexplainable desense issue
we have not tested that yet, that is our next test. -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Phil Hebert Sent: Saturday, September 19, 2009 8:39 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] a strange unexplainable desense issue Disconnect the antenna at the duplexer and replace with a dummy load. Does the problem still exist ?
[Repeater-Builder] a strange unexplainable desense issue
Hey guys, Alright, i have a very strange problem on 220. Let me explain the equipment. The repeater is a hipro r1, with an arcom rc210 controller, hustler 220 antenna, and wacom duplexer. I'm getting this very strange feedback in to the 220 receiver. The problem only occurs when the 220 transmitter is keyed. We checked the duplexer and it appears perfect on a service monitor. After having gotten the repeater back from hipro, we measured it, and it shows up -.71 KHZ off frequencyy, in terms of the transmitted signal. To me this seems way off, but according to hipro it's within spec. I let the crystals warm up for a good 10 minutes before doing this test. For cable between the receiver and the duplexer, and the transmitter and the duplexer, it's rg142. Any ideas guys? I've been given a theory that it may be the antenna, since they are not that good at repeater service. The antenna is mounted on the roof of a hospital. Now, let me explain another problem. I have a hipro r1 uhf machine, and it's showing up about the same amount off frequency. There are 2 things happening when that is keyed up, it's keying up our 900 repeater at the same sight, and also causing the squelch on the hospital's security repeater to chrchunk. Any ideas? I'm at a loss. Thanks, Jed
RE: [Repeater-Builder] a strange unexplainable desense issue
Disconnect the antenna at the duplexer and replace with a dummy load. Does the problem still exist ?
Re: [Repeater-Builder] a strange unexplainable desense issue
At 9/19/2009 17:25, you wrote: Hey guys, Alright, i have a very strange problem on 220. Let me explain the equipment. The repeater is a hipro r1, with an arcom rc210 controller, hustler 220 antenna, and wacom duplexer. I'm getting this very strange feedback in to the 220 receiver. The problem only occurs when the 220 transmitter is keyed. Got a 1600 AM radio station in the area? We checked the duplexer and it appears perfect on a service monitor. After having gotten the repeater back from hipro, we measured it, and it shows up -.71 KHZ off frequencyy, in terms of the transmitted signal. To me this seems way off, but according to hipro it's within spec. I let the crystals warm up for a good 10 minutes before doing this test. For cable between the receiver and the duplexer, and the transmitter and the duplexer, it's rg142. Any ideas guys? I've been given a theory that it may be the antenna, since they are not that good at repeater service. The Hustler G7-220 is a reasonably good antenna; doubt it's your problem unless there's a loose joint/corrosion problem. The antenna is mounted on the roof of a hospital. More likely that some other electronics on or just below the roof is causing a mix. Bob NO6B
