The fix was repeater A to replace a notch filter they had on the repeater to notch out repeater B.
David ----- Original Message ----- From: Nate Duehr To: Repeater-Builder@yahoogroups.com Sent: Sunday, November 11, 2007 3:40 PM Subject: Re: [Repeater-Builder] Possible interference on 146.160 On Nov 11, 2007, at 8:34 AM, David Murman wrote: > I also had intermittent interference coming from two amateur > repeaters. I maintain an ARMY MARS repeater and when repeater a and > repeater B were on it produced a signal within 5 khz of the input to > the ARMY MARS repeater. Both amateur repeaters were located on top > of the same building. The MARS repeater was located some miles away. > > It took a little looking at a spectrum analyzer to find the two. > Repeater A minus repeater B plus repeater A = interference to MARS > repeater. > That math works out on any three repeaters with the same offset. Doesn't matter if they're Amateur, MARS, commercial... 5 MHz split on all three, means there's an opportunity to mix from two transmitters plus one input, to another input. What would be more interesting is what you did to mitigate it. Was the mix happening externally or in one of the systems? Someone forget to install an isolator? Little to no filtering on a high-level pre-amp on the MARS repeater? What was it? -- Nate Duehr, WY0X [EMAIL PROTECTED]
