I believe the inital posting stated no freq combination/mixing could be found. For the most part this would illimate an intermod problem. However, since there are so many txs in a typical city part of the problem could be from a distant unknown tx.
73, ron, n9ee/r >From: Harold Farrenkopf <[EMAIL PROTECTED]> >Date: 2007/07/26 Thu PM 01:50:26 CDT >To: [email protected] >Subject: [Repeater-Builder] Re: Coax length between added cavity and duplexer > >What are the frequencies of your repeater and the frequencies on the >nearby antenna???? > >What are the radios used on the nearby antenna? > >Important information in determining the problem - I had one source of >noise caused by a Mastr III that had a spur of considerable strength >at 12.8MHz down from the transmitter carrier - synthesizer oscillator! >It was received with the correct transmitter modulation as the carrier >frequency and a pass on it or a notch at -12.8 MHz solved our problem. > The level of the emission was within spec of the Mastr 3 but was >still too strong for our antenna at 500' away. > >What is the configuration of their filters? > >4' horizontal separation is not much at all so filters should be >designed to all the frequencies used to work together. > >Then, it only takes one transmitter to cause noise in an antenna if >the antenna is "noisy". > >What does the interference sound like? > >Harold, VA3HF > >--- In [email protected], Ken Arck <[EMAIL PROTECTED]> wrote: >> >> At 11:06 AM 7/26/2007, you wrote: >> >> >> >> Intermod means there is mixing in YOUR PA with some outside RF energy. >> >> <----I should probably clarify that "intermod" is an often misused >> term that has become a generic terms used to describe just about any >> type of received interference. Ya know, kinda like Klenex has become >> the name for any tissue. >> >> Intermod is a very specific type of phenomenon and for accuracy, >> should only be used to describe intermodulation issues and not mixes, >> adjacent channel interference, etc. >> >> (more of my 2 cents) >> >> Ken >> > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
