I am not sure why an isolator would cause intermod. Usually there are not active or non-linear components in them and they are often used to prevent intermod by preventing outside signals from coming in thru the feedline into the transmitter.
In the past commerical sites would often require an isolator for this reason with strong transmitters close by. In better repeater equipment an isolator was built in. 73, ron, n9ee/r >From: Jeff DePolo <[EMAIL PROTECTED]> >Date: 2007/10/22 Mon PM 07:27:09 CDT >To: [email protected] >Subject: RE: RE: [Repeater-Builder] Re: duplexer isolation and reciever noise >budget > >> This isn't guessing - its called RESEARCH > >When I said guessing, I was talking about quantifying the performance of >your radios rather than guessing how much isolation you need. In other >words, make measurements to actually determine how much noise supression and >carrier attenuation you need using the actual frequencies involved. Once >you know how much isolation you truly need, then you can work backwards from >there to determine the filtering requirements. > >I still think using an isolator is going to cause you new problems with >respect to IM into your receivers unless you have adequate filtering between >the isolator and antenna, which I believe you have no way of acheiving if >I'm understanding your layout right (i.e. isolator is connected directly to >the antenna with nothing in between save for a harmonic filter). > > --- Jeff > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
