Can you receive through a circulator without heavy losses? I've never tried it...
----- Original Message ----- From: David To: [email protected] Sent: Monday, November 02, 2009 1:31 PM Subject: [Repeater-Builder] Re: Weird Interference between APRS and 2-M repeater help needed First of all you do not have enough isolation between antennas with only two wavelenghts horizonal seperation. A single bandpass cavity will not be enough. I would try 2 bandpass/bandreject cavities. Reject set for the TX freq and the other set for the RX freq. I believe that RF from your repeater is exciting the RF amp in your aprs tranceiver, see if the problem is still present with the aprs hooked up to the antenna but with your power supply disconnected. Most people used a simple mobile for aprs which creates alot of headaches where several transmitters are used. They just dont have the filtering needed for this application. You should also use a circulator on your aprs radio. This will help keep RF out of your aprs transmitter. David Epley, N9CZV Winchester, In .
