> I believe you are right. Simplex is difficult with a circulater. David Epley, N9CZV
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 > > > . > >
