Your duplexer is spec for the frequency it just has too much loss. First you need to tune each can independent of the harness and tune the pass and then check the loop position. My bet is that it is set for max coupling. I would tune for .8db loss per can if you can measure that with your service monitor. You can achieve 90+db between tx and rx notch if you run the loop coupling a bit tighter than the .75db that is recommended. Here is the tuning manual for the duplexer.
Mike Mullarkey K7PFJ _____ From: [email protected] [mailto:[email protected]] On Behalf Of kb0nly Sent: Saturday, October 03, 2009 10:45 PM To: [email protected] Subject: [Repeater-Builder] TXRX Duplexer Loss is HIGH?? I have a TX-RX model 28-37-02A 144-174 Mhz duplexer, its rated for .5 Mhz at 400w, with an insertion loss of 1.5dB. Problem is we are measuring 3.0dB of loss PER SIDE, so 1.5dB of loss PER cavity?? Any idea what the heck is wrong here? We tuned the bandpass and reject, and its working other than being VERY LOSSY. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.420 / Virus Database: 270.14.3/2411 - Release Date: 10/03/09 18:34:00
