Here is the latest. I terminated the cable at the antenna with a dummy load and no desense. I hooked back up to the antenna and if listen to the receiver with the squelch open I hear a buzz in the background of the receiver white noise audio in addition to desense which doesn't show up when terminated. Checking the swr I have less than 1/2 watt reflected with about 80 forward. The offset for this receiver is 1.7 Mhz by the way. If I take a 1/4 wave mag mount antenna that I have sitting on top of the duplexer cabinet and plug it directly into the receiver I hear no buzz or desense. This tells me something is going on with the antenna and coming back the line. Is it time to put in some hardline?
Tom / KA1NVZ -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Thursday, October 02, 2008 8:47 PM To: [email protected] Subject: Re: [Repeater-Builder] LMR-400 Cable At 10/2/2008 05:41, you wrote: >Hello Tom, > >I think that the clue here is that you had desense with both the RG-213 >and the LMR-400. My guess would be that there is some mismatch between >the antenna and the duplexer. The duplexer may be tuned for a 50 >resistive ohm load, but the antenna system is presenting some other >impedance/reactance. Neither RG-213 nor LMR400 are suitable for duplex use, so it's quite likely that both were the source of the desense. Bob NO6B
