----- Original Message ----- From: "Tim Goodrich" <[email protected]> To: <[email protected]> Sent: Sunday, October 11, 2009 10:51 PM Subject: [amsat-bb] accidental RF into wrong cable of Arrow=bad duplexer?
> I am an owner of a 2m/70cm LEO satellite antenna with duplexer in the > handle. Sometimes, I operate full duplex (two radios) and bypass the > duplexer by attaching my own cables to the separate parts of the antenna (1 > radio for 2m, 1 radio for 70cm). In the course of rushing to catch a > satellite pass, I mixed up my connections and accidentally transmitted (5 > watts) into one of the arrow antenna cables, causing RF to feed backwards > into the duplexer. > > > Recently, I have noticed decreased performance (poor reception, lower S/N, > even on AO-51 when in the past it was full quieting) and am trying to > ascertain if it could have anything to do with my mistake of feeding RF in > the wrong direction into the duplexer. Could my mistake cause this problem? > > Thanks, > > Tim > > KI6VBY > > Hi Tim, KI6VBY If I well understand you connected the VHF antenna to the UHF connector of your duplexer and the UHF antenna to the VHF connector of your duplexer while transmitting by mistake. A duplexer is essentially a low-pass filter at VHF and a high-pass filter at UHF having in the middle the common connector going to a VHF/UHF tranceiver. If you reverse the antennas at the output of the above duplexer the only effect will be a very high VSWR in both bands VHF and UHF but no damage will involve the receivers. Best 73" de i8CVS Domenico _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
