At 8/29/2008 09:41, you wrote: >A number of years ago, the packet operations here were able to get three >systems placed on cell sites. Each system consisted of a 440 MHz >full-duplex bit-regenerative 9600 bps packet repeater, and a 146 MHz 1200 >baud simplex digipeater/gateway. All three systems were using X50A >antennas, professionally installed, on the cell towers. We noticed that >when the 146 MHz transmitter was active the 440 MHz repeater experienced >desense that it didn't when the 146 MHz transmitter wasn't active. When the >same test was performed using a dummy load, we didn't have the problem. I >attributed this to IM generation in the antenna, although in further >consideration, there are some other possibilities - IMG on the tower and/or >in the lighting protector. All three systems experienced this, although to >varying degrees. Not a scientific result, but might be a reason to not use >a dual-band antenna on both bands. > >73 > >Bob, KD7NM
Not too long ago I installed a TRAM 1480 with the following connected to it: 2M TX, 2M RX (repeater) 445 TX, 440 RX (repeater) 420 TX, 430 RX (duplex link) All running at the same time. No desense. Bob NO6B >PS: My first post to the group - joined yesterday > >-----Original Message----- >From: Repeater-Builder@yahoogroups.com >[mailto:[EMAIL PROTECTED] On Behalf Of John W. Springman III >- KB3AWQ >Sent: Friday, August 29, 2008 9:12 AM >To: Repeater-Builder@yahoogroups.com >Subject: [Repeater-Builder] Re: Diamond X-50 NA > >I use the X50A (same thing just N type connector) on the W3AHS-R repeater >here in Williamsport, PA. I have used it since 2001 with no problems, in >fact I have 2 of them up there and the 440 Link radio also shares it and >have not had any problems. It is mounted on the roof of the high school >which sit on top of a hill about 1000 ft. >elev. I know another guy who has used it for an APRS digi up on the 2,000 >ft Williamsport Bald Eagle mountain even before that and it is still >holding. As far as the gain. Yeah its a little low but for UHF its a little >higher. I have talked mobile to Laporte, base stations in Hazleton, mobile >to Mill Hall and even on Route 80 at the Clinton/Centre County line and >about 20 miles to the south (good ol 2000 ft mountain in the way). I guess >you can see what I think of it. > >73 >John KB3AWQ > > > > Anyone have any opinions on the Diamond X-50NA? I have an application > > to use it for a simple repeater on UHF. > > > > > >------------------------------------ > > > >Yahoo! Groups Links > > > > > > >------------------------------------ > > > >Yahoo! Groups Links > > >
