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 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
