"Derek B. McIntyre" wrote: SNIP > I have acquired a Diamond X-500 which claims 8.3 dB on 144-148 MHz > and 11.5 dB on 440-450 MHz. The antenna is just over 17 feet tall, > making the gain claims ridiculous.. My guess is it's rated in dBi, > therefore, the claim may be a little closer to realistic.. 5 dBd on > 2M and 8 dBd on 440 is my guess.. SNIP
I think your guess is probably much closer to the truth. > I have heard people say that running dual banders in duplex mode on > both band can cause broadband noise, intermond, etc, often causing > either severe duplex noise or desence on the repeater unput. I have > often wondered has anyone had experience with these types of problems. I doubt that is true. I have 2 sites where I run the Comet GP-15 440/2m/6m antenna on repeaters for 2 meters & 440 Mhz. 75 watts out of the 2 meter duplexer & 45 watts out of the 440 duplexer thru about 60 feet of 7/8" heliax has performed well for years. As with any good installation, use QUALITY receivers & transmitters, QUALITY jumpers (like RG-214), and good pass/reject duplexers. I have been able to make these systems work WITH ARR GaAsFET pre-amps!!! (If there was a noise or intermod problem, the pre-amps wouldn't be working!!) Be prepared to put a pass can with sharp skirts on the receive side output of your duplexer. NOTE>> a quality receiver and transmitter basically dis-qualifies the following: Icom, Yeasu, Standard, Uniden, Kenwood, Motorola GM-300, Azden, Alinco. The following would be considered quality: GE Mastr Pro, GE Mastr II, GE Mastr Exec II (NOT the original Exec), GE Mastr III, Motorola Motrac, Motorola Micor, Motorola MSR. > > I have assembled the array and it feels like a wet noodle stick, > > pretty flimsey, but is rated at 90 MPH.. Some people say the joints > > work loose inside the antenna. Who can relate to this? I always pull my systems Comet antennas apart & solder the connections. Better yet, forget the Comet & Diamond antennas that have connections in the antenna. Get the Comet GP-15 from HRO for a little over $100, it is a one piece antenna (no connections) and has worked very well for me. Actually, it is best NOT to use Comet or Diamond antennas. But sometimes the situation dictates that you must. Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
