Derek, First and foremost, choose an omnidirectional antenna if the repeater is centrally located, but consider an offset pattern antenna if the repeater is at one side or end of the desired coverage area. Second, don't go overboard on the antenna gain, lest the pattern "go over the heads" of your intended users. Dipole antennas often perform much better than collinear fiberglass antennas in this regard. It is an excellent idea to use the lowest-loss feedline you can afford, and if 1.625" Heliaz is available, use it. My rule of thumb is to use whatever feedline has less than 1.0 dB of loss at the highest frequency used by the repeater.
73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Derek Sent: Friday, November 23, 2007 2:55 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Repeater Antenna Choice I'm looking for input on what kind of antenna to use for several 440 MHz amateur repeaters. Background: Suburban area surrounding metropolitan city of about 700,000. HAGL for antennas range from 260' to 320' on 400' and 500' towers. I'm looking to maximize mobile and portable input, even possibly looking to use 1-5/8" heliax as I recently installed this size hardline on my repeater and have been very satisfied with the results. I've used the DB-408 antenna and am happy with its performance, but am wondering about significant difference in using a DB-420 for future repeaters. Also considering the RFS 1151 (Tessco # 435830) fiberglass antenna. It is tuned for 440-450 MHz and has 8dB gain, but I've heard some say fiberglass is not the way to go for repeaters. Any thoughts are appreciated. Derek
