I have just this arrangement working for a 440 repeater and a 2 meter remote base. I took a DB-224 and added four bays of a DB antenna for 440 (never knew the part number) and put a two band duplexer at the antenna and ran a single feedline. A two band duplexer at the cabinet split out the 2 and 440 signals. This never worked very well, but works just fine now that I added a separate feed line for each antenna with no 2/440 duplexer used. I do not see any interaction between the two antennas, however I am sure that the 440 transmitter couples into the 2 meter receiver due to the third harmonic relationship. I have not seen any degradation on the 2 meter receive, however using GE Mastr Exec II radios. Power on 440 is limited to 20 watts.
73 - Jim W5ZIT -----Original Message----- From: [EMAIL PROTECTED] To: [email protected] Sent: Sat, 6 Jan 2007 3:48 PM Subject: [Repeater-Builder] dual band antenna I realize that from time-to-time this subject has come up: the want of a commercial-grade dual band antenna. The DB314 is one option that has been mentioned before, but the gain figures are not what we'd like them to be. And we'd really like to find something other than a multiple-section ham dual bander. Our ham club is wanting to add 440 capabilities to our current repeater site. The tower is a golfball-on-a-tee style water tower, and we are allowed only one mounting location. So we find ourselves in this same situation. We are currently using a commercial fiberglass stick on the low end of it's 2:1 curve for VHF and we are allowed to replace it with whatever we want to pay for. hi hi Has anyone ever tried 'interlacing' a DB224 and a DB408 or DB420(or similar) on a common mast? and use suitable diplexers at the top and bottom ends of the line? or would there be too much interaction between the bays, using that physical arrangement? or would it result in goofy patterns? Or is the DB314 the only workable method of doing this? and is it worth it at ~1200 bucks? Thanks. 73 Paul ________________________________________________________________________ Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.
