We have done this successfully here on a tower with 10' sides and 4.5" dia legs. A single DB224 close mounted or about 3' out on one side of the tower had a very strong null in the pattern caused by the tower.
In our case we mounted close mounted a DB228 on a leg pointed straight out from the apex of the triangle towards the major population area and put a DB224 on one of the other legs pointed 180 degrees away from the DB228 which made it perpendicular to the face of the tower or base of the triangle. The antennas are fed in phase using a power divider. The results have shown a very omni directional pattern if there are any nulls they do not seem to be significant in size or in a populated area. With the antennas close mounted, the tower seems to effectively shadow each antenna from the other so that there is minimal interaction between the two antennas. John Lock KF0M Wichita KS kf0m at arrl dot net > -----Original Message----- > From: [email protected] > [mailto:[EMAIL PROTECTED] Behalf Of kc4fwc > Sent: Monday, August 15, 2005 6:59 PM > To: [email protected] > Subject: [Repeater-Builder] How about dual DB-224's ?? > > > I happen to have two DB-224's that are identical, same phasing harness, > connector, etc. What if one was to put elements all in one line, and > at the exact same height, mount one antenna on the north side of the > tower (mounted directly to tower leg with elements pointed straight > ahead) and mount the other directly on south side of the tower in the > same manner, and feed with power divider or a tee connector with odd > 1/4 length of 35 ohm for matching purposes? If the antennas are fed > exactly in phase, that is. I understand about receiving signals 180 > degrees out of phase in the coverage area, but wouldn't this > configuration be similar to a pair of elements on a DB-420? Would this > configuration serve as more omni-directional? > > > 73, KC4FWC > > > > > > > > > > Yahoo! Groups Links > > > > > > > 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/
