Hi Curt, Yes, that is the way I recall seeing the Dual Band antenna in the old DB products catalog. Have you tried checking the upper and lower halves to see what kind of SWR you have at the operating freq. ?? If it is convient, measure the end to end length of the upper and lower dipoles. The UHF diploes should be about 11-3/16" for the 450-470 MHz. The VHF dipoles should be 37" for 138-150 or 34-3/16" for 150-160 MHz. 155-165 MHz is 33-3/4" and 164-174 MHz is 31-3/4".
For some reason the UHF 450 -470 versions are very broad banded but the VHF versions seem to be more critical pobably due to the harness construction more then the dipole length. Thanks for the input. Doug N3DAB ===================================================================== --- In [email protected], Curt Seaton <seat...@...> wrote: > > Good day Doug. I have a DB dual band antenna similar to what you are > describing, it has 4 folded dipoles for two meters, and 8 folded dipoles > for 440. These are two on each side of the pipe for two meters and four > on each side of the pipe for 440. The diameter of the pipe is slightly > smaller for the 440 section. The exact model number is not readable > (scraped during mounting or dismounting) but it sounds like what you are > looking for. IF this is the same as you desire, mine does have TWO > different feed lines coming down to connect to your VHF and UHF radio > systems. The pipes are concentric with a wedge shaped mount and held in > final position with gravity and hose clamps. Keep us all posted on your > endeavors as we are looking for the same scenario for D star here.... > starting with the B module and adding C later... gotta recover > financially first... > > 73 > > Curt > W1FSM > > n3dab wrote: > > I know DB made a dual band 150/450 folded dipole antenna (bottom half was > > either a DB-222 or the bottom half of a DB-304 and the top half was a DB408 > > or top half of a DB-420), which is no longer available. Does anyone recall > > whether it was fed with one feed line or two ? I think it was 2 but, I > > can't recall the dipole configuration (singles on opposite sides going up, > > or pairs at each level). > > > > I would like to combine a DB-224E (138 -150) with a DB-408 or DB-420 > > (450-470) on a single mast, or split the antennas at the mid point and make > > 2 antennas with the VHF on the bottom and the UHF on the top, and the > > reverse on the second antenna. Has anyone tried this ? What were the > > results ? The numder of feed lines (1 or 2) to the antenna is not an issue > > at this time. > > > > The combined antenna would be for a 2 Mtr./440 D-Star application becuase > > of limited tower space available. > > > > Comments appreciated > > > > Doug N3DAB > > > > > > > > ------------------------------------ > > > > > > > > Yahoo! Groups Links > > > > > > > > > > >
