I'd suggest using four if you have the tower real estate. Adjust each element individually on the tower up in the clear (not necessarily in the final location, but away from obstructions).
I don't know how the harness was designed for three elements, but making one for four is easy. Each pigtail from the element must be the same length. Two elements combine with a tee, then a 35-ohm 1/4 wave matching section is needed. Do this for both halves of the antenna. Then take two equal lengths of 50-ohm cable to a final tee, then another 35-ohm matching section. From there it's 50-ohms. Chuck WB2EDV ----- Original Message ----- From: "NORM KNAPP" <nkn...@twowayradio.net> To: <Repeater-Builder@yahoogroups.com> Sent: Monday, August 30, 2010 11:51 AM Subject: [Repeater-Builder] DB212-3 > Took down a set of DB212-3 dipoles in good shape with harness. I want to > use them on 6m for a repeater antenna. I also want to add one additional > dipole. I guess I will need to modify the harness and the dipoles as they > are marked for 35.960 mhz.... > I will be mounting all four (or 3) on one leg of a tower that is 4 feet on > a face. Is it worth my while to go for the 4th dippole? The loops are 155 > inches from tip to tip now. Looks like they need to be about 105 inches. > Anyone with any tips, pointers or advise? > Thanks.... >
