Thanks i found out its a Andrew dB224 - 155-165mhz, i was hoping it would be in the 145mhz - 2 meter ham band range but it seems you cant adjust this type of antenna.
--- In [email protected], "skipp025" <[EMAIL PROTECTED]> wrote: > > > > The characteristic impedance of a folded dipole is 300 ohms. > > Depends on who you ask really. The impedance of what most people > call a classic folded dipole is about 300 ohms. But measure the > various dipoles by Decibel and Sinclair you'll probably find they > are not all standard size dipoles. > > What Decibel does to match their dipole arrays is nothing like the > method used by Sinclair. > > cheers, > skipp > > > 4 of them, fed in-phase, will present an impedance of 75 ohms at the > > feedpoint of the phasing harness, which will present an acceptable > > 1.5:1 SWR to a 50-ohm transmitter. As Nate mentioned, some > > manufacturers build the phasing harness with different impedances of > > coax to transform the antenna array's impedance to 50 ohms. > > > > As far as frequency goes, if you're saying that the length of an > > element, from the center of the top bend to the center of the bottom > > bend is 34 inches, it's definitely a high-band antenna. The larger > > the element tubing diameter, the broader the frequency range the > > antenna will cover, so you may get that to perform acceptably at 2 > > meters. See the construction article on the Repeater Builder website > > at www.repeater-builder.com/projects/exposeddipole.html - it's > > pretty much the antenna you have. > > > > George, KA3HSW / WQGJ413 > > >
