137 MHZ QHF Quadrafilar APT Antenna
- This version of the 135mHz quadrafilar antenna for APT reception is an adaptation from Bill Sykes and Bob Cobey's article Taming the QFH which appeared in the March 1997 RIG magazine.
Quadrafilar Helix antenna for 436 Mhz
- This is an antenna that author just built. Was intend for receiving the AO-27 downlink (at 436.800 +/- doppler). It is built with right hand circular polarization, and the gain is supposed to be in the neighborhood of 3 DB.
Quad antenna calculatorupdated
- To get the dimensions for your quad, all you have to do is type in the center frequency of the range where you talk, or the frequency you use most and then click the Calculate button.
3 EL Quad Designer
- This DOS program will figure the wire sizes for a 3 element quad and will also give you the distance from the center of the boom to drill your holes for mounting the wire on the spider. it also gives you the length of the 4 quarter wave lengths of wire in case you would like to figure the spreader drill points yourself.