145 & 435mhz 5 element Circular Polarity Antennas
Re-manufactured from 2 Cushcraft A270-10S dual band antennas
From articles in ARRL publications I have tried to make circular polarized single band satellite antennas from 2 dual-band vertically polarized antennas. Some coax, "N" connectors, "T" connectors, coaxial phasing lengths and misc. hardware.
I off-set the element spacing 1.5" and 90 degrees, drilled holes and assembled the elements. Coaxial lengths computed and fitted with "N" connectors and joined to "N" type "T" adaptors will hopefully make it somewhat circular in polarity.
Each antenna section is being tuned and tested as this Web page is being written. If it seems to work, additional director elements may be added for increased gain. The need for low wind resistance is important, as there are often high winds at this location. The antennas that share a common boom will be connected, and tuning tested again. It may be a few weeks before the antennas will be fully tested.
A fixed elevation of approxiamately 30 degrees is achieved by an adaptor plate drilled and equipted with "U" bolts in the appropriate places.
A weather-resistant relay box for switching the Egg Beaters and Beams is being planned to take advantage of the characteristics of both antennas during the passes.
UPDATE: The 435 antenna is up on the rotor for testing at fixed elevation of about 15 degrees. A remote antenna switchbox with 435 rx pre-amp inside is under construction to switch between eggbeater and RHCP Beam.(3/5/98)
435 Antenna and elevation adaptor under test
Last Updated: March 05, 1998