Use a high quality, low loss coax if you have a long way to run your feedline. In my case, I only needed 15 feet of coax so I used RG-8/U coax. This is not normally recommended, but with the feedline this short there is less than 1 db loss. The dimensions for the loop are dependent on the velocity factor of the coax used. Connect the coaxial balun to the feedpoint of the turnstile antenna, as shown in the drawing above.
|Vel. Factor 0.66
||Vel. Factor 0.78
I am very pleased with the performance of this antenna. Because I did not need the added expense of an AZ/EL rotor, I felt justified in purchasing a Mirage preamplifier. Even without the preamplifier, the MIR spacecraft, and ISS are full quieting in my receiver when they are about 20 deg. or higher in the sky. By adding the preamplifier, they are full scale on the S-meter at about 5-10 deg. above the horizon.
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