Amazing 75-Meter Hustler Dipole At AI1V |
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LARG HF Net Advisory de AI1V - Rick - Reston, Virginia On The Occasion Of The July 15, 2010 LARG Thursday Night HF SSB NET: |
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There are lots of "short" whips available. Some are expensive tunable screwdriver arrangements. Others are single band such as the Hamsticks.
I've always admired the Hustler mobile whip system. It consists of a rigid 54" mast and one of several available threaded "resonators" depending on the band used. I had a fairly complete system from many years ago and I took advantage of another one for sale on the LARG web site. I then got a "Rotatable Dipole Mount" from the Hamstick company (catalog #901, $19.95) and that completed my dipole kit. Several companies make these mounts and since the Hustler whips end in a 3/8" #24 thread, they are almost all compatible. They permit you to connect two whips back to back and have an SO-239 connector for the feedline. Love This Umbrella Prior to the drill, I put the system together and saw what the tuning range was. The antennas are tuned by extending or retracting a whip that extends out the end of the resonator. Below is a tuning chart for my system using 75 meter resonators. The measurement is from the tip of the whip to the top of the resonator body:
The Mounting and Feed I prefer the Hustler whips for two reasons. First of all, most other mobile whips for HF are either bottom loaded (coil at the bottom like most screwdriver antennas) or continuously loaded (antenna is just a long, loosely wound coil like the Hamsticks). The Hustler antennas are center loaded - the coil is significantly above the antenna feedpoint. I would need to study it more, but I believe that more current flows in the lower mast section of the center loaded whips than in the other approaches which means it can radiate better in some conditions (YMMV). The reason more manufacturers don't take this approach is that it is more mechanically challenging, with the lower mast having to support the resonator mass at a considerable lever arm. |
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