On 3/26/2012 10:19 AM, Reed Bumgarner wrote: > Page 9 of the manual seems to say that creating a ground for the KX3 is > necessary in all cases. Is this really true when you're using a Buddipole, > Yo-Yo dipole or any dipole fed with coax?
This has nothing to do with the radio, but rather comes down to a matter of antenna fundamentals. First, any antenna needs an earth ground for lightning safety. Second, to function effectively as an antenna, any "single-ended" antenna that looks like a long wire needs some sort of counterpoise to carry the return current (and serve as a return for the electric and magnetic fields). A typical mobile antenna, most verticals, and a wire thrown into a tree all fall into this category. When the rig is tied to ground via the AC power supply and ground rods associated with the shack, that wiring and connection functions as a counterpoise of sorts. When an antenna is mounted on a vehicle and the coax shield bonded to the body, the body acts as a counterpoise. When you use a rubber duck on a VHF or UHF talkie, your body, capacity-coupled via your hand to the talkie, functions as a counterpoise. When operating battery portable with a rig like a KX3, a good practice would be to carry lengths of #22 wire that are a bit shorter than a quarter wave on the frequencies where you plan to operate, and that can be laid out on the ground around you to serve as a counterpoise. K2AV has also written about a "folded counterpoise" system that you can put together that is more compact than simple wires. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
