That's exactly what the "Artificial Ground" does, George. When you have a ground wire going to a ground stake it makes a lousy RF ground, but it'll be a much worse one if the wire to the stake is more than a couple of feet long because the wire is an appreciable fraction of a wavelength at HF. If the same connecting wire goes to a wonderful multi-wire counterpoise, the effectiveness of the counterpoise is badly compromised if the connection to the rig isn't very short and direct. Using very broad straps for conductors helps, but they are impractical for many situations.
The "Artificial Ground" is simply a network to tune out the reactance in the connecting wire so the ground can act at maximum efficiency. It brings a distant ground "to the rig" electrically. As you said, you need a decent ground just the same, both for avoiding RF on the rig and for decent efficiency from a short (1/4 or less) end-fed antenna. But, sometimes, even a lousy ground like a stake in the soil is enough to eliminate the "RF on the Rig" problem, if the reactance of the connecting wire is tuned out. The "Artificial Ground" also allows "tuning" a simple counterpoise for maximum effectiveness on each band. That's how I use one with excellent results. It eliminates the need for a 1/4 counterpoise wave wire for each band in use. Ron AC7AC -----Original Message----- At the risk of seeming to rain upon the parade, let's keep in mind that the 931 can at most provide a low-impedance path to "ground." Whatever that "ground" happens to be is what determines the success or failure of using the 931.... ...the most effective way to place the equipment at zero rf potential is the "driven ground." This consists of a 1/4 wave length of wire with one end connected to what is decided to be the station "ground" point and the other end unconnected. The wire can lay on the shack floor. It will carry induced current and radiate and thus is a source of RFI. But the open end will assume a high r-f potential thereby driving the connected end to very near zero potential. A wire for each band can be used if needed. 73, George W5YR Fairview, TX [EMAIL PROTECTED] http://www.w5yr.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
