++++++++++++++++++ From: "Stuart Rohre" To: , "elecraft" Subject: Re: [Elecraft] Antenna Date: Tue, 5 Nov 2002 18:41:08 -0600 Hi Earl, My comments about galavanized wire antennas I have used being lossy was in the original query context of combined receiving and transmitting antennas. Of course, the Beverage receiving antenna is a wave antenna, and the loss of galvanized distributes the needed terminating resistance throughout the wire slowing the wave. I have a buddy here who has numerous Beverages for 80/160 (big acreage) he and ON4UN have similar set ups. Will have to ask him if he considered galvanized. I have up to this point been thinking his were copper. Good suggestion, thanks, Stuart K5KVH ++++++++++++++ To: rohre at arlut.utexas.edu, elecraft at mailman.qth.net Date: Tue, 5 Nov 2002 17:09:20 -0800 Subject: Re: [Elecraft] Antenna From: k6se at juno.com Stuart, K5KVH wrote: "Of course, the Beverage receiving antenna is a wave antenna, and the loss of galvanized distributes the needed terminating resistance throughout the wire slowing the wave." ========== Perhaps that explains why the termination resistance for my Beverages is much less than others have found on theirs. To determine the correct termination resistance value, I applied about one watt of power at 1830 kHz to my 1100' Beverage and walked the wire with a field strength meter. With the correct value of resistance, the field strength along the antenna had no peaks or nulls, however it did gradually get smaller due to wire loss and radiation loss as I walked toward the terminated end. The correct value of resistor in my case was about 300 ohms (7' high Beverage over desert soil). The theory behind the improved F/B ratio for the galvanized steel Beverage is that the signal from the reverse (unwanted) direction must travel down the lossy wire twice to reach the receiver -- once toward the terminated end, and then whatever signal is reflected from the termination must travel down the wire again toward the receiver. Signals coming from the forward (desired) direction must travel down the lossy wire only once. 73, de Earl, K6SE ++++++++++++++++