Tests run in 1965 by W0YBF with an underground doublet (it was buried about 2 feet below the surface of the soil but the wire was insulated from the surrounding earth by putting it inside a plastic pipe) showed that it was about 18 dB below an elevated dipole - about 3 "S-Units". Perhaps a wire ON the ground would be a bit better, especially if it was insulated.
Still 3 S-units isn't bad for a completely invisible antenna that, by definition, can't blow down in a storm<G>. And it picks up very little local QRN on receive. Many ops looking for a low QRN antenna in a noisy location simply throw a wire on the ground and get far better results than with a resonant wire up in the air. Underground and on-the-ground antennas date waaaaay back. There was on in the RSGB "T & R Bulletin" from February 1927 by C.H. Taggett, G6PG, who used a 60-foot rubber insulated wire buried 2-1/2 feet down. That one was end fed with the "feeder" passing through a length or rubber hose to the pipe-enclosed antenna. G6PG ran 8 watts into the antenna on 150 meters, 90 meters and 45 meters back in the 20's with contacts ranging out to about 1000 miles. Interestingly, in spite of the fact that the antenna was only 60 feet long, he found it to be very directional with most contacts within an angle of 30-degrees from the far end. My references mention underground antenna experiments going back to 1912. Later center-fed versions, such as W0YBF's, center-fed the antenna with a matching network in a plastic garbage can underground with the lid accessible from above so it could be opened for adjustments. I've used an on-the-ground antenna too, and gotten out with it... At least until I went outside to investigate why my ATU settings had changed so much and noted that it had fallen down from its supports<G>. Ron AC7AC -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, June 28, 2004 11:20 AM To: [email protected] Subject: Re: [Elecraft] A small FD experience In a message dated 6/28/2004 1:33:05 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: > I double-dare you to model this antenna in EZ-NEC, > Tom ;)... 73 de Jim, N2EY _______________________________________________ Elecraft mailing list Post to: [email protected] 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
