From owner-barc-list@netcom.com Wed Jul 31 02:32:40 1996 Date: Tue, 30 Jul 1996 21:32:40 -0500 (EST) Subject: Eggbeater antenna plans To: barc-list@netcom.com Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT I found these plans over on the net. There was considerable interest in them at a previous BARC meeting, so I am posting them to the list. I haven't built it either, but plan to when I get a chance. 73, /mike n1ist@netcom.com Begin included article: Hi Folks I got these plans from someone via E-Mail. I haven't built this antenna yet, so I have no idea how well it will perform. (Please note that when the plans refer to rg-93 coax, I believe they mean RG-62.) Please, If you build this antenna I would love a quick E-Mail to see how you made out! Begin Pasted Text: ------------------------------------ Date sent: Wed, 14 Jun 95 12:53:10 CDT From: harper@huntsville.sparta.com (Christie Harper) To: dsantoro@pipeline.com Subject: eggbeater For a more omnidirectional antenna you might try what is known as an "eggbeater" there are commercial versions available for $110 or you can make one for about $5. the eggbeater is comprised of two full wave loops placed perpendicular to each other and driven 90 degrees out of phase. this gives the antenna a horizontal component along the horizon and a circular component overhead. looking at the antenna from the top it would look like; | | | | ----------+---------- | | | | Use a piece of pvc pipe as the mast. Make two full wave loops (length = 299.8/F (Mhz) Meters) using #12 or heavier wire. A full wave loop has a "resistance" of about 100 ohms so resonate the loop at the desired frequency by doing the following; use a quarter wave 75 ohm matching line (50-100 ohms). Cut the loop one or two inches longer than calculated and keep pruning to resonance. drill holes in the pvc to pass the loop (NOTE insure that the loops DO NOT touch at the top or bottom. Phasing harness..... need a 1/4 wavelength piece of 93 ohm coax length = 0.25*(velocity factor)*299.8/Freq (Mhz). Velocity factor is available in most handbooks (coax is RG-93). ---- braid ____ center conductor |----| |---loop 1 |-----loop 2 | | RG-58 (50ohm) | | | | -----------------------------|---------------------| | | _____________________________ _____________________ | | | RG-93 (93 ohm) | | | | | |----| | | favorite connector An easy to mount the phasing line is to take a small piece of circuit board (radio shack) and drill three holes in it and attach cable as follows. +---------+ +---------------loop 2 loop1------| | | ( * ) ( * ) ( * ) 50 ohm 93 ohm 93 ohm solder all shields to the circuit board. connect short jumpers from the circuit board to the other sides of the loops. Based on homebrew work of W3PM (Gene Marcus) --------------------- Date: Sat, 03 May 1997 12:14:40 -0500 Reply-To: mmarcus@hiwaay.net To: wdr@world.std.com Subject: Re: Looking for 2M Eggbeater The egg-beater plans found at http://world.std.com/~wdr/eggbeater.txt contains a typo. The 93 ohm coax used as a phasing line is RG-62 not RG-93. 73 Gene Marcus W3PM GM4YRE Huntsville, AL mmarcus@hiwaay.net w3pm@amsat.org --------------------- From rpainter@execpc.com Tue May 6 01:16:00 1997 To: wdr@world.std.com Subject: Re: Looking for 2M Eggbeater Newsgroups: rec.radio.amateur.antenna : The only : magazine references I've found are to issues not currently held in : any nearby libraries, It is in the Radio Amateurs hanbook in the year 1976 and many others years prior. The turnstile and halo's are there too. 73! de N9GKH Ron