Date: Sat, 23 Jul 94 04:30:12 PDT From: Ham-Ant Mailing List and Newsgroup Errors-To: Ham-Ant-Errors@UCSD.Edu Reply-To: Ham-Ant@UCSD.Edu Precedence: Bulk Subject: Ham-Ant Digest V94 #235 To: Ham-Ant Ham-Ant Digest Sat, 23 Jul 94 Volume 94 : Issue 235 Today's Topics: Carrier-current antenna alternative Feedline next to 220V run ROHN tower info, please Send Replies or notes for publication to: Send subscription requests to: Problems you can't solve otherwise to brian@ucsd.edu. Archives of past issues of the Ham-Ant Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/ham-ant". We trust that readers are intelligent enough to realize that all text herein consists of personal comments and does not represent the official policies or positions of any party. Your mileage may vary. So there. ---------------------------------------------------------------------- Date: 22 Jul 1994 16:01:00 GMT From: ihnp4.ucsd.edu!agate!darkstar.UCSC.EDU!news.hal.COM!olivea!koriel!male.EBay.Sun.COM!uranium!raymonda@network.ucsd.edu Subject: Carrier-current antenna alternative To: ham-ant@ucsd.edu >Richard Branden Emmerson (rbe3@konichiwa.cc.columbia.edu) wrote: > >: If anyone knows how to set up a "carrier-current" antenna configuration or >: knows where any information on this topic can be found, I would be greatly >: appreciative. Either post on this group or email rbe3@columbia.edu with any >: information. Thanks! > >: Branden Emmerson >: rbe3@columbia.edu >: KE6EYW > Carrier current broadcast distribution is traditionally done at or below AM broadcast frequencies. The signal (say at 1 MHz) is inductively or capacitively coupled into a buildings AC power wiring. Receivers within the building can capacitively couple the signal off of the power line and receive it. If the signal strength is adequate, you don't even need to couple the receiver to the power line with coupling circuitry, but you can receive the signal if you are within a resonable distance from the wiring due to radiation. Normally this can be from 10 to several hundred feet. Also, other devices on the circuit (motors, appliances, lights, etc.) can soak up a lot of the RF and decrease the signal strength on the line. This technique is quite often used in college dorms to broadcast to the residents without going on the air and getting a license. The signal can also feed out of the building and to adjacent buildings, but if there is a transformer on the power pole between buildings, quite a bit of attenuation may result as they are pretty lossy at RF frequencies. There are FCC regulations on how you are allowed to use carrier current techniques. You also need to be careful on how you implement the coupling circuitry as your are messing with AC power circuitry. The X-10 home automation digital controller stuff utilizes carrier current techniques for device control. That's it in a nut shell. There is a whole lot more that could be said, but that should get you started. 73's, Ray WB6TPU ---------------------------------------------------------------------------- This response does not represent the official position of, or statement by, Sun Microsystems Incorporated. The above data is provided for informational purposes only. It is supplied without warranty of any kind. ---------------------------------------------------------------------------- /\ \\ \ \ \\ / / \/ / / Raymond E. Anderson / / \//\ Signal Integrity Engineer \//\ / / Sun Microsystems / / /\ / 2550 Garcia Ave. MS MIL04-16 / \\ \ Mountain View, CA 94043-1100 \ \\ \/ (408) 276-5224 (408) 956-0492 fax raymond.anderson@Sun.Com ------------------------------ Date: 22 Jul 1994 11:19:42 -0500 From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!europa.eng.gtefsd.com!news.msfc.nasa.gov!not-for-mail@network.ucsd.edu Subject: Feedline next to 220V run To: ham-ant@ucsd.edu MUENZLERK@uthscsa.EDU (Muenzler, Kevin) writes: >Tom Blatz (KC5HEG) writes: > You should have no problems running your RG8 next to your 220V line. >I am doing the same thing. I did place a small junction box at each end >with >a large toroid core at each end of the 220V line. I don't remember the >number >that I used but it is about 5 inches across and about 1.5 inches thick. I >put >three turns of the 220V line through the core at each end. This should take >care >of any RFI introduced. Since you will be running 2 meters and probably low >power, you shouldn't not need to do that. I am running a Yaesu FL-7000 amp >(about 600W) and RG8 and am having no problems. You shouldn't have to go to this length. The reason being the coax, if it is of good quality, is shieled. i.e. no RF in or out of the coax. So you don't really need the torroids, etc. Herb -- -------------------------------------------------------------------------------- W. Herb Sims sims@sauron.msfc.nasa.gov NASA/MSFC/EB56 sims@saruman.msfc.nasa.gov Huntsville, AL 35812 sims@galadriel.msfc.nasa.gov KU0C Voice (205) 544 8581 PP-ASEL-IA FAX (205) 544 7499 Find your dream, and never give up until you achieve it -------------------------------------------------------------------------------- -- -------------------------------------------------------------------------------- W. Herb Sims sims@sauron.msfc.nasa.gov NASA/MSFC/EB56 sims@saruman.msfc.nasa.gov Huntsville, AL 35812 sims@galadriel.msfc.nasa.gov KU0C Voice (205) 544 8581 PP-ASEL-IA FAX (205) 544 7499 Find your dream, and never give up until you achieve it -------------------------------------------------------------------------------- ------------------------------ Date: Fri, 22 Jul 1994 15:42:01 GMT From: netcomsv!netcom.com!slay@decwrl.dec.com Subject: ROHN tower info, please To: ham-ant@ucsd.edu Thanks to all for direct and posted replies. I have now contacted ROHN Mfg. directly. Many thanks again. 73 de Sandy slay@netcom.com ------------------------------ End of Ham-Ant Digest V94 #235 ******************************