Wire skirts are also used to detune cellular and two-way towers, and power poles, when they are located near an AM broadcast station and would otherwise re-radiate a significant amount of RF and distort the radiation pattern of the station.
Steve WD8DAS sbjohns...@aol.com http://www.wd8das.net/ ----------------------------------------------------- Radio is your best entertainment value. ----------------------------------------------------- -----Original Message----- From: JACK C. SHUTT <w...@verizon.net> To: Discussion of AM Radio in the Amateur Service <amradio@mailman.qth.net> Sent: Mon, 12 Jan 2009 11:30 am Subject: Re: [AMRadio] 160 meter antenna Hi Robert, We have several of those wireless towers and monopoles around here, as well Those side wires are safety cables that climbers can clip on to with fall-arresting lanyards and harnesses, they are not radiators. Anyway, the folded unipole is a worthwhile antenna to try. I have had excellent results with an inverted L running up the side of my 80' tower and the "horizontal" portion sloping out to a tree. The "L' perhaps looks more like a vee with one short leg. Total length is about 135 ft. I use a coil and capacitor parallel network at the base of the tower feeding the end of the antenna wire then coax back to the shack. As always, a good radial system really helps. 73, Jack, W9GT --- On Mon, 1/12/09, robertchar...@att.net <robertchar...@att.net> wrote: From: robertchar...@att.net <robertchar...@att.net> Subject: Re: [AMRadio] 160 meter antenna To: cozy...@yahoo.com, "Discussion of AM Radio in the Amateur Service" <amradio@mailman.qth.net> Date: Monday, January 12, 2009, 7:23 AM Neal. Thanks for the link on building the Unipole. I had worked for Sprint for some time and I noticed they were using that same concept on many of their towers. The link was exceptionally helpful -------------- Original message from neal Newman <cozy...@yahoo.com>: -------------- > Jim you only need 50 feet of verticle space. > why not just build yourself a Folded Unipole antenna if you Dont know how. Ask. its really easy. Just Run 3 lengths of #12 wire or if you have it #6 wire. short them up at around the 50 foot point and use 1" PVC > Tubing as Insulators with clamps Down the side of the Tower. > at the bottom Each wire is isolated with PVC from the Tower. > BTW Each wire should be about 12" or more off the tower. then Tie all 3 wires together with a ring of #12 and take that as the Lead to the antenna tuner. Run at Least 4 ground radials 50 feet long If you can get > the space make them 120 feet... > and you will have a Killer 160 antenna. if not make an inverted L Run a wire thats 130 feet long. as far vertically as > you can then run the rest out horizontally... again you need at least 4 ground radials.... the unipole is what we use for > Broadcast stations when we are tight for height or space on a grounded Tower. > > Neal-KA2CAF > CE- WTTM/WHWH/WJDM/WIBG/WFYL > > > --- On Sun, 1/11/09, Jim Miller WB5OXQ in Waco wrote: > > > From: Jim Miller WB5OXQ in Waco > > Subject: [AMRadio] 160 meter antenna > > To: "Discussion of AM Radio in the Amateur Service" > > Date: Sunday, January 11, 2009, 11:28 PM > > I always wanted to try am on 160 but like most do not have > > enough room for a full size antenna, so, > > I am considering building a 160 meter antenna at our > > clubhouse because there is a 80' tower there and over an > > acre of land to spread out a 1/2 wave dipole. Question is; > > 1 Is a 1/2 wave wire dipole the best antenna for the band > > considering there is room for it. > > 2 Is 80' high enough for the center of the inverted V? > > 3 How high do the ends need to be off of the ground? > > 4 Should I feed it with coax or ladder line to the 10' > > level (or other) then a balun to coax to the tuner (coax is > > the only acceptable line into the shack)? The shack is a > > metal building 30X60' and directly below the tower. > > There is no way to get ladder line to the operating position > > since all cables have to run through a 3" conduit for > > at least 30'. > > > > The tower is a free standing commercial tower made of 4 > > 20' sections bolted together with a 2 meter and a 440mhz > > antenna at the top, all ham antennas. > > > > Thanks for any advice. Jim > > wb5oxq______________________________________________________________ > > Our Main Website: http://www.amfone.net > > AMRadio mailing list > > Searchable Archives: > > http://www.mail-archive.com/amradio@mailman.qth.net/ > > List Rules (must read!): http://w5ami.net/amradiofaq.html > > List Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > To unsubscribe, send an email to > > amradio-requ...@mailman.qth.net with > > the word unsubscribe in the message body. > > > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body.
