The yard is about 160 feet on all 3 sides, and is shaped just like a slice of pizza. The house (brick ranch) sits half way, the front is a street (crust).
There are a lot of trees, but most are close to the house or lower. There is a big oak at the tip of the slice, but that is only going to get me another 5 feet, and its not as good of a support as the cedar. The wire would be in the branches, the cedar is compact... I don't want to put anything on the roof, the chimney wont support anything, and its off to the side. I know the way to go is to put up as much wire as I can and feed it with open wire line into a tuner, but I don't want RF in the shack, or have to tune up an antenna when I switch between 80 and 40. I have separate stations for 80 and 40, so no tune up needed there. I once tried the open wire line into the heathkit antenna tuner, and it just smoked the crappy balun, I would have to build a real balanced tuner. Tricky to build one that is shielded and adjustable... Brett -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of W5OMR/Geoff Sent: Monday, December 05, 2005 8:32 PM To: Discussion of AM Radio Subject: Re: [AMRadio] Valiant and Loop progress Brett gazdzinski wrote: >While on the subject of antennas, I wonder if anyone knows of a way >to do what I want to do. >I had a resonant 80 meter dipole above the house, the length was only >about 90 feet, so I had loading coils about 3/4 of the way out from the >center. >That worked ok for years, but the coax went bad at the feed point, and >while the antenna seemed to work ok, I had a bit of RF in the house, since >it was lengthwise over the entire house. > >I have a resonant 40 meter dipole that runs at right angles to the house, >and most of it is over the back yard, no RF in the house. > >I likely have about 90 feet there also, if I stay out of the trees. > >I would like to have one antenna that is resonant on 80 and 40 meters >without an antenna tuner, that fits in the 90 foot space. > >A trap dipole would be nice, but I have never found anything that holds up >to >AM at any but the lowest power levels. > >I normally run about 300 watts carrier on 40 and 600 watts carrier on 80. > >I made the mistake of trying one of those B+W all band folded dipoles, the >lowest >swr I could get about 4 to 1, maybe because of the close trees. >They are also only good for low power on AM. > >The next experiment was as much wire as I could fit above the house, about >42 >feet each side, fed with open wire line for about 10 feet, then to coax. >The first test showed the swr way off, so I put the antenna tuner on, and it > >started arcing. I added another 10 feet of coax and everything seemed to >work ok, >but a lot of RF in the shack, and I bet I loose power in the coax with a >high swr. > >I don't want to have to fool with an antenna tuner when changing bands, and >would rather not use one at all. > >The best bet would be some sort of antenna where the 40 meter dipole is, but >I cant think of anything that would do what I want it to do. > >The property is in the shape of a pizza slice, the point being my back yard. >half way up the sides I have a medium size oak tree, and a 36 foot mast on >the other side >that is against the garage. >Close to the tip of the slice, I have a real nice cedar tree that is like a >mast, >a very good antenna support. >Out front, away from the crust is another medium size oak. >The 40 meter dipole runs from that to the cedar, and is up about 40 feet. > >Anyone got any ideas, other than ordering a pizza? > need just a little more input, Brett... what's the length of the pizza slice, and how wide is it, at the crust? -Geoff W5OMR ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
