OK, I take it back. This antenna is not a dummy load EVERYWHERE. There
are some frequencies where it shows a resonance, although the resonances
are very sharp, and outside the resonant points, for frequencies above
14 MHz the SWR varies between 20 and 50 to 1. Below 14 MHz the SWR is
mostly >100 to 1, with the exception of 7 MHz where it dips to about 10
to 1, and 10 MHz where it dips to 50 to 1.
If you could match this without a huge loss, there are some frequencies
where the radiation angle is low, although the azimuth pattern is pretty
weird, and its performance is less than that of a dipole.
I'm still not sure that this is what Gordon has.
Jerry, K4SAV
K4SAV wrote:
>Gordon wrote:
>I have an 80M V dipole/sloper going from a fiberglass sidearm on my house
>tower at 40 ft to the back of my lot. The ends go to two 15ft towers with
>15ft masts on top along the back of the property line. They are about 20 ft
>apart and the wires go through insulators and then angle toward each other
>as they head to the ground where end insulators hold the ends with the help
>of some 5-50 parachute cord.
>
>I am having trouble visualizing this. Do you mean that the ends of this
>vee dipole are only 20 feet apart? You have both wires of the dipole
>folded back, running parallel to each other, with the ends 20 ft apart?
>You don't say what the length of the wires to the 30 ft supports are,
>but they can't be more than about 70 feet judging from the size of your
>lot. If this is what you have, it should be pretty much a dummy load on
>all bands. Does this resonate on any band?
>
>I have to be misinterpreting this. Typo somewhere?
>
>Jerry, K4SAV
>
>J. Gordon Beattie, Jr. wrote:
>
>
>
>>Hi Folks!
>>I have an 80M V dipole/sloper going from a fiberglass sidearm on my house
>>tower at 40 ft to the back of my lot. The ends go to two 15ft towers with
>>15ft masts on top along the back of the property line. They are about 20 ft
>>apart and the wires go through insulators and then angle toward each other
>>as they head to the ground where end insulators hold the ends with the help
>>of some 5-50 parachute cord.
>>This works OK on 40, but is mediocre at best. The other bands are also
>>poor.
>>
>>I can make changes, add new antennas even build a rectangle as originally
>>planned by adding a support across the house roof to complete the rectangle.
>>
>>I would even entertain verticals!
>>I am not really limited except with respect to the size of the lot. I also
>>have a LARGE collection of aluminum to make dipoles and verticals. A
>>tribander is probably not going to fit. Some combination of wire and
>>aluminum to cover HF bands and directions would be fine. Suggestions are
>>welcome!
>>
>>As further background, I have included a description of the lot, buildings
>>and towers.
>>
>>I have a 40x100 lot with a house that is 21 x 32 and 19ft from the street.
>>It has a driveway up one side leading to a garage that is in the back corner
>>of my lot.
>>There is also a sizeable deck behind the house.
>>The primary tower, a 45ft ROHN 25 with 23ft of masting is along side the
>>house in the driveway. This tower has an 144/222/446 MHz omni on top and a
>>KLM 50-52 yagi on it. I removed the other VHF antennas when I couldn't
>>control the bird population pooping on my cars and driveway.
>>
>>I have placed a second tower, an Alumna T-140 with 20ft of masting in the
>>back yard 26ft behind the house along side the garage. I'm planning to put
>>my 144 and 222 long-boom yagis on it. Anything longer or taller would have
>>to be added while the tower and mast is tilted toward the house so I could
>>add it to the top of the mast from the almost flat roof. To do that I
>>would need to extend my mast....I'm not sure that is a good idea given the
>>relatively high welded rotator shelf in the tower.
>>
>>As noted above, there are two light duty towers and masts, each about 30ft
>>tall holding the wires of my V-Dipole/sloper up along the back of the lot.
>>
>>Finally, in the middle of my roof is a 3.5 inch rotatable mast that extends
>>8ft above the roof. The bearings and rotator are in the corner walls of my
>>shack. I plan to put my 432, 903, 1296 and 2304 antennas on it. The idea
>>is to have short coaxes and have most of the bird perches (and bird poop) on
>>my lawn.
>>
>>73,
>>Gordon Beattie, W2TTT
>>201.314.6964
>>w2ttt@arrl.net
>>w2ttt@att.com
>>
>>
>>_______________________________________________
>>
>>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
>>questions and ask for Sherman, W2FLA.
>>
>>_______________________________________________
>>TowerTalk mailing list
>>TowerTalk@contesting.com
>>http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>>
>>
>>
>_______________________________________________
>
>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
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