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Author Topic: 43 foot verticals  (Read 12320 times)
KE2TR
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Posts: 175




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« Reply #45 on: December 09, 2012, 10:46:48 AM »

In regard to testing the 43ft vertical on 40 I have down about 30 33ft radials and also a bunch of 18ft radials as well plus its tied to about 100ft of chain link fence. When I compared the two verticals on 40mtrs I used just one 1/4 wave vertical with 2 elevated radials, local qso's were not as big of a difference but on DX it showed up more when using the monoband vertical over the 43ft vertical. On 75mtrs the 30ft inverted L (this is a coaxial inverted L) has a lower noise floor and is an all around better antenna for both local and DX. Were the 43ft vertical shines is 20mtrs., I had up a 20mtr delta loop and it spanks that antenna on everything, maybe cause its 5/8 wave and according to theory 3db of gain, I don't know but its a real good antenna for that band. I am not saying that its a bad antenna but its a compromise just like trapped verticals and anytime you compare a monoband antenna to either trapped or 43ft vertical, the monobander will do better so its what you want in total system performance is the bottom line. Maybe if you just want one antenna at your qth it makes a good compromise antenna but above 17mtrs the take off angle gets a little on the high side but on the lower bands it makes for something that will get you on the bands with a decent signal. BTW all the antenna feedline's are with RG-213, no RG8X.
Jim
KE2TR
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W5DXP
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Posts: 3613


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« Reply #46 on: December 10, 2012, 05:36:41 AM »

Where the 43ft vertical shines is 20mtrs., I had up a 20mtr delta loop and it spanks that antenna on everything, ...

If that's a full-wave 20m vertical delta loop, it should beat the vertical broadside at most elevation angles (if it is as tall as the vertical).
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73, Cecil, www.w5dxp.com
The purpose of an antenna tuner is to increase the current through the radiation resistance at the antenna to the maximum available magnitude resulting in a radiated power of I2(RRAD) from the antenna.
K1DA
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Posts: 513




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« Reply #47 on: December 10, 2012, 08:37:34 AM »

With regards to the long radiator problem on the higher HF bands, has anyone considered putting a sliding ferrite suppressor ring on the vertical?

I can't claim this is original since I saw this in some forgotten antenna book, but it may be one way of stopping having to lower the whole tube.
Perhaps some sort of flagpole pulley arrangement on the top and a ferrite ring free to be hoisted up and down.

I am not an engineer, so I am only surmising this could act as a sliding suppressor trap, electrically shortening the antenna.
It may be totally wrong technically, but perhaps some of the genius antenna guru's could comment on this sliding ring's effect.

Another thing I saw was that if you move a capacity hat down near the feedpoint of a vertical, very little radiation will be above the hat.
If a suppressor ring is not practical, could a sliding capacity hat do the same thing?
 
I am pretty busy at the moment with my own antenna experiments/building, but I will try it when I have some free time.

73 - Rob
  HyGain used stubbs to decouple lengths of the antenna on the HyTower, which is 52 feet high.
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K0OD
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Posts: 2558




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« Reply #48 on: December 10, 2012, 08:46:13 AM »

Jim [KE2TR], I'm still trying to figure out where your A/B antenna tests were done. You've moved a number of times according to your online info. Was this the location, apparently on the tip of Long Island surrounded by ocean and a ton of aluminum shown in this picture?  Your info says you had a "3 element 40ty at 72' "
http://www.ezoom.net/images/lotsayagis.jpg

[sing along] "If everybody had an ocean across the U.S.A..."
« Last Edit: December 10, 2012, 09:07:59 AM by K0OD » Logged
KQ0C
Member

Posts: 25




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« Reply #49 on: December 10, 2012, 12:45:00 PM »

I use a wire 43 footer next to a wire 24 footer. I use the 43 on 20-30-40-80 and the shorter antenna on the higher bands. Feed both with ununs. My feedline SWRs don't run all that high so feed line losses are manageable. Both antennas share a semi-decent radial field.

A remote SGC auto-tuner would be more efficient but I run higher power than they can handle.

At a different QTH I have the heavy duty Zero Five 43-footer which I top load to be an 80 meter monobander. These are really built beautifully. I do guy mine with the guy ring provided with that version of the antenna. It sees 100 mph winds a lot and has been struck by lightning at least twice.

But if you have trees why not just run a wire vertical.

And incidentally, if you run an inverted V with the feed line coming down a tree trunk that is pretty invisible too.

« Last Edit: December 10, 2012, 12:48:16 PM by KQ0C » Logged
KE2TR
Member

Posts: 175




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« Reply #50 on: December 12, 2012, 08:01:19 AM »

That was two qth's ago back when I had my mini contest station and a small ton of yagi's on 1/3rd acre plot here on LI,NY, wish I had that station out here which is 15miles east of the old qth. Were I tested the 43ft against the 40mtr monoband vertical is my present qth, both qth's were are 5 miles inland from LI sound so I didn't get that extra 6db boost from a salt water qth. All I have up here is a pair of 40mtr verticals, the 43ft tuned for 20mtrs and a coaxial inverted L for 75mtrs, much lower profile then back then. When I had that station I was single so that kinda changes when you get married. That station was my dream shot and I am glad that I built it cause it played real well but its allot to take care of, now I keep it simple and easy.
The delta was at 35ft and I did take it down cause the vertical did as well if not better, the longer the dx path the better the vertical did over the delta.
Jim
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W5WSS
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Posts: 1744




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« Reply #51 on: December 12, 2012, 08:31:55 AM »

Kq0c I use three wire verticals 22ft 44ft and 66ft and a  hoist made of rope.

I hoist one of the three up and hold it taught.

I have pairs of elevated radials that slope down from the feed point.

2 per band 75m to 10m.

The feed point is just outside the shack window.

The auto tuner is just Inside the shack window.

A wander lead is used to ground the vertical wire to a ground rod.for safety during thunderstorm potential.

I can hoist up down and change vertical wire about 2 minutes.

The radials are isolated from ground and uses insulated anchors driven into earth.

I built this for a summer cottage in TN and loved it.

Three verticals and quickchange.
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