40 foot antenna, what is it for?

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Ref-Jazzy

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So I was up in my attic over the weekend looking at what i could do about mounting some soon to be made antennas. I found a triangle shaped ceramic plate that had four cooper lines coming over of it. The triangle was positioned with one point down, the two lines at the top corners ran out about 20 feet and were terminated on a cylindrical insulator attached to the rafters. The other two started an inche or so below the first town and went out and down at an angle between 5 and 6 foot and were then wrapped around nails that were nailed into the rafters. There was a twin lead no insulated wire attached to the bottom lines that ran down into a fluff of insulation. its end is unknown. Does any one have any idea as to what the hell this is.

Also there is a super old tv antenna and in one corner section i found what looks kinda like a yagi thats about 10 feet wide and about 5 foot tall with several elements and a couple of loops on it.

any help would be awesome.

Thanks
 

zz0468

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Your description is rather vague, and somewhat poorly worded, so it's difficult to understand exactly what it is. "Cooper lines"? I'm assuming you mean "copper lines". Anyway, I'm envisioning some sort of dipole fed with ladder line, and then twin lead.

Could be an old stealth ham antenna, or for SWL use.

Take some pictures and post them. Sounds like an interesting find.
 

Ref-Jazzy

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Im sorry, about the typos and not being clear. Yes, i do mean copper lines. My dogs name is Cooper, thats probably why I typed it like that.

here is a crappy cell phone pic of the ceramic triangle.



The top lines go out 20 ish feet, and the bottom lines go out 5 or 6.

The wire that comes down off of it the "twin lead" wire is a wire that looks like this

http://www.ycars.org/EFRA/Module C/twin lead.gif
 

zz0468

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It would be interesting to know the exact lengths. But it might have been a dual band fan dipole. A 20 meter dipole would be about 17 feet on each leg, a 10 meter dipole would be a a bit less than 9 feet per leg, and a 6 meter dipole would be just about 5 feet per leg.

My best guess is still some old "stealth" ham or SWL antennas.
 

mancow

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Looks like someone left a fan dipole up there to me. Hook it up to an HF rig and see what plays.
 

Rt169Radio

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It looks like a dipole antenna,maybe a homemade center or offcenter fed one?
 

Ref-Jazzy

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Ok, Went up last night with the camera and a measuring tape.

http://i.imgur.com/A1lmO.jpg

The top elements are closer to 30 feet out. It was hard to tell for sure, i had a 12 foot tape measure in one hand a flash light in the other and a full frame dslr camera around my neck. .... so the top was about 30 foot and the bottom tow that go off at an angle for about 10 feet.

Also there is this antique creature of there as well.

http://i.imgur.com/8tzF2.jpg

also this beast hiding in the corner bottom element is about 10 feet across, middle is about 6 1/2 and top is 2 or 2 1/2

http://i.imgur.com/IIwt1.jpg
 

Ref-Jazzy

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I assumed as much about the two others. its the top one that has me scratching my head. What are the chances of converting the VHF TV antenna into something for the 2m band?
 

SCPD

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Former ham

I think you may be living where a ham used to.

I think the first pictures are an antenna for 20 meters and 10 meters. From the dimensions you gave, could the lengths actually be 33' and 8' for each leg? If so, that is what you have, a homebrew dual band dipole.

The next picture looks like a TV antenna, it looks to have 300 ohm flat lead going to it. But I'm still kinda wondering if the middle one is one of those Iso-pole monoband compact ham antennas. I may have the name wrong, but most may know what I'm talking about.

And I think the last may be a 2 meter beam, although the front element looks so short. I'm shying away from the last being a TV antenna, not enough elements. I wonder if that could possibly be a FM broadcast band recieve antenna, like the ones restaurants put up ****eyed to get the piped in music?
What's got me scratching my head a little is how short the front element is.

Whatever they are, someone was unable or unwilling to get up on the roof.
 
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nd5y

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I think you may be living where a ham used to.

I think the first pictures are a homemade dipole, maybe 20 and 10, from the dimensions you gave. I'm trying to remember, what ham band is 33' a quarter wave?.

The next picture looks like a TV antenna, it looks to have 300 ohm flat lead going to it. But I'm still kinda wondering if the middle one is one of those Iso-pole monoband compact ham antennas. I may have the name wrong, but most may know what I'm talking about.

And I think the last may be a 2 meter beam. I'm shying away from the last being a TV antenna, not enough elements.

Whatever they are, someone was unable or unwilling to get up on the roof.
The middle one is a classic 2-bay bow tie UHF TV antenna.
It doesn't even look anything like an Isotron HF antenenna

The bottom one is part of an old VHF TV antenna with a folded dipole driven element and a reflector. It is way to big to be a 2 meter antenna. It looks like it has an upper VHF folded dipole on the end. They may have removed some elements so it would fit in the attic.
 

SCPD

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The bottom one is part of an old VHF TV antenna with a folded dipole driven element and a reflector. It is way to big to be a 2 meter antenna. It looks like it has an upper VHF folded dipole on the end. They may have removed some elements so it would fit in the attic.
i think whatever that antenna is for, we are looking at the way it was manufactured.
I'm thinking that antenna hasn't been modified. I don't see any holes or spots on the boom where missing elements would of been mounted.
Even if the missing elements were clamped on, the boom is aluminum, there would be shiny spots.
Don't seem like it's been shortened to "fit", the way the ends are.
And if it was a TV antenna, there should be holes we can see to mount it horizontal to a mast.
If it does have mounting holes in it, then it's mounted vertical, since we can't see the holes.

Interesting antenna.
Looks like it's got 300 ohm twinlead going to it. And I think the twinlead is going to the front element, not the middle.
If the studs are 16" apart, I'm figuring the resonant freq of the longest element is around 117 mhz, 10 mhz above the top of the FM broadcast band.
Given that a reflector element is usually about 5% more than the driven (resonant) element, I'm starting to wonder if this could very well be one of those antennas used to pipe in elevator music into restaurants and what not. I'm going to take a long hard look at the antenna on top of the Wendy's by my house, I know they have one of these at a 45 degree angle mounted on the roof.
I'm going to dig thru my junk boxes, it seems I used to have an old antenna book that talked about making a wideband beam with little gain that would look like this.

(And I think I have put more thought into this then what is really needed. Sorry, the wife's babysitting and I'm "hiding' in the shack with lots of time on my hands),
 
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LtDoc

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That wire antenna appears to have the long/short elements cross connected, making it a 'dual' OCF antenna. being so close together, I have no idea how it might work. Of the three antennas, it may be the easiest to convert for other use. How well it may work is a different thing altogether...
- 'Doc
 

Ref-Jazzy

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The wire antenna, I may fudge with to make it a 2m antenna. I have some friends that are getting into ham radio. We even built a quad helix antenna the other day to record the signal from a noaa sat.

So we may modify the wire antenna for 2m and the yagi may be taken apart and used for parts on other antennas.
 

kb2vxa

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That one is easy, a two band fan dipole for shortwave, the lengths are wrong for any ham bands. Old is right, I haven't seen a center insulator like that in a gazillion years.
 
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