The AM Forum

Is this a crazy thought or what????
What kind of a hassle would it be to launch a balloon 240 feet OR (one wavelength) in the air with a wire attached for 160M? Is it true that a wire or tower a full wave length long would not need a ground radial system?
Fred

A Google search turned up 1.14M hits for a balloon antenna.

A big balloon, helium, wire, and probably lots of prayers. Short duration type activity; wind, birds, tall people, balloon venting, etc. probably need to be taken into consideration.

Not to mention airplanes, electrical wires, static discharge.  :D  Imagine if your wire broke at the bottom and the baloon got away, what kind of havoc it would wreak upon the nearest municipal power grid it encountered!

Fred,

Even though the 1/2 wave vertical is of higher input feed impedance thus can tolerate a higher ground resistance number,  it still needs a radial system to return the ground current to the base.

In addition, a 1/2 wave vertical has a lower take-off angle than a 1/4 wave vertical. The 1/4 wave is low as it is. The problem here is you need a bigger cleared perimeter area than normal around the vertical to permit this low angle energy to radiate. With take off angles down around 10 degrees on 160M, you better have no houses, hills, power lines, etc for at least a 1/4 mile around, minimum, or the advantage of the lower angles is simply wasted in attenuation.

I'm afraid there's no free lunches, even wid a balloon...  ;D

73,
T

If I were to do it, I'd try a 0.75 wavelength wire. This gives a nice medium angle take off pattern - better for stateside AM use.

The radio club I am in tried a balloon one field day for a 160 antenna. The problem was that the wind "pushes" the balloon. The more the "push", the lower the balloon would be and the more toward horizontal the antenna would be. Didn't work out well with the weather they had that year. However, very calm conditions would be much better.

I " blimp" shaped baloon will keep its nose into the wind and will stay close to its design altitude. You also might rig up a deadman type valve on the baloon to dump its gas if it gets away from the antenna part. A lanyard is connected to the antenna and a "plug" so if there is a seperation , the lanyard  pulls the plug on the balloon.  You want to design the antenna to be weak at the baloon so it will break here not anywhere else...  Or, some RC modelist creates a Red Barron Death Plane to chase said runaway baloon and do a Kamakaze.......  klc

That would be SO freakin' awesome! With one of those little ATV transmitters, so it would be like the "smartbomb" targeting video... Someone's gotta do this!  ;D

^^ If you try this, make sure you fill the balloon with hydrogen instead of helium.

Yes, the results are spectacular!

(http://www.corrosion-doctors.org/Hydrogen/images/hindenburg-1937.jpg)

Bruce,
My Dad was a kid when he saw that ship go over Hartford on its way to doom in N.J.

Put a little oxygen in the mix with that hydrogen so that sucker vaporizes up in the air with one helluva report. :o

Otherwise, with my luck, it would come down slowly in a huge blaze and land on the roof of some yuppie McMansion and torch the joint.

...oh the humanity....

When I lived in the Philippines they used hydrogen for party balloons rather than helium.  A colleague was burned pretty good when he was in some bar smoking next to a bunch of balloons and they exploded.

The Phillippines, say, isn't that the home of "Love You Long Time"!

(http://www.b3tards.com/uploads/me-love-you-long-time.jpg)

A Marine I know called it the home of LBFM....and gleep if I spelled it correctly

If the wind is still the balloon will work just fine. If it gets windy use a kite. I made a box kite about the size of a large refrigerator out of wooden dowels and rip stop tent nylon. It was a thing of beauty. It would haul up a very long antenna on a day with a good wind. I used a long chain link fence at an old Nike Site as a counterpoise & it worked well with a homebrew antenna tuner. I did see a 6 foot helium balloon with a down-pointing video camera at a hamfest a couple of years ago in Vernon, Ct. You could see what you look like from above on the TV monitor.
I don't know if the 200' antenna regulation for aviation hazard lights applies to this. Check out the link.

http://www.spyflight.co.uk/Aerostat.HTM

You would definitely not want the balloon/kite to be tethered by the antenna wire.  Rather, you would want to tether the balloon/kite by some nylon cord, with a breaking strength higher than that of the antenna wire.  You then run the antenna wire vertically down from the balloon/kite to your rig.  You can move the anchor point for the nylon cord as the wind direction shifts to maintain the vertical orientation of the antenna wire.  Or you could 'guy' your balloon/kite with two or more cords, and the position of the kite will end up pretty stable.  The advantages of this are:
1.  If your antenna wire breaks, the balloon/kite is not lost.  No wire coming down miles away across power lines!
2.  Because the stress of holding down the balloon/kite is now held by the cord, the antenna wire can be a thinner gauge, saving the weight of the additional cord.  Consequently, a smaller balloon/kite would be needed.

Dave

You got a box kite to fly?  Congratulations...my Hi-Fliers always self destructed before I could get them stabilized.  But...I made miniture box kites out of soda straws & tissue paper and the flew good.

The Cornell Amateur Radio Club did this years ago for a couple of 160 meter contests. As I recall they used a 5/8 long vertical radiator on the balloon and did it down near the salt mines on cayuga lake so there wasn't much around for the wire to fall on. They talked about the balloon getting blown a bit, but mostly they were on at night when the winds were calmer. No one here has done it for years that I know of.

There was also a QST article about 5-10 years ago about hoisting antennas using a special kind of kite called a 'Scott sled'. The design in the article was based on using tyvek of the type used for wrapping houses, and some vertical pvc or dowel sections. Looked pretty simple to build. That kite was developed for I think the weather service when they used to fly their instruments on kites instead of releasing free balloon radiosondes. They are supposed to fly in quite mild winds, and at very high angles.

here's a couple of websites I found about sled kites.

http://www.kites.org/zoo/single/sled/sled.html

http://members.cox.net/gengvall/k_sled.html   in this one you can see the high angle to the cord

Some pages on kite lifted antennas

http://www.njqrp.org/mbrproj/kite/kites.html

http://www.wireservices.com/n9zrt/live-wire/events/marconi/kitefaq.html

http://www.chem.hawaii.edu/uham/kite.html

Frank said:
A fellow shipmate married one and refer to her as an LBFM. My apologies to the MOPman, just stating facts.

I find them very nice people myself.

Frank said
...And damn fine cooks! Can you say lumpia?

I'm married to one as well.

A big enough balloon could lift the center of an inverted-V.  I think that would be better than a vertical out to 300 miles.  The antenna would hold the balloon in one dimension, and some side ropes could hold the balloon in the other dimension.  Or maybe an inverted-V turnstile, and the whole thing would be antenna.  Could be cool.

Good idea about using ropes, and thinner antenna wire for lower weight.  #16 wire should be fine, maybe even #18.

Yes, agreed! No radials needed and a great local-medium range pattern, especially if it was flown at 250', 1/2 wavelength high.  Maybe a lightweight, thin  aluminum type CATV coax would be good too.  I have some here that is about 1/3 the weight of the copper stuff.

BTW, back in 1966, being kinda of a nutcase when it came to antenna ideas, I bought that 8' weather balloon you used to see in the comic book ads. It was about $10 or so. Paper route money.

I planned on filling it with helium and floating up a dipole in the backyard. It was advertised as neopreme? or whatever that was to me back then. I figgered it was strapping like rubber. Anyway, I filled it up in the cellar with a reverse vacuum cleaner. I slowly increased its size over a series of days as the info suggested. At about the third day it was about 6'. While I was blowing it bigger I guess something on the floor stuck it and it blew up in my face. I was covered with this white powder.. probably coke... that was used to keep it dry inside. I looked like a three stooge in a bakery explosion.

I guess it was lucky I didn't spend more money on helium. It never would have pulled up my dipole anyway.

Later I went to Hatrys ham store and bought 170' of Channel Master telescoping mast. 170' was the FCC limit in 1966, so I wanted to be legal, of course. I actually tried to put it up in the back yard of a suburban house. That's another terribly wasteful story for another time... sigh.

73,
T

Hi:

Our radio club tried this in the 1980's. It was inefficient, had lotsa static electricity when it was being reaised and the FAA was looking for us.

On another note in my younger days a group of us in another club flew trash bags filled with Oxygen and acetyline with a fuse for jJuly 4th.

The cops were looking for us too after the very large "BANG".

Neither group found us.....

73
Dan
W1DAN

"flew trash bags filled with Oxygen and acetyline with a fuse for jJuly 4th" ....  do the words  new hartford enter into this equation??   If so, I know the launch site......    klc

Field Day 1975 - my first.  The radio club I joined decided a helium balloon and wire vertical would be a good thing to try.  We were located in a decent spot and up went the wire.  I understand it worked fairly well but I don't remember exactly how high the balloon was.   I know it built up a lot of static; doofus (me - age 13) grabbed hold of that wire.  Surprise!

Late that evening as a thunderstorm passed nearby there was a very close clap of thunder.  Except it wasn't thunder.   After the flaming mess landed, the guy who'd been charged with getting the balloon said "ya know, they didn't have any helium so they suggested hydrogen.  I hope that wasn't a mistake."

I SO want to hear this story!

I'm running a Gotham vertical at 170 feet wx is FBOM. Rig is a pair of 4CX5000A at 72 watts. Coax is 300 feet of RG174.

RG59 to a Gotham Beam. That's what the real strappers use.

OK Guys
Dig out the hip boots and prepare for the fish stories..............hi
BS Level= 3.7

OK, you twisted my arm...

I was about 13 years old with a paper route. Not knowing anything about mechanics and the fact that Channel Master telescoping mast that thin couldn't stand more than 40' guyed every 10', I went in and paid for 17 sections. Now to get it home. I planned on carrying all 170' onto the Connecticut Bus Line that ran from Htfd to Windsor, about a 5 mile ride. Corky the ham salesman took pity on me and loaded it into his station wagon and gave me a ride home.

I only had enuff cash to buy 150' of guy wire. In reality I would have needed several thousand feet or more. The next day I started pushing the mast together in sections. I wanted to make sure it was good and tight so I slammed it against the house foundation. I split the seams of a few mast female ends. My dad came out yelling that I might punch a hole in the wall.

After a while the mast was about 100' long, snaking through the yard on the ground. I was beginning to have grave doubts if it would stand up at 170', so I decided to make two masts at 80' each to handle a flat dipole. So there's two 80' masts on the ground with only 150' of guy wire available. I went down to the hardware store and loaded up on clothes-line rope. After everything was laid out I went down the street recruiting all the neighborhood kids I could find for the mast raising. We all pulled like crazy, but the mast just swung around and kept falling to the ground like a big snake. A strapping neighbor came over and helped but that made it worst as the mast fell over and hit me pretty hard on the head.

All the kids went home and there I was with an expensive mess in the yard. Then I got the idea of chopping down a big tree in the nearby woods as a support and lashing the mast to it. I spent about three days chopping and dragging it into the yard. My dad put in some concrete and with the help of four neighbors we stood up this 40' tree pole. We got a tall ladder and lashed the mast to it and slid it up to about 60' with guy ropes - a pulley at the top to raise and lower inv vees.. Not bad, but not 170' like the original plan.

I got on the air with it using a 75M invereted Vee. I was immediately disappointed because I was getting only 5-7-9s, not 599's. I figured the mast was interfering with my inv vee. Dumb! So after all this work I then chopped down the tree and mast. My dad came home and was livid!

I then took the remaining mast and lashed three 50' sections together in one fat pole. This was a major job to erect and guy, but it was worth it. It solved the problem of having no tree supports on one side of the yard, so now I could put up a flat dipole at 50'. It worked FB for about a year.

Finally, the ultimate antenna using this masting was to take 40' and climb a 60' tree. Then I slid it up the tree and lashed it on. The top was at about 75' and guyed with the 75M inv vee itself and open wire feeders. The Tron came over in 1972 and commented that it was the highest AMer ant he had seen to date...  ;D

As the years went by I would find a pile of that old rusted masting. A friend even used some of it on his inv vee projects five years ago. I used to think if I only had all the money I spent on hair brained antenna projects from those early days...  But it was all part of the magic back then.  When I look at a picture of Hiram's bird cage at 50' using haywire guyed masts in a Hartford urban area, I understand.

73,
T  

Less catastrophic, yet more bizarre of a story than I had imagined. ;) Thanks!

-Jason kf6pqt

Now, just imagine what he would have done if he discovered that magical device called a welder.................................

"A strapping neighbor came over and helped but that made it worst as the mast fell over and hit me pretty hard on the head."



   6m   -- now we know why .... ..   klc

^^  ;D ;D