eHam

eHam Forums => Elmers => Topic started by: VE6AGE on September 24, 2006, 07:32:47 PM



Title: Wire Antenna / Hilium Balloon
Post by: VE6AGE on September 24, 2006, 07:32:47 PM
Has anyone ever tried tying a long wire antenna to an hilium balloon and what was the results.
Just curious.
I was thinking of trying that out if I could ever find a balloon that's big enough to lift the wire.
Any ideas or suggestions??
Denis
VE6AGE


Title: Wire Antenna / Hilium Balloon
Post by: K3JVB on September 24, 2006, 07:39:06 PM
Do a google search for weather ballons.
I recall seing one sold from England...
300 feet of line, and away you go on 160 !
Watch out for low flying planes !
73
JohnB


Title: Wire Antenna / Hilium Balloon
Post by: W5GNB on September 24, 2006, 07:59:49 PM
I did this with an 8-foot weather baloon once and supported a 300-foot wire.  it worked GREAT!!

I got my ballons from Edmond Scientific company and the helium from the local welding shop.

The wire I used was about #20 magnet wire, anything heavier might be a little too much since the baloon does not have a lot of lift.

Watch for powerlines!!

Be sure you are away from anything that may fly into it, you are usually safe below 300 feet.

I used a tuner and a large groundplane on the ground and set it up for 160 meters.  

Have fun!!

73's
Gary - W5GNB


Title: Wire Antenna / Hilium Balloon
Post by: K3AN on September 25, 2006, 06:07:45 AM
Remember that once a vertical antenna exceeds 5/8 wavelength long, adding more length means more of its energy is radiated upwards at uselessly high angles. A 75 foot vertical wire will work great on 80 and 40 meters, but will get progressively poorer as you go further up in frequency. To optimize performance, you'll want to scale the wire length to the desired band.


Title: Wire Antenna / Hilium Balloon
Post by: WW5AA on September 25, 2006, 07:20:49 AM
If you go over 199 feet it must be lighted and if you are within 5 miles of an airport you better contact the FAA for guidence. I hate surprises when I'm airmobile.

73, de Lindy


Title: Wire Antenna / Hilium Balloon
Post by: WW5AA on September 25, 2006, 07:26:17 AM
OOOooppps,

I guess it would be who regulates aircraft ops in Canada...

73, de Lindy


Title: Wire Antenna / Hilium Balloon
Post by: KC8VWM on September 25, 2006, 08:17:12 AM
In Canada, the authority in charge of overseeing all aeronautical activities is called "Nav Canada"


Title: Wire Antenna / Hilium Balloon
Post by: WB2WIK on September 25, 2006, 09:57:54 AM
I've used Helium balloons to raise wire antennas (and use them that way) many times.

A single 6' or 8' balloon isn't a great way to do it, because the balloon has so much surface area it catches wind very easily and the slightest gust will bring the wire down close to horizontal.

The latex balloons from Edmund Scientific et al are pretty much single-use balloons.  Good for a Field Day or similar short term operation, they last maybe 2-3 days if the weather's fairly calm but do not expect them to last much longer than this.  For one thing, Helium is a very small molecule and leaks out of almost anything...

I found a better approach to lifting a wire as an antenna is to use several smaller balloons tied along the length of the wire, maybe every 10' or 20'.  Use one at the "top," then another one 10' down, and then another one 10' below that, etc.  That will hold the wire much more vertically than using a single larger balloon at the top.

Try to avoid sucking all the Helium into your lungs to make squeaky voices.  That really is fun, but Helium's expensive and before you know it, it's all gone and there's none for the balloons...

We used balloon-lifted 1/4-wave vertical antennas for 160m, installed over a large radial field of wires on the ground, to do very well in a couple of 160m contests back in the early 80's.  Much faster, easier and cheaper than installing a 125' tower to do the job.

WB2WIK/6


Title: Wire Antenna / Hilium Balloon
Post by: WA1RNE on September 25, 2006, 10:37:16 AM
RE: Wire Antenna / Helium Balloon      
by WB2WIK on September 25, 2006    

I've used Helium balloons to raise wire antennas (and use them that way) many times.

A single 6' or 8' balloon isn't a great way to do it, because the balloon has so much surface area it catches wind very easily and the slightest gust will bring the wire down close to horizontal.


 
 >>> For winds around 20 MPH or below, the way we got around this was to add 3 tether lines at the balloon-antenna junction, using 30 lb. test fishing line spaced at 120 degrees. it's been 20 years, but as I recall, our 80 meter 1/2 wave vertical was made from # 18 stranded insulated wire supported by (2)  6 foot Edmund weather balloons.

 It definitely gets a little dicey with *sustained* winds of  20 MPH or more.

 This was a Field Day site antenna at 255' above sea level and was fed with a homebrew tuner and decoupled with 3 elevated radials. It worked awesome......



 Chris


Title: Wire Antenna / Hilium Balloon
Post by: KB4QAA on September 25, 2006, 12:19:54 PM
You definitely need to be using larger balloons like weather balloons.

A couple field days ago, we tried it with scads of party balloons, and it just wasn't possible to get enough lift, and a breeze came up that layed the wire out sideways.

Do use the very lightest wire you can.  Remember the size of wire below 28AWG won't affect your efficiency.

bill


Title: Wire Antenna / Hilium Balloon
Post by: WB2WIK on September 25, 2006, 02:16:26 PM
We did this successfully and gave a rather "large" demo at the contest forum at the Dayton Hamvention in 1983 (presentation by KT2B & WB2WIK).

The "tether" lines, we found, don't really help much because they just add their own weight and wind drag, and cannot counter the effect of wind blowing sideways on a tethered balloon simply drives the balloon downwards, to the ground.  If, on the way down, it happens to touch tree braches and stuff, it's likely the balloon will break.

We didn't use very lightweight wire, we used #12 stranded, insulated wire.  But we had vertical lift force of about 60 lbs.  It was enough to pick up a child and take him airborne, so be careful not to hand the line to any small children unless you're planning to send them off to the land of Oz.

The ultimate solution was to use a succession of balloons along the length of the antenna wire; works better than a single large balloon at the top, for the reasons previously stated.  That, and it simply "works."

You'll note the big helium balloon "strings" at car dealers and such announcing sales and trying to draw attention of motorists from far away always do this: Have a lot of balloons up and down a long string.  They stay much more vertical than any sized single balloon possibly could.

Better still is a kitoon.  A kitoon is 1/2-kite and 1/2-balloon; what it really is is a helium-filled balloon that acts like a kite because it has fins that help lift it with the slightest puff of wind.  So, instead of wind dragging it down towards earth, wind will tend to try to lift it higher still.  That's a great solution, except for the cost.  I arranged to buy one, just to find out.  I bought it from a large sign and balloon shop in town who sells them mostly to car dealers and commercial parades and such, and a 5' kitoon having about 100 lbs of lift cost $220, not including the helium.

But it was a good experiment, and yep, the darned things work as advertised.  It's not latex, and is metallized, so it is reusable.

WB2WIK/6


Title: Wire Antenna / Hilium Balloon
Post by: DONDON168 on September 25, 2006, 06:58:15 PM
I read up on this out of curiosity awhile back. I found alot of info on using kites, the biggest problem that I read about was static electricity but I don't know if it is a real problem or just something to worry about. I also found alot of info on people using cameras on kites. I would like to try the kite antenna one day. I read about one that stayed up for several days just tied to a stake. I looked but did not find where I saved those sites. Just do a search for kite antenna and you should find some sites.


Don,KI4RHG,73


Title: Wire Antenna / Hilium Balloon
Post by: K4SAV on September 25, 2006, 09:15:08 PM
I have seen recommendations for using a flat disk below the balloon.  Then when the balloon gets blown out of vertical, the disk converts some of the horizontal force into lift.  I haven't tried it, so I don't know what the complications are, or how well it works.

Jerry, K4SAV