Look into the sources of advertizing balloons. I bought one shaped as a
dirigible about 25 years ago to
lift my vertical. It was moderately successful for the HS72B operation, but it
was quite a lot of
commotion and trouble and cost. I do not recall the size of wire I used, but
it was not small # 18, but
then, the dirigible was a net size of about 4 or 5 feet.
Long before that effort (nearly 60 years ago, now that I think on it) , I
tried a weather balloon, and I
made my own hydrogen ( out in the desert with no-one else around and nothing to
burn)- it was a rather
complete failure for reasons evident in the after analysis - the mix of Sodium
Hydroxide and aluminum
chips made hydrogen just fine.. but it was not filtered and the Sodium
Hydroxide rode some of the chip
pieces up into the balloon and ate holes in it. Predictable, but then, I was
using late teen grade
enthusiasm to drive the decisions.
ALL - ALL! Balloon-Dirigible lift systems are GROSSLY impacted by wind -
anything over 3 or 4 kts
makes the vertical very much not vertical. stabilizing anchor ropes add weight
and any tension is
translated into effective weight.
Aluminum pipe/rod and steel may sound more expensive, but the bottom line is
that it works and is
reasonably predictable.
Balloons within our general price capability are pretty nearly universally
unsatisfactory. and your
insurance carrier will NOT be pleased when the balloon breaks the wire at the
bottom and drags it across
a half dozen power lines. Even if they are miles away, that trailing wire will
get there rapidly under
the influence of as little as a 10 Kt wind.......
The Titanex verticals DO work (anybody still have one of the 96 footers still
whole?)- careful use of
flex tolerant tubing and guy points will make a quite effective vertical in a
relatively small ground
area.
even better, build a small but climbable cross section tower (even guyed with
ropes if temporary) for
about 60-70 ft and stick aluminum tubing out the top
(I speak with considerable experience - that's the antenna approach we used at
XZ0A, thanks to N5IA (SK)
and G3NOM (SK)....
Robin, WA6CDR
XZ1N
XZ0A
HS72B
VP6DX (where we used a Titanex)
----- Original Message -----
From: "Mark - N5OT" <r-emails@n5ot.com>
To: "TopBand List" <topband@contesting.com>
Sent: Monday, November 08, 2021 13:17
Subject: Re: Topband: Balloon Supported Vertical
Been There Done That
You might want to figure the weight of what you have to lift. One would think
it was, like, duh, you
make a wire vertical and fill a balloon full of helium and ... but it turns out
you need to be careful
about the weight of the wire and insulators and you need to project how much
helium you can use and how
much lift you will need and ... all that.
Just saying all that because the last thing you want to find out is, after
you've got it all together,
you just can't get it up in the air.
I seem to recall I needed more like a 3 or 4 foot balloon to lift mine.
And be careful of the sticker shock on the gas. I thought it was a lot of money
20 years ago. Rumor has
it, it has not gone down in price.
The first one worked well until I had a bad wind.
The second one had some kind of corona arc off the top of the wire which popped
the (relatively
expensive) balloon after only a couple minutes of testing it out. Or something.
It popped on a clear
calm day but under Full Power.
Anyway, that wrecked my day. I decided it wasn't fun any more and have been
using more conventional 160
meter verticals since.
I think we wrote it up in the NCJ but don't remember and have slept since then.
Oh sorry, you asked where to get the balloons. I think I got mine from a party
supply store. It was not
mylar.
Note - Googling reminds me of these facts:
Helium can lift 1 gram per litre.
A balloon 2 feet in diameter will contain 118 litres of helium.
That will lift 118 grams of antenna, = 4.1 ounces.
132 feet of bare #18 solid copper wire weighs 10.4 ounces.
A 2 foot balloon filled with helium will not lift a 160 vertical made of #18
wire, not to mention any
extra line or insulators, etc.
But a 4 foot balloon will lift a little over 2 pounds.
Now I'm having nightmares again.
73 - Mark N5OT
On 11/8/2021 2:48 PM, Dick Bingham wrote:
Greetings All
I want to try a balloon supported Vertical for 160.
Any advice on sources for balloons? Mylar material
and diameters up to 2-feet would be my choice.
73. Dick/w7wkr at CN97uj
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