TopBand: Balloon Vert ...Need Help.

[Keith Jillings]

utahfolk@konnections.com wrote:
 
> We are planning on trying out a 1/4 wave vert on 160M this year.
> Altitude is 6000 feet.  What kind of wire do we use (KW power)
> and how do you tie the balloon to the wire/line ...

It's a LONG time since our group did it, and we weren't running that
much power.   From hazy memory, therefore:

1.  We did it with a half wave of wire.   The biggest problem was wind
moving the wire so far away from the vertical (and back again) that it
was very hard to keep "on tune".   We ended up "guying" it with a very
long length of fishing line to keep it roughly over the base.   When the
wind blew, it then went up and down - draping wire over the ground...

2.  The balloon isn't strong enough to fix the antenna directly to it
(well, ours wasn't).   We used a "strawberry net" with the balloon
inside it, and the wire fixed to a length of rope off the net.  The
balloon was completely inside the net.   That worked well.

3.  Our balloon was about 8 feet in diameter.   It was quite able to
support 270 feet of fairly light wire.   But the whole array was a devil
to handle when the balloon was full.

4.  We used hydrogen (very much cheaper than helium, and not a great
risk in the wide outdoors).   The balloon didn't seem to generate much
lift until it was almost full and beginning to stretch.

5.  By the time we'd overcome all the above, it was too late for that
session.   The experiment was repeated a few weeks later, when the wind
was lighter.   The balloon had been up for a few minutes when a local
farmer, thinking it was a flying saucer, shot it down.

Not tried since.

G3OQT was involved in the same experiment - he's younger than me so his
memory may be able to add to the above.

Keith
-- 
Keith Jillings
G3OIT  GW3OIT
G-UTSY  Arrow III   EGMC
amen@earthling.net
ICQ 10590057


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