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LF: Balloon flying

To: "rsgb_lf_group" <[email protected]>
Subject: LF: Balloon flying
From: "Alan Melia" <[email protected]>
Date: Tue, 14 Mar 2000 23:58:48 -0000
Reply-to: [email protected]
Sender: <[email protected]>
Hi All, as a result of the donation of some old mags I came across the
following table in an article in 73 mag (April 1972 ), which may be of
interest to those without a tower contemplating a BIG vertical. The table
relates to lift generated by a helium filled balloon at different gas

Balloon        Gas vol         lift (lb)         lift (lb)
diam. ft          cu.ft.         @0degC       @20degC
2                   4                0.25               0.25
3                  14               1                    0.75
4                  33               2                    2
5                  65               4                    4
6                 113              7                    7
7                 180             12                  11
8                 268             18                  17
9                 381             26                  24
10               523             36                  33
11               696             48                  44
12               904             62                  58
Sorry to our metric friends (1ft=0.3m and 1lb=0.45kgm or there abouts) I
think metres are unknown the other side of the pond. They even measure the
size of the engine bay in cubic inches (It IS the engine bay isn't it?)

It goes on up to 16 feet diameter but I reckon if you have got a big enough
garden to blow up a 16 foot diameter ballon you have enough room for tower!
He mentions flying a 160foot vertical with an 8foot weather balloon inflated
to 3.5 feet diameter. (He ran out of gas). He also relates burning out a
30AWG aerial wire with about 180 watts on 80m. Though I must admit I have no
idea how he derives an impedance of feed 50ohms for the end of a halfwave!
That shouldn't bother us as, at least I, will be quite happy with a quarter
wave on 136!

Cheers de Alan G3NYK
[email protected]

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