Herb Schoenbohm wrote
> If you can get hydrogen it is much cheaper with nearly twice as much
> lifting power ...
This is a common misconception, based on the assumption that the lifting
power is proportional to the molecular weight (or density) of the
filling gas. The lifting power is actually proportional to the
difference between the effective 'molecular weight' of air,
(approximately 29) and the molecular weight of the filling gas. The
ratio of the lifting power of hydrogen to helium is thus
(29-2)/(29-4) or 1.08, and not 2.0. You would have to weigh the lower
cost vs. the greater risk to decide if an additional 8 percent lifting
power is worth using hydrogen.
Bert, VE3QAA
--
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com
|