Re: Superpressure balloon valve / was Re: [GPSL] K5NOT-11 WSPR Balloon Failure
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I am curious. Many of us have measured the atmospheric pressure versus altitude. I have wanted to, but haven't, measured the pressure inside the latex balloon as it rises. Has anyone measured the pressure differential (inside vs outside) of the latex balloon as a function of altitude? How much difference are we talking about trying to control with this valve. If the balloon were a fixed volume you could do the calculation, but the latex balloons are not.
Dennis Klipa, N8ERF
On Tue, Jul 21, 2020, 8:23 PM Joe WB9SBD <nss@...
It was a 1500 Kaymont balloon.
Knowing the pressure differential is extremely low. When I
tested the ping pong ball, I know it leaked badly. The texture
of the ball just would not give a good seal.
I went with the silicone on both the "O" ring and the ball.
I also went with a pressure of the spring, Actually a spring I
just could not find a spring suitable. So I used a left over
strip of balloon latex, attached to the ball and to a acrylic
The shaft was rotated to tighten the tension on the ball and
I made it as loose as possible,, just enough to make the seal,
and I mean barely!
I was worried that motion would even break the seal. It was that
Even as light as that was, it was not light enough, the flight
still had a standard flight profile with rise to burst altitude,
and did still pop.
On 7/21/2020 3:41 PM, Hank Riley via
please tell us more.
or other envelope? How did it work out for you? Any
special reason for trying this valve method out? What
altitude was reached? How long did it remain in the air?
On Sunday, July
19, 2020, 09:06:33 AM EDT, Joe wrote:
I did that
once. But the ping pong ball surface is too
textured and does not make a bubble tight
seal. I did a silicone ball and o ring.
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