Very interesting Eric! Of course, along that line of hydrogen safety, the Hindenburg was a HELIUM dirigible. Although the Germans had an excellent safety record with hydrogen, they understood the danger vs. small extra lift from using that gas and the Zeppelin company designed the Hindenburg to use the safer helium gas.
Unfortunately, the Nazi party had taken control of the German government by the time the helium was needed and the USA - who had the only supply available - decided not to allow the export of the helium gas to Nazi Germany. So the Hindenburg flew with hydrogen in her lift cells. After all, the Graf Zeppelin had flown over a million miles safely with hydrogen. The Hindenburg herself hundreds of thousand miles with hydrogen in her lift cells before, on her second long voyage of 1937, regrettably flew into history. Makes one wonder what aviation history had been like if she were carrying helium as originally planned... Ron AC7AC -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of EricJ Sent: Monday, March 27, 2006 5:48 PM To: [EMAIL PROTECTED]; elecraft@mailman.qth.net Subject: RE: [Elecraft] RE: ridge vent as antenna? I have a commercial balloon rating (gas and hot air) so it was inevitable that I would try a balloon antenna. As someone on here mentioned, it is not a practical solution if there is any appreciable wind or there are any hazards such as power lines. However, I have used them to raise a thin 160 meter vertical in the evening when propagation came up and the winds died down. I didn't have much of a radial system and nothing to compare it to, but it worked fine all night long. Helium lifts about 1 ounce (28 grams) per cubic foot so you need to keep the weight of the antenna down. And you don't just want to lift the wire. You want enough additional lift to put a little tension on it. Don't forget the weight of the balloon as well. Obviously you have to lift that as well. I would think if a guy lived in Amarillo and knew Jack B. Kelly he could put up a rotating balloon beam on 160. The alternative would be hydrogen, but it's very tricky to handle and only has about 5% more lifting power. In Europe they race gas balloons with hydrogen, but have to coat the inside with graphite so they don't let the smoke out. In the U.S. we always used helium. You could always tell a European team here in the U.S. because they were covered in sooty-looking graphite. I wouldn't mess with it unless your liability and life insurance are sufficient. Eric KE6US www.ke6us.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, March 27, 2006 3:30 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] RE: ridge vent as antenna? In a message dated 3/27/06 5:31:57 PM Eastern Standard Time, [EMAIL PROTECTED] writes: > The problem with balloon lofted antennas is you cannot often have the > balloons only go straight up. A special type of aerodynamic balloon, called a kitoon, was developed to deal with the problem. Bacically it was a blimp with inflated wings. In still air it was a balloon, but when the wind blew it would turn itself into the windd (reducing drag) and the wings would provide some lift, helping to reduce the lean-over effect. WW2 military thing, IIRC. They used hydrogen instead of helium, Made the hydrogen in a chemical process involving water and a dry chemical. I still prefer a tree and slingshot, or a mast. 73 de Jim, N2EY _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
