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Author Topic: Vacuum tube HF QRP from a parachute at 13,000 ft, Oct 12 2013  (Read 2443 times)
SWL377
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« on: October 25, 2013, 02:33:19 PM »

https://sites.google.com/site/bc611ww2radioparachutejump/
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WX7G
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« Reply #1 on: October 25, 2013, 10:42:51 PM »

They didn't make a QSO though. The BC-611 transceiver 360 mW to a wire a "only a few feet long" on 75 meters doesn't make for a strong signal.

A matching network between the BC-611 with a longer wire carefully threaded along the parachute shrouds could improve the signal.
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BG6EXK
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« Reply #2 on: October 27, 2013, 02:04:10 AM »

great height . contact me with gmail bg6exk@gmail.com   73   de BG6EXK
« Last Edit: October 27, 2013, 02:12:43 AM by BG6EXK » Logged
SWL377
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« Reply #3 on: October 30, 2013, 10:20:48 AM »

They didn't make a QSO though. The BC-611 transceiver 360 mW to a wire a "only a few feet long" on 75 meters doesn't make for a strong signal.

A matching network between the BC-611 with a longer wire carefully threaded along the parachute shrouds could improve the signal.

A longer antenna will probably be the only effective solution. It's too dangerous to mix antenna wires and suspension lines so we will use a trailing wire antenna stowed in a pouch and deployed after opening. Our team has flown a jettisonable trailing wire HF antenna before and it deployed fine. It was a PAR end fed dipole cut for 20M. We flew a PSK31 beacon. If you land off DZ you might have to pass over power lines on landing approach. You sure don't want to drag a wire across those. Thats why we jettison our traling were antennas at about 1000 ft over a clear area. We used an acoustic beeper and an orange flag on the end to help our ground team locate it in tall grass and it worked, none lost so far.

You dont have to be an experienced solo jumper to do parachute mobile QSOs. It can be done on tandem jumps if you get it cleared with your jumpmaster and DZ safety officer. Check this out:

http://parachutemobile.wordpress.com/2011/03/

73,
Mark
AF6IM
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