The Aug 1998 issue of CQ Magazine has an article
about balloon supported TopBand antennas "A Balloon-
Lifted Full Wave Antenna for 160 Meters" on p 38.
It describes using two balloons to support a full
wave antenna in an Inverted L configuration. Using
two balloons to support the antenna in this manner
keeps the maximum altitude under 250 feet for a full
wave on 160M. Sources for balloons and helium, antenna
design and tether line rigging, applicable FAA Regs
re. moored balloons and a tuner to match their
antenna's high impedance are presented. The authors
- K9ES and AD4ES - report a 2:1 SWR bandwidth from
1800 to 1870 kHz.
My comments: An interesting system but pretty complex
to rig and deploy on a regular basis. I use a 1/4 wave
balloon lifted antenna for 160M with a conventional radial
ground system. This antenna matches directly to 50 ohms,
deploys in minutes and works well. Received a 59 report from
Carl VP8/G4VFU with 100 watts before it blew down. :-)
The CQ article has some good tips on balloon rigging
and designing/matching long antennas for 160M.
The two balloon antenna may be of interest to contest stations and
DXpeditions for 160M. - Jon N0JK
--
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com
|