I've been using an open-wire fed rotary dipole that is a halfwave on 20
meters on all bands from 40 through 10 meters for the past 4 years or
so. The feeding/matching system has gone through various iterations, but
now uses homemade open-wire line of no. 12 wire (2 mm) spaced 4.5 inches
(11.4 cm), a very slightly modified Johnson kW Matchbox, and a pair of
inductors for reactance cancellation on 30 meters. The line is about 34
feet long (10.4 m). The SWR on the worst band (7 MHz) approaches 100:1,
but losses calculated by TLW are around 1 dB or less.
73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/
On 7 Jan 2019 00:15, K9MA wrote:
The really attractive thing about open line, and even window line, is
that its loss is so low you can use it at a very high SWR, and take care
of the matching at the station end. This is especially useful for
multi-band antennas. The famous G5RV, for example, will work just
exactly the same fed with window line and a tuner as it will with the
usual matching section.
73,
Scott K9MA
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
