The 40m double extended Zepp is about 180' feet long. I had one 326'
long (#10 copperweld) up for 80 meters until I ran out of supports. I
used it from VLF through 144 MHz with different tuners. My feed line was
not a handy length for tuning with the Johnson match box on 80, so I
used a set of home made tuners. It series tuned on the low frequencies,
but parallel tuned on 15m and shorter wavelengths. I worked all over the
US on 6m and out to about 350 miles on 2m CW. (Ames, Iowa to Benton
Harbor Michigan). I work the same range on 2m with a fair beam these
days.
A double extended zepp with a feed line other than 1/8, 3/8, or any 1/8
+ n/4 length feed line will reflect a very reactive feed impedance. The
resistive component will depend on the feed line impedance, but if the
feed line is 1/8 + n/4 (where n is any integer including 0) it should be
tunable with the Viking Match boxes.
73, Jerry, K0CQ
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