Okay now that I've relocated back to Alaska and living
on the top floor (14 th) of a high-rise apartment, I can't put up any
exterior antennas. I guess I should just limit myself to work mobile or
portable then? Not!
Hey, what ham would'nt want to take advantage
of being 150 feet above ground, hi hi! This is a continuation of my
"KL7JR Vertical Pancake Dipole 10-20 Meters" design at Hamuniverse.com.
This custom design is to fit my 4 ft by 8 ft living room window (yes
honey, the antenna will be invisible!).
Total length of each leg of the antenna is 17 feet long (each 2
inch diameter coil, one per leg, measures about 14 feet of #14 solid
insulated wire). I find the solid wire easier to work with and form the
coils. I made the coils larger to better utilize the space I had (hmmm
will that work?). My windows were of the new high efficiency plastic style
which afforded me a lot of glass and not much metal framing to worry about
interference. My LDG-100 auto tuner easily tuned 10, 12, 15, 17 and 20
meters quickly, so that was a good sign for me. Band conditions were
terrible the past 3 weekends up here (March 2009) but I managed to work
Oregon, Washington, California, Idaho, Montana, New Jersey and Ontario,
Canada with S5 or better reports each way on 20 meters. I set my output
power to 50 watts so as not to advertise to the neighbors what I was up
to! When the bands improve, I will go QRP.
On my second QSO
with W2NQ in Oregon, 3 weeks apart, John asked how my antenna experiment
was going and gave me a 5x8 report. He was a loud 5x9 with me. He was in
QSO with W7EL mobile in New Jersey and asked me to call him. W7EL and I
exchanged reports- he was 5x1 and I was a 5x3, then we both traded 5x5s a
minute later. Not bad for an indoor antenna working a mobile antenna!
Later on I added an "ugly balun" near the feedpoint for added insurance.
All in all I am pleased with the results playing with this design
and the knowledge gained experimenting with large coils which has me
thinking about a delta loop with coils now! Have fun antenna experimenting
and share your results with us! 73 de Yukon John,
KL7JR
Editors note: Try is outside on
a mast with the legs vertical!