Agree on the NVIS which we used to consider normal 80 and 40 meter
antennas for all but the richest hams. I don't think the extreme of 6'
with its hazards is necessary, 20 feet works fine for me and for my
club. One time we were at a university horticulture farm complete with
multiple wind mills, a couple on 150' towers about 150 feet apart. Our
tower climber scrambled up those and hung an 80 meter dipole 120 feet
up. It was great at putting a signal into California (from Iowa) but
didn't put an outstanding signal there and was useless for surrounding
states where the biggest number of FD contacts are made. We've had
better 80 meter FDs with a 500' loop strung ten or twelve feet high
through the woods or with an inverted V hung from a 30' tower.
I used an extended double Zepp at home for decades from 160 through 2m.
It had several different feed lines in the lifetime of its supports and
didn't seem to work differently when I raised the feed point from 30' to
55' working my dad about 400 miles distant. It can provide odd enough
feed impedances that limited range tuners won't tune it. I used home
made link coupled tuners all that time.
73, Jerry, K0CQ
On 4/11/2011 3:12 PM, Stuart Rohre wrote:
> John, I hear you on pole set up for FD!
>
> We got great results from Horizontal Delta loops as our club FD migrated
> from big Vee beams, to Extended Double Zepps for 80m used on higher
> bands, to today. We did loops thate were rectangular horizontal,
> square, n polygon, and finally, for simple set up, 3 legged horizontal
> loops. They are made up of 3 individual segment wires. Thus, you are
> only putting up one wire at a time on a pole or support.
> You put up one wire and leave a pigtail at each end, hanging out the
> insulator. Join those pigtails after you have two wires at a corner,
> with wire nuts, point closed end up to shed rain and dew.
>
> Has worked great for us for almost 10 years. We only put them about 20
> feet above ground, as we use these loops for 20m and up. 20 feet was
> the size dictated by our lightweight extension ladder. This ladder is a
> flip over from an A frame ladder, so it is the lightest type you can
> haul around a field Day site.
>
> We mainly use NVIS low dipoles at no more than 6 feet high, well marked
> with orange tapes, for 80m and 40m. The darn thing about them, they
> still work skip at night! To west coast from TX.
>
> Our antennas are in the keep it simple and low labor now.
> Our loops were able to use light poles that existed at our former FD
> site. Now, we have been going back to EDZ doublet on a single pole.
> And an inflatable mast with integral 2m at top and supporting a HF
> inverted Vee dipole with wide band tuner.
>
> -Stuart Rohre
> K5KVH
> _______________________________________________
>
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