vertical antenna loading coil vs toroid
On Mar 28, 3:00*pm, wrote:
wrote:
I am doing some design with vertical antennas for the low bands
40/80/160M. I require a somewhat large reactance on the element to
help load it on 160M, (40&80M) are working somewhat satisfactory now
with the design i am using. The required reactance that i need and the
size it would be using a coil (with the materials that i have right
now) *may not last a winter storm in VO1 land when loaded with ice or
snow in 90km/h wind, so my question is, has anyone had experience
using a *toroid wound with the correct amount of reactance installed
on the element to to achieve resonance instead of a coil and how it
has been for them.
I have something simular and used a FT-240-61 torroid which I happened
to have to build a tapped inductor with a pair of relays to switch it
in/out for 80/160.
The antenna analyzer and radio say it seems to work OK.
Just be sure to pick a material appropriate for an inductor at those
frequencies and a size appropriate for the power you intend to run.
--
Jim Pennino
Remove .spam.sux to reply.
Thanks for the information, nice to see others have done some work
with this in the past.I could do the switch relay and use the same hat
on 160 as i am now on 80, this overhaul length would be about 45 feet
not bad on 80 but i'm think a little short for efficiency on 160, with
the insulator i have on top of the 45 feet i can go another 12 feet to
the 160M hat. 57 feet overhaul to see how that works out. I do have an
option for an 18 feet fiberglass on that for 75 feet total but would
like to stick to 57 feet max any higher than that it will be quite
noticeable with the sun on the fiberglass over the tree line, i will
consider though your thought maybe not worth the gain in efficiency to
go the other 12 feet to the 160M hat, its maybe about 8-10 electrical
degrees in vertical radiator to the 160M top hat, thanks again great
info,73 vo1bbn
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