> Tim Duffy K3LR wrote:
> Open wire fed dipoles having enough length to cover to 3.5 MHz (minimum 140
> feet,
> center fed), really work well.
>
> I make mine 175 ft long (split in the middle for the open wire feed).
> At this length (longer than 1/2 wave at 80 meters), it is two 5/8 wave
> lengths in phase for 40 meters. It has real gain
> on 40.
>
> Although the 4:1 balun followed by lengths of coax method works,
> I really prefer the Johnson matchbox for matching the open wire fed
> dipole direct to the radio (or amplifier) with minimum
> coax after the tuner.
I have maintained two different wire antennas for years.
One is a 280 foot (approx.) multiband 450 ohm slotted commercial line
fed antenna I have tuned via a massive homebrew tuner. Because the
new QTH is steel it will either be fed via a short length of coax,
to minimize the impact of proximity to steel, or via a remote tuner
(Heath SA-2550).
The other is a 140 foot 80M coax-fed dipole because 80 is a favorite
band not covered by a beam and thus I wanted something oriented
differently than the multiband dipole/doublet.
Getting either high enough to not be NVIS on 80 and 160 is definitely
a challenge.
--
Thanks! & 73, doc kd4e
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KD4E =========================================
West Central Florida
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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