[TowerTalk] Dipole questions for the Liberal Arts Major

[doc]

 > 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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