And if one needs a heavy duty solution for installations with a folling
branches and trees then 2 of WD1A at your favorable spacing is a good choise
2 x WD1A 500 mm apart is very close to 800 ohms and easy to match
2015-06-07 23:09 GMT+03:00 jeremy maris <jeremy@maris.plus.com>:
> Yes WD1A works very well with the conductors strapped. I've built a 300m
> long reversible beverage up at about 2.4m with two parallel runs of
> strapped WD1A about 50mm apart.
>
> Impedance of this line is around 450 ohms at that spacing so transformer
> design is simpler than one twisted WD1A and losses considerably less.
>
> Jeremy G3XDK
>
>
> On 7 Jun 2015, at 16:55, Roger Parsons via Topband wrote:
>
> > I know that WD-1 and WD-1A wires are not very good for two wire
> transmission lines due to their high attenuation. I wonder however whether
> they are OK with the conductors strapped as Beverage wires? WD-1A has quite
> a few advantages for the bush where I run my antennas - it is strong, it is
> quite light, it is very nice and easy to run out, and it fits through
> electric fence insulators.
> >
> >
> > I presume that its poor performance as a balanced line is related to the
> copper wires twisting with the steel ones meaning that for some of the time
> current is passing through the steel wires due to skin effect. On the other
> hand I can't see how it can be worse than galvanised steel wire or electric
> fence wire.
> >
> > 73 Roger
> > VE3ZI
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
--
Andrey Fedorishchev,
RA6LBS
www.RA6LBS.ru
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|