[Elecraft] Switching P/S Horror Stories

[Charles Greene]

At 02:45 PM 4/5/2002 -0800, Ron D' Eau Claire wrote:

>Keep in mind that it is not the ladder line itself that is causing the
>interference, but the fact that the currents flowing in the wires are not
>balanced. If you have the ladder line balanced, it will not pick up or
>radiate r-f.
>
>If you are using some sort of off-center fed antenna, then the ladder line
>is  being used as part of the radiator, not as a feed line. Windoms are one
>of the common off-center fed doublets. They use the ladder line as a
>integral part of the radiator to provide vertical radiation. Those designs
>bring the radiating and receiving part of the antenna right down to the ATU.
>You should not expect it to be any less sensitive to noise pickup or
>radiation than a single-wire feeder.

>--snip--

Very interesting, and when you think about it, obviously true.  I was 
thinking about replacing my G5rv with an 80 meter OCF (Windom) and was 
debating whether to feed it with coax with a balun at the antenna top, or 
300 ohm feedline with a balun at the bottom.  I had an OCF installed for a 
long time until a storm blew it down and I have used a similar one for 
field day, but I have always used a 4:1 balun at the top where a mast 
supports the balun.

Tnx for pointing that out RON.  I probably would have installed it with the 
300 ohm feed line and wondered why it didn't perform like the book said it 
should.

BTW, the reason for installing the OCF is: 1.  My lot seems designed for an 
OCF: a bit short for one side of the G5 so I have to bend it over but just 
right for the OCF.

2.  I have a vertical which performs about the same or better except on 80 
and I want to improve performance on 80.

Oh yes.  The vertical is much quieter than the G5.  I attribute that to the 
fact that the G5 is a little closer to and of the same polarity as the 
power distribution lines in the rear of the property.  I don't seem to have 
a problem with switcher noise, to get back to subject.  I just have that 
little 2.4 amp switcher I use with my K2 that seems pretty quiet.  One 
thing about it, it's encapsulated so to speak and there's no way to add 
another ground and introduce a ground loop.



73, Chas, W1CG