[Elecraft] Non-Resonant Antennas and Chokes

[Victor Rosenthal 4X6GP]

I have three suggestions:

1) If you are feeding the antenna at the precise end of the wire, move 
the feedpoint out a few feet. That's because you need "the other half of 
the antenna." Because of the high impedance at this point, only a few 
feet are needed.

2) Don't connect one side of the ladder line to a ground rod. It doesn't 
help and will probably hurt. If you want to ground something, ground the 
shield of the coax at the tuner.

3) Use a good 1:1 balun designed for antenna tuner use between the tuner 
and the ladder line. Yes, people say you should use a 4:1 balun. Don't 
listen to them. The impedance at the end of the ladder line will be low 
on 40m (it's transformed by the near 1/4 wave ladder line). If you use 
the antenna on other bands it will vary all over the map.

73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/
On 16/01/2019 4:15, John Pierce wrote:
> I haven't read all the comments on this thread and thus may requesting
> redundant info.  My antenna, for 40 mtr's, is a 67' wire up about 25'.  I
> have 30' of 450 ohm ladder line connected to the end of the antenna and
> bringing the antenna into my basement.  So I guess you could say that I have
> a non-resonant end fed Zepp.
> 
>   
> 
> I can check the impedance at the end of the ladder line, where one side is
> the antenna and the other side is connected to a ground rod at the point of
> entering the house.   I can measure the impedance of the antenna in the
> basement, using Mini60 without an antenna tuner .  The ladder line is then
> connected to a MFJ 926B remote antenna tuner  The tuner is fed by about 30'
> of RG58 coax from  my transmitter.  When I see a reactive component to the
> impedance of the ladder line, without the tuner connected, should I have
> some choke inserted in one side of the ladder line or not?  Should the tuner
> be able to handle the reactive component?
> 
>   
> 
> John
> 
> AD2F
> 
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