[Elecraft] ladderline and balun question

[WILLIS COOKE]

Don, when it comes to ladder lines and baluns the only real expert was Jerry Sevick and he has gone to a better place where they only use resonant beam antennas.  Take anything anyone is living says about open wire feeders and baluns with a grain of salt.  Put your antenna back like it was when it worked.  Ignore further advice from the living.  Since I am still living, more or less, feel free to ignore this advice as well!
 
Willis 'Cookie' Cooke 
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart


________________________________
 From: "goldtr8 at charter.net" <goldtr8 at charter.net>
To: elecraft at mailman.qth.net 
Sent: Wednesday, January 11, 2012 3:12 PM
Subject: [Elecraft] ladderline and balun question
 
Gents,

I have a ladder line and balun question that I hope someone can guide me 
thru.

I had a good working antenna system with two antennas.  First being an 
Alpha Delta Dipole and the second a 2WL 160m loop antenna at 40 ft in 
the air strung in trees.  So the wire does touch the trees.

Dipole is fed with coax and choked at the feed point and the loop was 
fed with 60 ft of ladder line to a 1:1 current balun then 25ft coax to 
the shack tuner.  Then the amp and radio.   This combination was working 
real well no RF problems in the shack.

I was advised that I would obtain better results for better SWR at 
resonance and easier matching if I removed the 1:1 balun and went to a 
4:1 balun.  I made this change with everything else being the same.  I 
now had RF in the shack again.

I then added an isolation balun to the system by adding 6ft coax from 
the output of the 4:1 to a balun designs 116du which is supposed to have 
4500 ohms of choking impedance on 160m and over 5000 ohms choking 
impedance  on 80 and 40 meters.   This did not eliminate the RF and I am 
still having problems.

So here is the question, is it possible that with the combination of 
length of the ladder line at 60ft plus the 6 ft plus 25 ft of coax I am 
at a feed line length that will be a problem no matter what I do.    I 
keep looking at the internet to try and figure this out but I am 
confused as some information I find says it only applies to 1:1 baluns 
or other factors.

So anyone who can help me understand this feed line question I will be 
greatly appreciative.

Thanks
Don


~73
Don
KD8NNU


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html