[Elecraft] Re: KAT100 with Ladder Line

[Solosko, Robert B (Bob)]

Peter,

	I agree- my 100' fan dipole is fed with about 70' of ladder line
into a current balun, which is then connected to my KAT100 through about
5' of RG-8. The balun is attached to the side of my house just outside
the window and the coax brings it into the house. Since at 100w, a
significant mismatch could cause the balun to heat, I made my own
current balun using a pair of FT43-240 cores which has a much higher
capacity than the small core used in the BL2. I followed the basic BL2
circuit diagram, replacing the switch with an external jumper so I could
try it at both 1:1 and 4:1. For my antenna, the 4:1 ratio worked better
- the KAT100 will get the SWR down to 1:1 on the transmitter side on all
bands from 10m to 80m, and on the lower 2/3rds of 160m. I seem to have
no problems getting out, having worked most of Europe (which is the
direction favored by my dipole), much of South America, and most of the
US & Canada on SSB. Whatever losses there are in the balun seem to be
small, and more than compensated for by the use of the very low loss
ladder line.

Bob W1SRB

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Joe-aa4nn
Sent: Friday, November 16, 2007 10:04 AM
To: Peter Wollan; elecraft at mailman.qth.net
Subject: Re: [Elecraft] Re: KAT100 with Ladder Line

Hi Peter,
Try not to worry too much about feeding balanced lines.
Get the Elecraft BL2 and hook it to the balanced line.
Connect a 2 or3 foot piece of coax from the BL2 to your rig.
Tune up and away you go.  If the balun tends to get a little warm, just
cut off 5 or 6 feet of the balanced feedline and give it another go.

You don't want to connect balanced line directly to KAT2.

73 & gl,
de Joe, aa4nn

----- Original Message -----
From: "Peter Wollan" <wollan at mayo.edu>
To: <elecraft at mailman.qth.net>
Sent: Friday, November 16, 2007 9:50 AM
Subject: [Elecraft] Re: KAT100 with Ladder Line


> Please, I'd like some more discussion of this question.  I've seen  
> before that baluns on ladder line can be lossy, but I'm not about to  
> get a balanced tuner, so it doesn't really help.  What happens if you

> connect the balanced line directly to the KAT100?  Or, in my case, to

> the KAT2?  I haven't had any problems so far -- maybe low power makes

> a big difference, or maybe I've just had antennas which were  
> reasonable in some way.  I gather it's possible to get unpleasant  
> currents on the case, mic, or paddle.  Is that exactly the condition  
> in which the balun will be lossy?  Does connecting the ground screw  
> on the KAT2 (or the one on the balun?) alleviate the common mode  
> current problems?
> 
> Peter N8MHD
> 
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