[Elecraft] Home made Sigma-GT5 & KRC2 or SGC?

[George, W5YR]

Darrell, consider the source of loss in a simple coil of coax - say, ten
turns about six inches in diameter - which will do an excellent job of
decoupling a balanced line from a run of coax.

Roy Lewallen W7EL has demonstrated that a balun on the input of a tuner is
subject to the same stresses or more that if used at the output.

I use W2DU-style bead baluns of my own design which have a measured loss of
about 0.1 dB at 14 MHz. I have three antennas fed with ladder line. Each
transitions to coax via a W5YR bead balun and thence to the tuners. Tuner
loss at 14 MHz measures about 0.5 dB on average.

Baluns need not be lossy unless designed that way. Same with tuners, none of
which have fans or ventilated cabinets for cooling.

73, George W5YR
Fairview, TX
w5yr@att.net
http://www.w5yr.com


----- Original Message ----- 
From: "Darrell Bellerive" <ve7cla@shaw.ca>
To: "Don Wilhelm" <w3fpr@isp.com>; "Elecraft Email List"
<elecraft@mailman.qth.net>
Sent: Saturday, March 20, 2004 6:29 PM
Subject: Re: [Elecraft] Home made Sigma-GT5 & KRC2 or SGC?


> I know that this has been discussed before on the mailing list, but no
> matter how well designed a balun is, I just don't believe that it will
> be very efficient when used with a non-resonant doublet for multiband
> operation from 160 to 10 meters. Add a long length of coax and the
> losses further increase. The balun must be on the transmitter side of
> the tuner for the lowest losses, hence the need for a remote tuner, or a
> QTH where open wire feeder can be used.
>
> Darrell VE7CLA K2 #1973
>
> On Sat, 2004-03-20 at 16:16, Don Wilhelm wrote:
> > Folks,
> >
> > A balun will take care of the balanced part (although I must admit that
the
> > balun impedance should be quite high with high impedance loads) - but my
> > request os for an Elecraft REMOTE tuner.  It would solve the multiband
> > problem at my QTH.  I have a 150 ft. run of coax from the shack to a
place
> > where I can locate a tuner (XYL says no antennas or feedlines where she
can
> > see them from the windows!!!)
> >
> > I am currently addressing the situation by building dedicated antennas
for
> > each band, but it certanly would be nice to have one multiband antenna
that
> > had an automatic tuner made by Elecraft - I know, I can buy an LDG, but
> > don't want to do that.
> >
> > 73,
> > Don W3FPR
> >
>
>
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