[Elecraft] (no subject)

Tue Feb 18 07:20:00 2003

From: "Sverre Holm - LA3ZA" <[email protected]>

Brent,

That particular balun is designed to withstand 500 volts RMS with a two to 
one safety factor.  The transformer action is 1:4 step up and the voltage 
would be 110 with a 1:1 SWR on the 50 ohm coax, but it could go above 500 
volts at 15 watts if the SWR got above 5:1 on the 50 ohm side.  It has an 
inductance of about 210 uhy and would have a load in parallel with the 50 
ohm load of essentially 0 + j2374 ohms on 160, twice that on 80, and so on.

I can't recommend putting it inside a K2 as there might be a problem, and 
any possible damage to the K2 would not be worth the convenience.  It will 
fit nicely into a plastic box 1" X 1.25" X 1.5."  I put one into a Sucrets 
box with a BNC on one end and two #8 screws on the other.  It is flexible 
that way.  I used it on field day at the base of an antenna fed with open 
wire line and a coax the rest of the way to the transceiver.  It is 
designed and tested for 100 watts at a SWR of 5:1 or less.

To: "'WB4X (Brent Sutphin)'" <[email protected]>,
<[email protected]>
Subject: RE: [Elecraft] W1CG Balun in K2
Date: Mon, 17 Feb 2003 18:24:58 +0100
Say that you put the balun in the K2 as below, but need to use the K2
with a coax antenna. Of course you could use the other antenna
connector, but let's not do that now. As you connect the antenna, the
balun will be in parallel to the antenna, and be unloaded on the high
impedance side. Will that have any adverse effects? - will it present an
undesired load to the K2, or will it be bad for the balun, e.g will
there be high voltages in the balun that could do harm?
In an ideal world this should not make any difference, but how is this
in the practical world?

73, Chas, W1CG
K2 #462