[Elecraft] PlugIn Balun for K2/Kat1 ATU

[Stuart Rohre]

Use of a 1:1 balun or cable choke on the input side of a floating transmatch
would seem to be the better thing to implement in tight spaces of a K2.

The advantages of input side balance device such as the cable coax choke, is
that both sides see 50 ohms at all times when the transmatch is in
adjustment.  Voltages are lower than output baluns of the 4:1 type.  With
high current, low impedance, you might not couple into the case or nearby
conductors as much as a high step up balun.  Losses of a 1:1 device are
purported to be lower, and certainly minimal using a cable choke.

Most autotuners are unbalanced circuits I believe, what effective unbalance
amount this would be to balanced feeders and antennas has not been covered
in the literature to any well known degree.  I think there are some web
postings on antenna web sites about percentage imbalance seen when feeding
parallel line to such antennas as the end feed Zepp, but effects of L net or
pi net auto tuners have not been covered that I could find.

Anyone have any data on that balancing means?
72,
Stuart K5KVH