[Elecraft] K2 ATU question

[Augie (Gus) Hansen]

Hi Mike,

> Can't see the problem.  I have a log periodic for 18-30MHz on ant-1 and a
> vertical for lower bands on ant-2.  It does not matter if the atu stays in
> circuit and "tunes" the matched resonant antenna.  Just the same as
> matching to the dummy load.  My vertical is a good 50 ohm match on 10MHz
> but I also very occasionally press it into service on 7MHz where the ATU
> keeps the PA happy.

What you described is correct. However, a magnetic loop or other narrow-band
antenna that needs to be tuned to frequency should be run without an
auto-tuner in the transmitter. When an auto-tuner is engaged it is nearly
impossible to tune the loop correctly to resonance resulting in troublesome
matches that can stress both the loop antenna and tuner components.

I use magnetic loops with other transceivers that allow the tuner to be
disabled, but not with a K2. My K2 is used with numerous wire dipoles,
full-sized loops, an LPDA, and verticals, but not with magnetic loops. 

Gus Hansen

Email: KB0YH at arrl.net
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