James Moritz wrote:

Dear LF Group,
        Many thanks to all those who responded to my request for
information regarding automatic ATUs - I now have several leads
to go on for my research.

Cheers, Jim Moritz
73 de M0BMU

James,

Could you please consider putting a summary list on the reflector?

I have been considering making an "automatic fine tuner" for LF, for
reactance compensation only.  I believe that variation of the reactive
component of impedance is what is mainly involved with short term
changes over wet/dry/ice or whatever environmental conditions.  Once the
LF antenna has been "tuned and matched" using the likes of a (big)
loading coil with taps or L match, the relatively small variations in
reactance with changing conditions could be handled with a motor driven
variometer (say 50 uH range).  This is a whole lot simpler than having
the whole tuner automated (more suited to multi-band and multi-antenna
scenarios, but not common on LF).

73, Bob ZL2CA