[Lf] LF: Automatic ATUs]

[Andre' Kesteloot]

vernall wrote:

> 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