Reg Edwards wrote:

There was an article in RadCom some years ago describing an
auto-tuning
Top Band vertical, which used a simple inline phase detector and a
little DC tuning motor.

==================================
Ian,

A magloop is an altogether different kettle of fish to a top-band
vertical. For a start, the Q of a magloop is in the order of 1000.
For a top-band vertical it may be about 50. For most antennas it is
about 10.

Not fundamentally different - it only means the magloop tuning will be
more sensitive. The servo will still try to drive the system to
resonance at zero phase angle.

The overall gain around the servo loop will be the product of the
antenna Q, the mechanical gear ratios and the voltage gain in the
electronics. The last of these can be adjusted with a single pot. If you
have a higher antenna Q, you simply need less voltage gain.

What I would like to know is has anybody ever made an automatic tuner
which works with a magloop. Or has manufactured one for sale?

Don't know, never looked.

By the way, thanks for the Teslar papers although I am unable to run
the programs.

(I only downloaded the program for coupled inductors, but haven't
studied it yet. It ran OK, after having extracted all of its files into
a real directory; it won't run from inside the .zip 'directory'.)


--
73 from Ian G/GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek