Hi Kelvin,
I have both of the Alex magnetic loops.

I use the MFJ 212 noise bridge to tune it.

This is supposed to be a device that will tune a manual tuner and makes a
noise when you have tuned the tuner to an approximate 1/1 swr.

It seems to work ok with the loops.

Even though the loops are not manual tuners you still have to tune the
little box that comes with them for lowest swr.

I use the mfj 212 between my transceivers and the magnetic loops.

I had thought about getting one of the more expensive MFJ magnetic loops but
they send a signal with current down the coax to move the motor for tuning.

In this case MFJ says specifically not to put any sort of device between the
loop and the transceiver.

I suppose one could tune for the maximum noise of the motor and hope that
then the loop is tuned and resonant.

This seems chancy though.

Gary Lee one of the other folks on this list has the larger Alex loop and
has successfully tuned it by ear.

Wimo Electronics in Germany sells a magnetic loop for over $1200 US dollars.

It comes with a keypad enabling the user to enter the wanted frequency and
then the loop is supposed to tune itself to resonance on the wanted
frequency.

I'd love to go to Dayton sometime and see one of those.

Hope these comments help.

Best 73,

Eric
KU3I