HI Gary,
I was talking about the Mfj-212 box for tuning a manual tuner.
It emits pulsed noise when you have tuned the tuner correctly to close to a
1/1 swr.
Vectronics also makes a similar box.
I have the model number at work.
I am thinking this might be used to tune one of the magnetic loops.
When I have got lots of time to play such as a holiday weekend I'll have to
try inserting the 212 between my transceiver and one of my Alex loops and
see if it works like I think it might.
Eric
KU3I