Pete KE9OA wrote:
If we are talking about a ferrite loopstick antenna, and if the coil is
wound on a cardboard former, the coil can be slided on the form to peak the
sensitivity on the lower end of the band. The trimmers peak the high end of
the band, and if the tuning capacitor has slits in the outer plates,
sections of these plates are bent to peak the sensivity in the middle of the
band, typically at 1000kHz. This is known as three-point tracking.
With some loopstick antennas, this is not an option because the wire is
wound directly over the ferrite form.

************************************************** *********************************************
The above is a much better tracking method if you have air variable
tuning capacitor, and the right kind of loopstick. The radios I was
referring to are the cheapies that use the tiny sealed variable cap,
glued loopstick coil, and made in the last 30 years. These radios only
permit one adjustment to improve alignment: the oscillator coil. I
don't recall when the industry abandoned the air variable, but I think
it was around 1975. Those radios might need a different method of
alignment as they might still have coils and trimmers long gone from
the scene. I have a few 365 mmfd 2-gang variables in my junk box that I
am thinking of putting on ebay because of the high prices they fetch
now. Does anybody still make them?