I have noticed that some receivers have a tap in the windings of the ferrite coil. It is about 20% along the length of the coil. I would like to know the purpose of the tap. Currently I am working with a Tecsun DR-920. It is a chip-based receiver and so chasing the circuitry achieves nothing unless you know the internal workings of the chip. I also have the MW loopstick from a low performance radio that was pulled to pieces when it failed and it too has a tap on the loopstick winding.
Is this tap for impedance matching purposes or could it be the "tickler" portion of a q multiplier?
Any ideas or contributions most welcome.
All the best,