Total posts : 45366
Sure, adding or subtracting even partial turns <EM>will</EM> affect tuning.
Here’s a calculator which might help: http://hamwaves.com/antennas/inductance.html
The window thing is a bit wierd, dunno how tuning affects it….i.e., does the metal frame connect all way ’round, acting at least a little like a direct-coupled loop antenna? You have to determine direction, i.e., …What does more or fewer turns from the 72-turn mark do to the signal?
You aren’t likely, ‘cept by accident, do get it to resonate perfectly from taps. In one of my systems, a Sharpie pen width of length (about 1/16″ or less) made a difference; above or below it caused the signal to deteriorate rapidly from resonance.
That being the case, you could adjust final length with a telescoping antenna used as a stinger, or adjust resonance with a large vernier variable air cap….or air-coil-over-air-coil movement coupling….or a small diameter air coil carefully sanded (through the coating) across its turns with a stylus for tuning….or….???
