"Dave" wrote in message
. ..
My setup is Hustler MO-2 with center loading coils and top stinger
[appropriate for each band].

For the sake of this discussion I'll refer to my 60 meter antenna. The
antenna is tuned to resonance at 5.3715 MHz using an MFJ-259B. Adding
approximately 4 inches [small spring for coil strain release] immediately
below the coil and at the top of the MO-2 has negligible effect on
resonance [a few KHz]. Now, varying the stinger above the loading coil by
4 inches causes very large changes in resonant frequency of over 300 KHz.

What's happening in the world of Antenna Physics to account for the change
in sensitivity as a function of position above or below the loading coil?

Having asked the question, I'll slide back into the internet ether, wait
for sunspots to improve, and read the opinions and comments that follow.


I don't know the "Q" of your particular antenna, but changing the whip
length will definitely have an effect! The voltage portion of the antenna
(bottom) won't make much difference, but the "current" (amperes of RF
current) will make a difference because we "tune" to resonance to match
*frequency*, and the coil and whip are what control that. Maybe I don't
explain it very well, but, I am sure others will elaborate!

73

Jerry