I have now been working part with different coil connections to my vertical multiband antennas for portable traffic. This is what emerged.
One coil is connected at both ends have a lower efficiency than a coil open at one end. Why? See the sketches below …
Option 1 is the connection I used in the VAP-1 and VAP-2. Here lies the spool with all his ”body” as a fixed LCR circuit with a variable drain of the arrow.
Option 2 is the part that is not even after draining passive, of course it has no real connection to the circuit without the coil is the part that is active between the drain and the wiring in the base.
It is this connection I have found most effective. Just be aware that the empty end can still get a high voltage, therefore I drill a hole in the frame where the wire end is terminated inside the body inaccessible.
LCR circuit = L, the coil has an inductance, C each lap providing a capacitance and R thread have an AC resistance – reactance.
In Option 1, you have all the time with the coil values, however, something changed depending on where the tuning ring ports so there will be a short circuit of the coil, BUT the shorted part is located in parallel to the short circuit wire and influence.
In option 2, we have no short circuit, just a drain and movement of the coil one end, the rest that remains is a passive part that hangs in the air.
Please do comments or additions in the Comments field ..