1. High Q coils did not outperform a LOW Q coil in field strength tests.(no difference!)
A 75m Texas Bugcatcher (high-Q coil) outperforms a 75m hamstick (low-Q coil) by about 10 dB - measured results.
2. Coil positioning or coil distance from the base had more impact on efficiency
Already known for decades that center loading is better than base loading.
5. Length of the mast below the coil had a huge impact on performance.
Already known for decades because that's where the high current area exists.
6. Size of the vehicle has the most impact on ground resistance
Already known for decades
8. Magnet mounts reduced field strength significantly.
Already known for decades
9. Cap hats and coil metal ends had little impact on field strength
In the measured CA mobile 75m shootouts, a good capacity hat increased the radiated signal by about 2 dB having essentially the same effect as lengthening the element below the coil.
14. Coil current measurements were performed! "Current tapers from the bottom to the top of the loading coil"
It is apparent from The ARRL Antenna Book
that "Current taper" in a shortened loaded standing wave monopole is not well understood by the ARRL (or the average ham). In a high-Q loading coil, virtually all of the current taper is caused by the phase difference between the forward traveling wave and the reflected traveling wave on the standing-wave antenna. The total current is the phasor sum of the forward current and the reflected current and is primarily a standing wave. The purpose of the loading coil is to put the reflected wave in phase with the forward wave at the antenna feedpoint resulting in antenna resonance. Here's a representation of the forward and reflected current components:
If1 is the forward current flowing into the bottom of the loading coil from the feedpoint. Ir1 is the reflected current flowing out of the bottom of the loading coil back toward the feedpoint. If2 is the forward current current flowing out of the top of the loading coil toward the tip of the whip. Ir2 is the reflected current flowing into the top of the loading coil after being reflected from the tip of the whip.
Here's what the total current phasors look like assuming the antenna is base-loaded, the phase shift through the loading coil is 45 degrees, and for the purpose of simplicity, that the entire antenna, including the coil, is lossless.
Even assuming the coil is lossless and the SWR on the standing wave antenna is infinite, the current taper still occurs. The total current at the top of the coil is 71% of the total current at the bottom of the coil as it is in the model that follows.
The current taper is not primarily a loss of current to radiation or losses. It is primarily a simple phasing function that occurs between the forward current wave and the reflected current wave on the standing-wave antenna. That's why it is known as a standing-wave antenna
.The results are very similar whether we assume the system is lossless or not.
If we extend the whip above the coil by 1/4WL, the current taper will reverse itself resulting in a greater magnitude of total current at the top of the coil than at the bottom of the coil, i.e. apparently more current flowing out of the top of the coil than is flowing into the bottom of the coil. That should be enough to to convince one that current taper is primarily the result of phasing between the forward current and reflected current, not the result of losses or radiation. Here's an EZNEC model of both antennas.
How can the current into the bottom of the coil on the long antenna be 1.3 amps while the current out of the top of the coil is 2.1 amps??? Doesn't that violate some current law??? Yes, in the lumped circuit model but NOT in the distributed network model.
Some well-known gurus have promoted the lumped circuit concept that the RF current into a coil is equal to the current out of the coil in magnitude and phase but that concept just doesn't work for distributed networks! A large 75m air-core mobile loading coil, e.g. a 75m Texas Bugcatcher coil, is a distributed network which is an appreciable percentage of a wavelength long (usually in the ballpark of 10% of a wavelength).
What we can correctly state is that the forward current into a loading coil is approximately equal in magnitude
to the forward current out of the loading coil and the reflected current into that loading coil is approximately equal in magnitude
to the reflected current out of the loading coil. Most of the current taper from end to end in a large air-core loading coil is the result of the respective phase shifts (delays) in the forward and reflected currents flowing through the coil, not the result of losses or radiation.
We can also correctly state that the phase shift in the total
standing wave current from end to end in the coil is very close to zero. Anyone familiar with a standing wave knows that a pure standing wave doesn't change phase over each half-wavelength of wire (or loading coil). In the phasor diagram above, one can see that the phase of the total current at the bottom of the coil is the same as the phase of the total current at the top of the coil.