I don't want to rehash my well known observations of a well known ....
I have a vertical that has a doughnut of silence that extends from approx 25 miles to between 125 and 175 miles. That's just because it's a vertical.
I have observed another vertical that has multiple concentric rings of silence. No surprise this coincides with the nulls at the antenna.
I know a huge sports field complex and a man lift containing yours truly and a sensitive , powered field strength meter (calibrated? you really are kidding, right?) does not an antenna range and scientific measurements make. However the lobes and nulls were found and as the angles were all that was needed I called it a day and returned the man lift before anyone noticed .
I have several horizontal wires that are better at less than optimal (says who) height and others that get better with height. It's experimentation, it's what we do.
Some general observations over the last 40 years.
Any gain you get in a desired direction or elevation is taken from somewhere else. Where are the nulls?
HF isn't Voodoo, it behaves as it should , except when it doesn't .
Any HF horizontal wire follows well understood patterns.
Multiband horizontal wires , OCFD, Fan dipole, Loops, and loaded elements do not.
Non resonant horizontal wires have two significant issues. First is when fed at voltage maximums vs frequency. Second when fed close to resonance. In the first case it's all about kilovolts wandering about. In the latter case it's passing through resonance RF getting into the shack.
Horizontal multi element beams, quads, Gizmatchy, Yagis follow well known formulas that don't work in practice. Experimentation is the key.
LPDA's Log periodic dipole arrays do follow design formulas.
EFHW (end fed half wave) Go ahead , I'll watch (and laugh)
Understand the difference between impedance , VSWR and resonance.
Low VHF and VHF are two entirely different things. 50MHz is it's own deal. once above 136MHz height wins.
Parabolas much below 1GHz are a joke .
Monopole antennas and any vertical shortened to a small percentage of a quarter wave are a radiating dummy load.
Last but not least what ever you think you prepared, engineered, built for mother nature , mother nature has something all together different in mind.
Look , it isn't rocket surgery but it is science.
...and experimentation.
I have a vertical that has a doughnut of silence that extends from approx 25 miles to between 125 and 175 miles. That's just because it's a vertical.
I have observed another vertical that has multiple concentric rings of silence. No surprise this coincides with the nulls at the antenna.
I know a huge sports field complex and a man lift containing yours truly and a sensitive , powered field strength meter (calibrated? you really are kidding, right?) does not an antenna range and scientific measurements make. However the lobes and nulls were found and as the angles were all that was needed I called it a day and returned the man lift before anyone noticed .
I have several horizontal wires that are better at less than optimal (says who) height and others that get better with height. It's experimentation, it's what we do.
Some general observations over the last 40 years.
Any gain you get in a desired direction or elevation is taken from somewhere else. Where are the nulls?
HF isn't Voodoo, it behaves as it should , except when it doesn't .
Any HF horizontal wire follows well understood patterns.
Multiband horizontal wires , OCFD, Fan dipole, Loops, and loaded elements do not.
Non resonant horizontal wires have two significant issues. First is when fed at voltage maximums vs frequency. Second when fed close to resonance. In the first case it's all about kilovolts wandering about. In the latter case it's passing through resonance RF getting into the shack.
Horizontal multi element beams, quads, Gizmatchy, Yagis follow well known formulas that don't work in practice. Experimentation is the key.
LPDA's Log periodic dipole arrays do follow design formulas.
EFHW (end fed half wave) Go ahead , I'll watch (and laugh)
Understand the difference between impedance , VSWR and resonance.
Low VHF and VHF are two entirely different things. 50MHz is it's own deal. once above 136MHz height wins.
Parabolas much below 1GHz are a joke .
Monopole antennas and any vertical shortened to a small percentage of a quarter wave are a radiating dummy load.
Last but not least what ever you think you prepared, engineered, built for mother nature , mother nature has something all together different in mind.
Look , it isn't rocket surgery but it is science.
...and experimentation.
