Antenna impedance calculator

Are you a scientist? What kind?

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John Larkin      Highland Technology, Inc 

The best designs are necessarily accidental.

Am 30.12.2020 um 16:56 schrieb snipped-for-privacy@highlandsniptechnology.com:

Theoretical electrical engineering and theoretical communications engineering, mathematics and physics.

Amateur?

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John Larkin      Highland Technology, Inc 

The best designs are necessarily accidental.

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** Leo B is a *scientist* in the same way an Alchemist is one.

.... Phil

Greetings Leo,

My goal is to derive the governing equations behind Ben Schueler's

433 mcy antenna:

Those governing equations will then be used to create a similar antenna for 315 mcy.

? / 4 in free space for 433 mcy is ~ 17.3 cm

Shueler's article shows a 7 cm overall length for his 433 mcy antenna, excluding 16 turns.

The BALANIS calculator on your webpage returns:

6.7136 - 242.7839j for 433 mcy 1.9942 - 224.0828j for 315 mcy

Then those results are fed into octave:

octave:1> abs((6.7136 - 242.7839i) / (1.9942 - 224.0828i)) ans = 1.0838

Does it make sense to use the above answer as a coefficient to determine the overall length of the 315 mcy antenna?

1.0838 * 7 cm = 7.5866 cm

If so, a reactance ratio can be derived to determine the number of turns on the 315 mcy antenna, no?

Danke,

--
Don, KB7RPU 
There was a young lady named Bright Whose speed was far faster than light; 
She set out one day In a relative way And returned on the previous night.

Am 30.12.2020 um 19:37 schrieb Don:

No, sorry, such a way to calculate the 315 mcy antenna is surly wrong.

I don't know what were Ben Schueler's thought designing such antenna, but there are no linear coherence to a 315 mcy version.

No linear coherence at all, it turns out. Among other things, antennas such as Schueler's are known as "loaded whips." And most, if not all, loaded whip designs originate with a September 1974 QST article. Here's the tentative governing equation, which will be fleshed out soon and published to a webpage:

Some interesting facts were gleaned along the way to the equation:

• The loading coil is the most critical part of a loaded whip antenna.

• Any old length of antenna greater than ? / 2 can be used. (Ergo the cognitive dissonance in Schueler's paper, where lengths are specified to a tenth of a millimeter before the lengths are arbitrarily bent.)

• The antenna's /volume/ plays an efficiency role. Ergo the diameters present in your antenna impedance calculator, for instance.

Danke,

--
Don, KB7RPU 
There was a young lady named Bright Whose speed was far faster than light; 
She set out one day In a relative way And returned on the previous night.