Asimov wrote:
Cecil, an infinitely long antenna is simply an impedance transformation
between different mediums. i.e. wire to free space.

We know one of the impedances to be 377 ohms.
Question is, what is the other impedance?
--
73, Cecil, http://www.qsl.net/w5dxp

It's so simple to derive the value of 73 ohms.
Just divide 146 by 2.
Or multiply 36.5 by 2.
There are other ways of doing it.

Cec, if you divide the well-known 377 ohms by 5.164, which is the
square-root of 26.67, you get precisely 73 ohms.

What's the problem?
---
Reg

Reg Edwards wrote:
Cec, if you divide the well-known 377 ohms by 5.164, which is the
square-root of 26.67, you get precisely 73 ohms.

But, but, but, Reg, you said the feedpoint impedance of
an infinite dipole is 1200 ohms, or some such. That's
very close to 377 ohms times pi.
--
73, Cecil http://www.qsl.net/w5dxp

But, but, but, Reg, you said the feedpoint impedance of
an infinite dipole is 1200 ohms, or some such. That's
very close to 377 ohms times pi.
================================

Cec, for once, you ageed with me.

But, but, but, coincidences in arithmetic are certain to occur.
----
Reg.

"Cecil Moore" bravely wrote to "All" (29 Sep 05 15:25:42)
--- on the heady topic of " 73 Ohms, How do you get it?"

CM From: Cecil Moore
CM Xref: core-easynews rec.radio.amateur.antenna:217594

CM Asimov wrote:
Cecil, an infinitely long antenna is simply an impedance transformation
between different mediums. i.e. wire to free space.

CM We know one of the impedances to be 377 ohms.
CM Question is, what is the other impedance?


I think it is whatever you want it to be because it is a transformer.
Varying Rs would only affect the pattern.

A*s*i*m*o*v

.... Thank Thor Friday Nears!

On Fri, 30 Sep 2005 06:11:10 GMT, "Asimov"
wrote:

I think it is whatever you want it to be because it is a transformer.
Varying Rs would only affect the pattern.

In standard antenna parlance, the "pattern" is unaffected (aside from
magnitude, and then only by consequence of mismatch) by
transformation.

73's
Richard Clark, KB7QHC