"Reg Edwards" wrote in message
...
The program takes into account antenna diameter. Does Kraus?

Yes. My post said length/diameter = 472 (One thing I don't like about the
way Kraus wrote his book is that he gives the formula for only one part of
the feed impedance (R or X) and a diagram for the complex impedance. He
then refers you to someones paper somewhere for the 'complete' formula.. I
have it around here but it would take 2 days to find it.)


And is he on the same band?

In the diagram I was interpolating from the dimensions are in wavelengths.

Is he at the same height above ground? What sort of ground or radial
system does he have?

It is an infinite perfect ground plane---ground mounted. (We are talking
about a 5/8 wave vertical remember).

Have you interpolated correctly?

Probably not.


Have you understood what Kraus is saying?

Yes.

Is the loading coil in the same location?

No 'loading coil' in the Kraus example. He is discussing the feed point
impedance. A loading coil would be either across or in series with the feed
point.

Is the feedpoint at the same place.

Since the original post concerned a 5/8 wave vertical, I assumed it is at
the bottom, which is what Kraus is discussing.

Are you comparing like with like?

Hence my question. Are we? I recall that a 5/8 wave vertical was 'close' to
50 ohms at the feed point and could be 'adjusted' with an inductance across
the feed point (with the feedline at a tap perhaps?). That is the whole
point is using such a 'magic number' as 5/8 wavelength. If you look at the
impedance curves, though, you find that they are quite steep at this point,
so a small error in length causes a large error in impedance, and some
tuning will be needed. The 5/8 wave is not a 'build it and go' antenna!

Spend more time thinking about it.

I have, which is why I looked it up.


Is Kraus infallible? Could be he's wrong again.


=8o Oh no!!! Kraus wrong!?

Who's Kraus anyway? ;o)

Oh, I don't know. Just some guy that signed my Master's Thesis 16 years
ago.


----
Reg



--
Jim
N8EE

to email directly, send to my call sign at arrl dot net