Reg Edwards wrote:
And you are using the wrong formula for the resonant frequency of a
transnmission line anyway.

I once had a 2m Heathkit linear amplifier for my Wilson transceiver.
I chose the wrong length of coax between the two and when I ceased
to transmit, the amplifier would oscillate. My neighbor, also a ham,
told me I was transmitting a wandering signal that keyed all the 2m
repeaters in the area. That was back before PL was popular.
--
73, Cecil http://www.qsl.net/w5dxp



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On Sun, 1 Feb 2004 10:10:44 -0600, "John Smith"
wrote:
If you can explain my error, please do so rather than insulting me by saying
I am hopelessly mixed up.

Hi John,

You will undoubtedly find the answer when our resident troll argues
this from the other side of the argument in a future thread. Time and
conflict finds him everywhere eventually. ;-)

73's
Richard Clark, KB7QHC

"Reg Edwards" wrote in message
...
"John Smith" wrote -
Using a 1 meter length of RG58, it will resonate at f =
1/(2*pi*sqrt(L*C))
=
32.4 MHz.

============================
Obviously not. You're miles away from the right ball park.

And you are using the wrong formula for the resonant frequency of a
transnmission line anyway.



What is the formula you used to arrive at:

It will resonate as a 1/4-wave vertical at 3.5 MHz.

"Richard Clark" wrote in message
...
On Sun, 1 Feb 2004 10:10:44 -0600, "John Smith"
wrote:
If you can explain my error, please do so rather than insulting me by
saying
I am hopelessly mixed up.

Hi John,

You will undoubtedly find the answer when our resident troll argues
this from the other side of the argument in a future thread. Time and
conflict finds him everywhere eventually. ;-)

73's
Richard Clark, KB7QHC


Thanks, Richard. I didn't know the meaning of the word Troll until now. I
asked for an explanation but, well, you saw his answer:

"Obviously not. You're miles away from the right ball park.

And you are using the wrong formula for the resonant frequency of a
transnmission line anyway."

It seems to me that he could have at least let us in on his formula. If he
doesn't want to share knowledge with the group, and if he is not a troll,
why does he bother to post?

Oh, well. I guess the best thing is to ignore him.

John, KD5YI

On Sun, 1 Feb 2004 15:48:43 -0600, "John Smith"
wrote:


Thanks, Richard. I didn't know the meaning of the word Troll until now.

Well, actually you have been conned by the bait and switch.

I asked for an explanation but, well, you saw his answer:

"Obviously not. You're miles away from the right ball park.

And you are using the wrong formula for the resonant frequency of a
transnmission line anyway."

That is the troll. Reggie likes to rail against software - except his
own. He likes to rail against citing authorities - until he gushes on
about Lord Plushbottom. He absolute fulminates against passivity in
learning - and then offers software without divulging the concrete
fundamentals behind them. Then there are the side topics where he
regales how he is the only Brit to have lost WWII to the Americans.

It seems to me that he could have at least let us in on his formula. If he
doesn't want to share knowledge with the group, and if he is not a troll,
why does he bother to post?

About the only consistent advice you could expect are his reports of
the metaphysical clarity of view in looking through the bottom of a
wine bottle.

Oh, well. I guess the best thing is to ignore him.

And miss all this comedy? Residency comes from time and experience!
When Reggie showed up in this group, he was preceeded by one of his
countrymen from the UK amateur newsgroup begging our indulgence for
his advanced years and eccentric habits. Somehow there was the
breathlessness of "he's yours now" in that plea. ;-)

Anyway, taken over the average of his arguing both sides of an issue,
you will come away with something and unlike others who mince about,
Reggie can actually write code and offer results from first
principles.

73's
Richard Clark, KB7QHC

John Smith wrote,


Thanks, Richard. I didn't know the meaning of the word Troll until now. I
asked for an explanation but, well, you saw his answer:

"Obviously not. You're miles away from the right ball park.

And you are using the wrong formula for the resonant frequency of a
transnmission line anyway."

It seems to me that he could have at least let us in on his formula. If he
doesn't want to share knowledge with the group, and if he is not a troll,
why does he bother to post?

Oh, well. I guess the best thing is to ignore him.

John, KD5YI


Actually, some of Reg's stuff is close enough to be pretty good. He doesn't
like to give us any symbolic derivations, though. Maybe he's ashamed of them.
Anyway, like everyone else on this newsgroup, you can take him or leave him.
73,
Tom Donaly, KA6RUH
(PS You've just learned a valuable lesson about grouchy old Brits.)

"Tdonaly" wrote in message
...
John Smith wrote,


Thanks, Richard. I didn't know the meaning of the word Troll until now. I
asked for an explanation but, well, you saw his answer:

"Obviously not. You're miles away from the right ball park.

And you are using the wrong formula for the resonant frequency of a
transnmission line anyway."

It seems to me that he could have at least let us in on his formula. If
he
doesn't want to share knowledge with the group, and if he is not a troll,
why does he bother to post?

Oh, well. I guess the best thing is to ignore him.

John, KD5YI


Actually, some of Reg's stuff is close enough to be pretty good. He
doesn't
like to give us any symbolic derivations, though. Maybe he's ashamed of
them.
Anyway, like everyone else on this newsgroup, you can take him or leave
him.
73,
Tom Donaly, KA6RUH
(PS You've just learned a valuable lesson about grouchy old Brits.)



Thanks, Tom, and you, too, Richard. I appreciate the heads-up.

John, KD5YI

Sorry John, I didn't realise you are a novice.

To answer your question about how to calculate the 1/4-wave resonant
frequency of a vertical antenna, use the following formula -

Fres = 75 / Height * Velocity Factor

As given in the simple example in my first posting, Height = 1.5 metres and
Velocity Factor = 0.0701

And so the resonant frequency calculates to Fres = 3.5 MHz.

If you are unfamiliar with "velocity factor" then I suggest you do a Google
on it.
---
Reg

Tdonaly wrote:
"---I don`t have any better idea than you do what the current
distribution in any individual coil is. I suppose it depends on its
environment and its physical description."

Kraus` story of his discovery of the axial mode helical antenna starts
on page 222 of "Antennas". Kraus was a new Ohio State University faculty
member in 1946 when a famous scientist told him a helix wouldn`t work as
an an antenna as he had already tried it with no success.

The expert`s statement challenged Kraus to try for himself, and the rest
is history.

The first coil he wound was one wavelength in circumference and had 7
turns.. Kraus was pleased with the sharp end-fire beam of
circularly-polarized energy from the open end of the coil. Kraus found
the helical beam antenna had a resistive input and a wide frequency
bandwidth.

At low frequencies, outgoing and reflected waves along the helix were
almost equal in magnitude but as frequency increased, current
distribution changed dramatically in the helix.

At a circumference of one wavelength, there were 3 regions. Near the
antenna input, current decayed exponentially. Near the open end of the
helix, there was a standing wave for a short distance. In the middle
region, there was a relatively uniform current (small VSWR) which
extended over most of the helix. Kraus gives the plots of the currents
along the helix in Figure 8 on page 224.

Certainly, Tdonaly is correct. Different coils have different current
distributions, but Kraus` contribution interests me.

Best regards, Richard Harrison, KB5WZI