do you now how to explain this so normal people can understand?
On May 6, 6:27 am, Cecil Moore wrote:
If a Texas Bugcatcher Coil could be turned into a
traveling wave device instead of a standing wave
device, the inherent phase shift through the coil
would become obvious. I used the Helix option in
EZNEC to generate a reasonably close model of a
75m Texas Bugcatcher coil and loaded it with a
resistance equal to the coil's characteristic impedance
which essentially eliminated the reflected current,
leaving the forward current intact and visible. All
of the data points on the following web page came from
EZNEC. All of the files are available for downloading.
Please take a look at:

http://www.w5dxp.com/current2.htm
--
73, Cecil http://www.w5dxp.com

On 10 May 2007 12:32:53 -0700, wrote:

do you now how to explain this so normal people can understand?

Ah! The triumph of hope over experience.

Sorry Herbert,

Your questions are just too hard for this crew. Stick with asking
about squiggly lines and they will flock to answer.

73's
Richard Clark, KB7QHC

wrote:
do you now how to explain this so normal people can understand?


If traveling waves are used to measure phase shift though the coil in
question reliable data is obtained on phase shift.

If standing waves are used, the data is flawed.

Well, you asked for simple now, didn't you?

Regards,
JS

On May 11, 7:44 am, John Smith I wrote:
wrote:
do you now how to explain this so normal people can understand?

If traveling waves are used to measure phase shift though the coil in
question reliable data is obtained on phase shift.

If standing waves are used, the data is flawed.

Well, you asked for simple now, didn't you?

Regards,
JS

no i didn'tt ask for simple. i asked for an explanation that could be
understood. So far i don't see any comparisons of what makes 'bad'
data bad, only reasons. everuyone has reasons. reliable? flawed?
is this like ~2db? how flawed is ~?

wrote:
do you now how to explain this so normal people can understand?

One more simple "fact."

Standing waves are really not "standing." They are "moving in place."
(well, oscillating, actually)

silly-grin
JS

facts don't make very good explanations.

On May 11, 7:50 am, John Smith I wrote:
wrote:
do you now how to explain this so normal people can understand?

One more simple "fact."

Standing waves are really not "standing." They are "moving in place."
(well, oscillating, actually)

silly-grin
JS

wrote:
facts don't make very good explanations.

I found Cecils' .ez files (the excel sheets require the microsoft
product which some may not have access to) were an excellent
"explanation" of what he proposes. However, some don't, through this
process of debate, analysis and argument we may even find a deeper
understanding. Makes you wonder if they bother to download the free
trial version of EZNEC and bother to look ...

As to the debate, analysis and "controversy" over his offerings, well,
that is what makes it all interesting, isn't it? Not being a guru makes
this new to me, poor gurus, must bore 'em to death :-(

A great mind once said, (probably paraphrased here) "Genius is one
percent inspiration and ninety-nine percent perspiration."

Regards,
JS

On Fri, 11 May 2007 19:56:27 -0700, John Smith I
wrote:

wrote:
facts don't make very good explanations.

I found Cecils' .ez files (the excel sheets require the microsoft
product which some may not have access to) were an excellent
"explanation" of what he proposes.

Talk about the gulf between perception and reality.

73's
Richard Clark, KB7QHC

John Smith I wrote:
Makes you wonder if they bother to download the free
trial version of EZNEC and bother to look ...

The bugcatcher coil in coil505.EZ has 234 segments.
The free demo version of EZNEC is limited to 20
segments. Thus, something like a 2-4 turn helix
is all the free demo version will support.
--
73, Cecil http://www.w5dxp.com

Herbert wrote:
"Do you know how to explain this so normal people can understand?"

I `m not a Guru, but I`ll try.

First, there was adispute about delay in an antenna loading coil. That
provoked attempts to measure the delay. Then the argument turned to the
measurement methods.

The antenna signal travels from the transmitter through the coil and
through the stinger until it reaches the tip where it is forced to
reverse course by the open circuit. All the signal which has not been
radiated or lost in waste enroute starts its journey back toward the
transmitter. This reflected energy from the antenna tip is of no help in
determining delay through the loading coil but the ripples it makes,
when it adds and subtracts from the waveform of the forward energy,
makes measurements difficult. Frequently a directional coupler is used
to measure the energy moving in one direction, while ignoring the energy
moving in the opposite direction, to get a meaningful measurement. Cecil
proposed a resistor matching the impedance at the tip of the antenna to
avoid a reflection. This also eliminates the troublesome ambiguity.

Testing is convincing, perhaps, but not really necessary as the delay
through a coil has been understood and quantified at least since Ampere
who died in 1836.

The ARRL Handbook, mine is from 1976, explains inductance on page 25:
"Since the induced emf opposes the emf of the source, it tends to
prevent the current from rising rapidly when the circuit is closed."

Delay is a well known function of inductors. In early times they were
often called "retard coils".

Best regards, Richard Harrison, KB5WZI