Phase Shift through a 75m Texas Bugcatcher Coil
 

Uim, AC6XG wrote:
"Perhaps it should be noted that electromagnetic waves and photons
travel neither faster nor slower than the speed of light in their medium
of travel."

Yes. Corpuscles and waves have the same velocity given the same medium.

Best regards, Richard Harrison, KB5WZI

Phase Shift through a 75m Texas Bugcatcher Coil
 

Richard Harrison wrote:

"Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."

Well done, sir.

Kraus details this in his
section on helical antennas.

Fig. 7-19 is certainly interesting.

Cecil owes you a fruit basket I think. ;-)

73, Jim AC6XG

Phase Shift through a 75m Texas Bugcatcher Coil
 

Cecil Moore wrote:

What really gets my dander up are the gurus who use their
respected guru status to mount ad hominem attacks against
someone who they know is technically correct. In my book,
that is unethical behavior.

Cecil:

Which definition of Guru comes closest to your implied meaning:
(BTW, I think your use of "guru" is well justified)

# (Literally the word guru means teacher) Second level of its meaning is
that the guru is a spiritual leader, a saint, a Enlightener. GU
(darkness) RU (light); One who brings light into darkness. A teacher..
However, the meaning of the word Guru in Sikh terminology is at a
further higher level, and it stands for the 'prophet'.
www.sikhlink.com/sikh/terms.htm

# ("he who is heavy, weighty"): a spiritual teacher; cf. acarya
www.yogajournal.com/newtoyoga/159.cfm

# a religious percept or teacher, often the person from whom one
receives initiation or consecration.
www.trimondi.de/SDLE/Glossary.htm

# Literally teacher refers to one of the ten Sikh prophets, the Sikh
scripture (Guru Granth Sahib), or God.
www.sikhstudy.com/A7terms.html

# In general terms, a computer expert. UNIX experts are typically
referred to as gurus in polite company.
teladesign.com/ma-thesis/glossary.html

# a teacher who has attained mastery in the Supracosmic Sphere.
www.mudrashram.com/glossarypage.html

# "Remover of darkness;" guide. A teacher. Though it can connote a
teacher of any subject, guru usually denotes a spiritual teacher or master.

Phase Shift through a 75m Texas Bugcatcher Coil
 

Richard Harrison wrote:
Gene, W4SZ wrote:
"The current lags voltage principle does not settle anything in this
case."

W8JI claims that current flows into a turn at a coil end/s and is
induced without delay into all turns of the coil, overcoming delay that
the coil might otherwise impose.

If that were true, Terman would have told us so. In fact, Terman tells
us the opposite is true in explaning the traveling wave tube begining on
page 678 of his 1955 opus:

"The signal to be amplified is applied to the end of the helix adjacent
to the electron gun. Under appropriate operating conditions an amplified
signal then appears at the other end of the helix.-------inapplicable
info deleted-----. The applied signal propagates around the turns of the
helix and produces an electric field that is directed along the helix
axis. Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."

In other words, the axial advance is much like that of a threaded bolt
as the pitch angle is always fractional. Kraus details this in his
section on helical antennas.

Best regards, Richard Harrison, KB5WZI


Richard,

I would never argue with Terman.

You completely changed the subject, so I have nothing further to say.
The line you quoted above is still correct. Feel free to continue on in
whatever new direction you want.

73,
Gene
W4SZ

Phase Shift through a 75m Texas Bugcatcher Coil
 

Jim Kelley wrote:
Perhaps it should be noted that electromagnetic waves and photons travel
neither faster nor slower than the speed of light in their medium of
travel.

Obviously true for traveling waves. But how about the
"electromagnetic waves and photons" involved in standing
waves? Some folk here would have us believe that they are
not moving at all.
--
73, Cecil http://www.w5dxp.com

Phase Shift through a 75m Texas Bugcatcher Coil
 

Jim Kelley wrote:
Tom doesn't even have a dog in this fight as far as I know.

Tom's web page is in this dog fight. Tom has posted hundreds
of postings in the past in support of his instantaneous
current with no phase shift through a loading coil. He
even "measured" the phase shift through a large coil at
5 nS. Of course, his "measurement" was made with standing-
wave current which doesn't change phase.
--
73, Cecil http://www.w5dxp.com

Phase Shift through a 75m Texas Bugcatcher Coil
 

Jim Kelley wrote:
Richard Harrison wrote:
"Since the velocity with which the signal propagates along the
helix wire approximates the velocity of light if the frequency is not
too low (caveat is unimportant, see footnote in book), the axial field
due to the signal advances with a velocity that is very closely the
velocity of light multiplied by the ratio of helix pitch to helix
circumference."

Fig. 7-19 is certainly interesting.

Cecil owes you a fruit basket I think. ;-)

Unfortunately, I must disagree (very slightly) with Kraus.
Using Kraus' concepts *verbatim*, the delay through a coil
would be the same whether the wire is coiled up or straightened
out (if I understand correctly what he is saying).

On my web page at w5dxp.com/current2.htm I have a 30 turn
coil with a diameter of 6" causing a 38 degree phase shift
at 3.8 MHz. If the coil were straightened out, it would be
about pi*6"*30 = 565 inches or 47 feet. Since a wavelength
is about 259 feet at that frequency, 47 feet would be about
65 degrees. So Kraus' rule-of-thumb is off by about 70%.
His VF would be about 0.009 where the actual VF is more
like 0.106. 65 degrees of wire doesn't replace 65 degrees
of antenna. In this case, 65 degrees of wire replaces
38 degrees of antenna. The "missing degrees" are in the
impedance discontinuity between the coil and stinger.

There is an interaction between turns that increases the
VF of the coil so there is a very tiny grain of truth in
what Tom says. The interaction between turns increases the
coil VF from Kraus' 0.009 to the actual value of 0.016
but certainly not all the way to 1.0 as W8JI asserts.

Kraus may have been off by 70% but W8JI is off by 6000%
so it seems that Kraus was still a lot closer to the
technical truth that W8JI ever was.
--
73, Cecil http://www.w5dxp.com

Phase Shift through a 75m Texas Bugcatcher Coil
 

John Smith I wrote:
Which definition of Guru comes closest to your implied meaning:
(BTW, I think your use of "guru" is well justified)

Sorta using my own definition for "guru" here, John.
It is an individual who refuses to listen to anything
that mere mortals have to say and either already knows
everything or gets any new information from God Almighty
himself. Anything that I cannot tell from a religion is
being asserted by a "guru". A perfect example is the
assertion by W8JI that current travels the length of
a 75m Texas Bugcatcher coil instantaneously.

If that were true, Intel could speed up its computer
buses by adding a 75m Texas Bugcatcher coil to each
data/control line, i.e. it is a ridiculous assertion.
--
73, Cecil http://www.w5dxp.com

Phase Shift through a 75m Texas Bugcatcher Coil
 

Cecil Moore wrote:
Jim Kelley wrote:

Perhaps it should be noted that electromagnetic waves and photons
travel neither faster nor slower than the speed of light in their
medium of travel.


Obviously true for traveling waves. But how about the
"electromagnetic waves and photons" involved in standing
waves?

The only kind of electromagnetic waves I know about are the traveling
kind. Sorry I can't be more help.

73, ac6xg

Phase Shift through a 75m Texas Bugcatcher Coil
 

Cecil Moore wrote:

Jim Kelley wrote:

Tom doesn't even have a dog in this fight as far as I know.


Tom has posted hundreds
of postings in the past in support of his instantaneous
current with no phase shift through a loading coil.

Tom hasn't posted a single word to this thread that I am aware of.
The point is if you don't like what he says, you should take it up
with him. Know what I mean?

ac6xg