On May 9, 4:28 pm, Cecil Moore wrote:
Jim Kelley wrote:
The entire point of Richard's citation is that VF is a function of pitch
to circumference ratio. It explains the very thing that you need to
support your argument about phase delay across a coil.

Does "circumference" mean the circumference of the coil or
is it the actual wire length once around the helix?
--
73, Cecil http://www.w5dxp.com

2*Pi*radius

ac6xg

Jim Kelley wrote:
2*Pi*radius

Sorry, I'm a little handicapped since I have never seen
"Figure 7-19" and it has been removed from the web site.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

Jim Kelley wrote:

2*Pi*radius


Sorry, I'm a little handicapped since I have never seen
"Figure 7-19" and it has been removed from the web site.

I have the file. It's 7.5 megabytes. Do you have a broadband connection?

73 jk

Jim Kelley wrote:

Cecil Moore wrote:
Sorry, I'm a little handicapped since I have never seen
"Figure 7-19" and it has been removed from the web site.

I have the file. It's 7.5 megabytes. Do you have a broadband connection?

Yes, I have DSL but I also have the 3rd edition of "Antennas".
I think "Figure 8-32: Relative phase velocity p for different
pitch angles as a function of the helix circumference, C(lamda),
for the condition of in-phase fields in the axial direction",
is probably the same graph as Figure 7-19 in the 1st edition.
I'm assuming that the "relative phase velocity" is the same
thing as the VF of the coil.
--
73, Cecil, w5dxp.com

Cecil, W5DXP wrote:
"I`m assuming that the "relative phase velocity" is the same thing as
the VF of the coil."

Back a couple of pages on 251, Kraus defines v/c as equal to "relative
phase velocity of the wave propagating along the helical conductor, v
being the phase velocity along the helical conductor and c being the
velocity of light in free space."

Repetition of "along the helical conductor" implies to me, thal like
Terman, Kraus says the signal follows the actual wire, not sprinting
across the coil as if it were a straight rod.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
Repetition of "along the helical conductor" implies to me, thal like
Terman, Kraus says the signal follows the actual wire, not sprinting
across the coil as if it were a straight rod.

Yes, I believe you are right about that.
--
73, Cecil, w5dxp.com

Richard Harrison wrote:

Repetition of "along the helical conductor" implies to me, thal like
Terman, Kraus says the signal follows the actual wire, not sprinting
across the coil as if it were a straight rod.

It seems to me there is more than just one way to use a wire to convey
a signal. In fact it can be difficult to prevent a wire from using
more than just one, especially when there are other wires nearby.

73, Jim AC6XG

Jim Kelley wrote:
It seems to me there is more than just one way to use a wire to convey a
signal. In fact it can be difficult to prevent a wire from using more
than just one, especially when there are other wires nearby.

Yep, I'm afraid that Kraus was wrong to a certain degree.
Of course, he didn't have NEC in 1950. If we double Kraus'
calculated relative phase velocity for loading coils, we
will be closer to the results predicted by EZNEC.
--
73, Cecil http://www.w5dxp.com