On May 15, 5:42 am, Cecil Moore wrote:
Jim Kelley wrote:
On May 14, 7:44 pm, Cecil Moore wrote:
In order to get a valid measurement of the delay
through a coil, the coil needs to be loaded with
its characteristic impedance to minimize the
reflected current.

What if a 3' long stainless steel whip is loading the coil?

That makes the antenna a standing wave antenna.

It makes it an antenna.

Standing wave current has a negligible phase shift in
the coil or in the whip and therefore cannot be
used to measure the delay through a loading coil.

The delay through the coil depends on inductance and capacitance.

To the best of my knowledge, all attempted phase
measurements reported on this newsgroup, on current
through a loading coil have been made using standing
wave current with its fixed phase. No useful coil
delay information can come from such measurements.

So your claim is that information about Bugcatcher coils with a load
resistor attached is more useful?

ac6xg

Jim Kelley wrote:
Cecil Moore wrote:
Jim Kelley wrote:
Cecil Moore wrote:
That makes the antenna a standing wave antenna.

It makes it an antenna.

Well, putting a load resistor on a coil is a lot like
a T2FD. :-) In fact, the way that a T2FD lowers the
50 ohm SWR is by reducing the reflections from that
load resistor.

Standing wave current has a negligible phase shift in
the coil or in the whip and therefore cannot be
used to measure the delay through a loading coil.

The delay through the coil depends on inductance and capacitance.

Yes, but the delay is not measurable using standing
wave current because standing wave current doesn't
change phase in a coil or in a wire. So far, all of
the phase measurements reported here have been using
standing wave current phase. Standing wave current
essentially doesn't change phase in a 1/4WL long
open-ended antenna.

To the best of my knowledge, all attempted phase
measurements reported on this newsgroup, on current
through a loading coil have been made using standing
wave current with its fixed phase. No useful coil
delay information can come from such measurements.

So your claim is that information about Bugcatcher coils with a load
resistor attached is more useful?

It is more useful for determining the delay through the
coil. If you were trying to measure the phase shift
through a 1/4WL stub, would you use the standing wave
current with its zero phase shift? Or would you terminate
the stub in its characteristic impedance and measure
the phase shift in the subsequent traveling wave?

Here are some recently generated graphics around which
I am going to put some words. Hopefully, they will
provide some stand alone information.

Given: http://www.w5dxp.com/openstus.GIF

How would you determine the phase shift at any point
in the open stub?

Given: http://www.w5dxp.com/openstus.GIF

How would you determine the phase shift at any point
in the terminated stub?

Note that the two stubs are identical except for one
being open and one being terminated so they have
identical traveling-wave phase shifts.
--
73, Cecil http://www.w5dxp.com

I made a posting with a mistake, canceled it, and
am reposting. If the earlier posting got through,
please ignore it.

Jim Kelley wrote:
Cecil Moore wrote:
Jim Kelley wrote:
Cecil Moore wrote:
That makes the antenna a standing wave antenna.

It makes it an antenna.

Well, putting a load resistor on a coil is a lot like
a T2FD. :-) In fact, the way that a T2FD lowers the
50 ohm SWR is by reducing the reflections from that
load resistor.

Standing wave current has a negligible phase shift in
the coil or in the whip and therefore cannot be
used to measure the delay through a loading coil.

The delay through the coil depends on inductance and capacitance.

Yes, but the delay is not measurable using standing
wave current because standing wave current doesn't
change phase in a coil or in a wire. So far, all of
the phase measurements reported here have been using
standing wave current phase. Standing wave current
essentially doesn't change phase in a 1/4WL long
open-ended antenna.

To the best of my knowledge, all attempted phase
measurements reported on this newsgroup, on current
through a loading coil have been made using standing
wave current with its fixed phase. No useful coil
delay information can come from such measurements.

So your claim is that information about Bugcatcher coils with a load
resistor attached is more useful?

It is more useful for determining the delay through the
coil. If you were trying to measure the phase shift
through a 1/4WL stub, would you use the standing wave
current with its zero phase shift? Or would you terminate
the stub in its characteristic impedance and measure
the phase shift in the subsequent traveling wave?

Here are some recently generated graphics around which
I am going to put some words. Hopefully, they will
provide some stand alone information.

Given: http://www.w5dxp.com/openstus.GIF

How would you determine the phase shift at any point
in the open stub?

Given: http://www.w5dxp.com/termstus.GIF

How would you determine the phase shift at any point
in the terminated stub?

Note that the two stubs are identical except for one
being open and one being terminated so they have
identical traveling-wave phase shifts.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
The delay through the coil depends on inductance and capacitance.

Yes, but the delay is not measurable using standing
wave current because standing wave current doesn't
change phase in a coil or in a wire.

But you aren't measuring it. The point is, it's calculable.

So your claim is that information about Bugcatcher coils with a load
resistor attached is more useful?

It is more useful for determining the delay through the
coil.

The fact that it doesn't give you an answer that agrees with any other
method notwithstanding.

If you were trying to measure the phase shift
through a 1/4WL stub, would you use the standing wave
current with its zero phase shift?

If I were trying to measure delay I would use pulses.

Or would you terminate
the stub in its characteristic impedance and measure
the phase shift in the subsequent traveling wave?

I would want the system to be configured in exactly the same way as I
intended for it to be used.

Given: http://www.w5dxp.com/openstus.GIF

How would you determine the phase shift at any point
in the open stub?

Given: http://www.w5dxp.com/termstus.GIF

How would you determine the phase shift at any point
in the terminated stub?

The phase shift of what, with respect to what?

ac6xg

Jim Kelley wrote:
Cecil Moore wrote:
Yes, but the delay is not measurable using standing
wave current because standing wave current doesn't
change phase in a coil or in a wire.

But you aren't measuring it. The point is, it's calculable.

But w8ji and w7el *are* measuring it and getting something
different from those calculations. They are reporting their
flawed measurements as technical fact. That's what the
whole argument is about. There is no way in heck to get a
3 nS delay out of a 100 turn, 10", 2" diameter coil.

It is more useful for determining the delay through the
coil.

The fact that it doesn't give you an answer that agrees with any other
method notwithstanding.

It means that the existing posted methods are invalid. And
that doesn't extend just to the side that asserts the
delay through the coil is close to zero. It also extends
to the other side who accepts the use of standing-wave
current as a valid measurement technique. *All* of the
measurements made using standing-wave current are bogus.

If I were trying to measure delay I would use pulses.

How do you know the pulsed delay is the same as the
steady-state delay? Has anyone published a delay using
pulses? I'm not saying a pulsed delay won't yield valid
results - I just don't know. If it is a DC pulse, there
would be known problems.

I would want the system to be configured in exactly the same way as I
intended for it to be used.

Then you will find it is impossible to measure the delay
through the coil during steady-state.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Jim Kelley wrote:
But you aren't measuring it. The point is, it's calculable.

But w8ji and w7el *are* measuring it and getting something
different from those calculations. They are reporting their
flawed measurements as technical fact. That's what the
whole argument is about.

Only because you keep dragging them into it. I'm perfectly happy just
comparing your results with the results I get from Reg's program.

There is no way in heck to get a
3 nS delay out of a 100 turn, 10", 2" diameter coil.

There is something odd about Tom's printout. It's not clear to me
exactly what the instrument is actually displaying.

The fact that it doesn't give you an answer that agrees with any other
method notwithstanding.


It means that the existing posted methods are invalid.

:-) There exists no other possibility, naturally. I believe they call
these delusions of grandeur.

If I were trying to measure delay I would use pulses.


How do you know the pulsed delay is the same as the
steady-state delay?

In the same way, and to the same degree that I know the delay will be
the same tomorrow as it is today.

Has anyone published a delay using
pulses?

Delays are typically measured using pulses.

If it is a DC pulse, there
would be known problems.

Oh, I would never use those. :-)

I would want the system to be configured in exactly the same way as I
intended for it to be used.


Then you will find it is impossible to measure the delay
through the coil during steady-state.

If I thought that was true, I wouldn't have said what I did.

ac6xg

Cecil, W5DXP wrote:
"There is no way in heck to get 3 nanoseconds delay out of a 100 turn,
10-in., 2-in dia. coil."

I calculate 628 in. of wire divided by c (@ 1181.1x10 to the sixth power
in./sec.) = 0.53x10 to the minus 6 power, delay through the coil. That`s
just over 1/2 microsecond delay in the coil. A lot slower than Tom`s
coil but my signal sticks to the wire.

Best regards, Richard Harrison, KB5WZI

Jim Kelley wrote:
Delays are typically measured using pulses.

Please describe the pulse you intend to use on a
1/4WL long standing-wave antenna.

If I thought that was true, I wouldn't have said what I did.

If the delay through the loading coil in a standing-
wave antenna could be measured in situ, then there
would not be any argument. But maybe I am missing
something. How would you propose to measure the delay
through a loading coil during steady-state for a
standing-wave antenna?
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

Please describe the pulse you intend to use on a
1/4WL long standing-wave antenna.

Kind of a wispy brunette one, about 5'7". What difference would it
make, Cecil? One that is short compared to the delay.

If the delay through the loading coil in a standing-
wave antenna could be measured in situ, then there
would not be any argument. But maybe I am missing
something. How would you propose to measure the delay
through a loading coil during steady-state for a
standing-wave antenna?

When you post a question in that way I gotta wonder what you must
think is going on inside an antenna. What's different about the
'situ' during steady state that causes electromagnetic fields to
propagate differently than at other times?

73, ac6xg