Loading Coils; was : Vincent antenna
 

Jim Kelley wrote:
In the face of such a redoubtable accusation I'm somewhat reluctant to
admit my view that a phase shift across a coil of this sort would in
fact be directly proportional to any propagation delay through that coil.

That's certainly true for traveling-wave current.
Definitely not true for standing-wave current which
doesn't change phase. I don't know that the comprehension
problem is here - maybe this graph will help.

http://www.w5dxp.com/travstnd.gif
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
Gene Fuller wrote:
Cecil Moore wrote:

Take I = K1*cos(x)*cos(wt), a standing-wave equation.
Let t be any fixed value. cos(x) is an amplitude value
and does NOT vary with time. Therefore, the phase of the
standing-wave signal is constant at any particular time
and does NOT depend upon position along the wire or coil.

Now take I = K2*cos(x+wt), a traveling-wave equation.
Let t be any fixed value. The length dimension 'x'
has an effect on phase, i.e. the phase of of the
signal indeed does depend upon BOTH position AND time.


Cecil,

I know what you are trying to say, but you got the message screwed up.
If 't' is fixed, then the equations are essentially the same with
regard to 'x'. That is typical; a snapshot in time does not say much
about the wave behavior.

73,
Gene
W4SZ

It's generally cos(kx), but maybe Cecil is using a wave where k = 1,
that is, the wavelength is 2*Pi.
73,
Tom Donaly, KA6RUH

Tom,

Sure, that too.

I think one of the reasons this subject keeps coming back again, and not
only from Cecil, is that phase is deceptively simple and very easy to
misuse. A year or so ago I counted up at least 5 or 6 different meanings
of "phase" in routine use on RRAA. Lewis Carroll would feel right at
home here.

73,
Gene
W4SZ

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:
Cecil Moore wrote:

I also measured ~12-13 ns delay
through 50 turns of the same coil stock that Tom
was using when he measured a 3 ns delay through
a 100 turn coil. That 12-13 ns delay is within
15% of the Corum equation predictions.

Using what equipment? And with what load?

Equipment was a dual-trace 100 MHz O'Scope. If I
remember correctly, the load was four 600 ohm non-
inductive resistors in series. My notes are in a
box somewhere.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
However, there is phase
information on a standing wave, and you know it.

Do you disagree with what Gene Fuller had to say?
The phase information is there all right but it is not in
the phase of the standing-wave - it is in the amplitude.
And W8JI did not use the amplitude to measure the phase.
Perhaps the following graph will help you to comprehend
this subject.

http://www.w5dxp.com/travstnd.gif
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Gene Fuller wrote:
Cecil Moore wrote:
Here's what Gene Fuller had to say about this subject:

There you go again; quoting a questionable source.

:-)
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Tom Donaly wrote:
However, there is phase
information on a standing wave, and you know it.

Do you disagree with what Gene Fuller had to say?
The phase information is there all right but it is not in
the phase of the standing-wave - it is in the amplitude.
And W8JI did not use the amplitude to measure the phase.
Perhaps the following graph will help you to comprehend
this subject.

http://www.w5dxp.com/travstnd.gif

Cecil,

That graph page is beyond simple amusement; it is hilarious.

73,
Gene
W4SZ

Loading Coils; was : Vincent antenna
 

Tom Donaly wrote:
It's generally cos(kx), but maybe Cecil is using a wave where k = 1,
that is, the wavelength is 2*Pi.

In the equations I posted, x is in degrees. It is (kx)
in the following graph:

http://www.w5dxp.com/travstnd.gif
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Gene Fuller wrote:
That graph page is beyond simple amusement; it is hilarious.

It was graphed from data generated by EZNEC and
agrees with what you said in an earlier posting,
that there is no phase information in the phase
of the standing-wave.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

On Tue, 04 Dec 2007 21:59:04 -0600, Cecil Moore
wrote:

Equipment was a dual-trace 100 MHz O'Scope. If I
What make, model?

Loading Coils; was : Vincent antenna
 

AI4QJ wrote:

Excellent information. The current along the coil reduces as it "replaces" a
section of an equivalent straight antenna section in degrees. This is true
even to the extent as existing current distribution in the section where the
coil is placed. I can see how someone in the 1950's might assume that
current in = current out (kirchoff) and not consider the degrees electrical
length occupied by the coil but ARRL should not be propagating such
information today. We know better now and besides, it is plain and simple
"intuitive" once you know that current changes along the electrical "degree
length" in an unloaded antenna, the same should happen in the degree length
loaded coil.

Thanks for taking the time to show the root of the controversy.

Also, as indicated, the pictures do say 1000 words and it also looks like
W8JI ended up agreeing with you after you pointed out the same effect at
"ON4UN's Low Band DXing", 3rd Edition, on page 9-34.

It's unfortunate that your intuition is wrong -- an inductor doesn't
"replace" part of an antenna.

If you'd like to learn a lot more about this, and the history of the
discussion, see my posting in this group on April 6, 2006 under the
topic " Current across the antenna loading coil - from scratch". It
includes some references to careful measurements I made more than a year
previous which showed that the simplified view of "replacement" is
flawed. If you have the stomach for it, look at the thread which
included the measurement postings, and see how well Cecil and Yuri were
able to do in applying their theory to predict the phase shift across a
simple, small toroidal inductor.

You can find archives of previous postings at http://groups.google.com.

Roy Lewallen, W7EL

Loading Coils; was : Vincent antenna
 

On Tue, 4 Dec 2007 23:48:31 -0500, "AI4QJ" wrote:

I can see how someone in the 1950's might assume that
current in = current out (kirchoff) ... We know better now

Hi Dan,

This is called the "fallacy of present mindedness."

Kirchoff demands that analysis be done free of network geometries that
are wavelength dependant. This was known long before the 1950s.

And another issue:
current in = current out
is not a Kirchoff law for a component and the currents on its leads
(this is a tempting sophomore lab shortcut that is strictly lumped
circuit stuff - which absolutely demands 0 wavelength). Kirchoff's
first law is for a point, or junction; and, of course, there is no
potential across a point or junction (as there would be for a
component).

Engineers knew this long before 1950, presumably 100+ years before in
1845. The first Telegrapher's equations (125 years ago or more) had
to overcome wavelength restrictions - hence the work of Heaviside
through Maxwell.

This, of course, is a repetition for your sake which has been offered
in years past to the same "debaters" for whom it has had:
1. absolutely no impact to their passion play;
2. been entirely forgotten;
3. been wholly outside of their researching skills (i.e. never having
ever taken a circuits lab course beyond the sophomore first quarter);
4. been a combination of 1, 3, and 4 with the pretense of 2.

With the pretense of 2, we will be visited by this astonishing
revelation of current change through the coil again in the future, as
we have been on successive occasions throughout the past. There will
be new and remarkable papers culled from the net that exhibit math to
prove all cogent points - except to sweep the wavelength restriction
for Kirchoff under the rug again.

Thus was it ever, thus will it be again....

73's
Richard Clark, KB7QHC

Loading Coils; was : Vincent antenna
 

AI4QJ wrote:

Roy, I will definitely be going through those archives. However, we have
seen many antennas in which the entire antenna is wound as a spiral with a
relatively large pitch in order to shorten it. In this case, the entire
antenna could also be considered an "inductor". For that matter, even a
straight length of antenna wire could be considered a 1/2 turn "inductor".
Ignoring the latter extreme example for now, could not the common spirally
wound antenna be considered an inductor that "replaces" the entire antenna?
I'm not saying it is a "good" antenna but it could be 90 degrees long and
have the same distribution of standing wave current as a straight antenna.
Also, I wonder if we are arguing semantics over the definition of
"inductor".

Definition is definitely a part of the problem. I don't have so much
trouble with variations of defining an "inductor" as I do with the
concept of "replacing" part of an antenna or measuring an inductor in
"electrical degrees". A straight wire and a coiled wire both have the
property of inductance, but in general a coiled wire will radiate less
than a straight one of the same inductance. The coupling to ground or
the other half of the antenna is also different for straight and coiled
wires. So one doesn't directly "replace" the other. The concept of
"replacement" is overly simplistic and, when extrapolated, can lead to
erroneous conclusions (or in the case of Cecil's and Yuri's theories,
multiple and contradictory conclusions).

Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and
explain where the missing degrees went.

Roy Lewallen, W7EL

Loading Coils; was : Vincent antenna
 

AI4QJ wrote:
... it is plain and simple
"intuitive" once you know that current changes along the electrical "degree
length" in an unloaded antenna, the same should happen in the degree length
loaded coil.

Unfortunately, both sides cannot be right but both sides
are still illustrated as fact in the ARRL Antenna Book.
There's one graphic that shows the drop in amplitude
through a loading coil and another that shows no change.
Apparently, the ARRL doesn't know what happens so they
show both possibilities as technically correct.

Also, as indicated, the pictures do say 1000 words and it also looks like
W8JI ended up agreeing with you after you pointed out the same effect at
"ON4UN's Low Band DXing", 3rd Edition, on page 9-34.

Unfortunately, it is rumored that W8JI has talked ON4UN
into changing that in the latest edition. I emailed ON4UN
about it but got no reply.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:
Cecil Moore wrote:
Equipment was a dual-trace 100 MHz O'Scope.

What make, model?

Leader LBO-518
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:
It's unfortunate that your intuition is wrong -- an inductor doesn't
"replace" part of an antenna.

Roy, you will not understand how an inductor replaces part
of an antenna until you perform the simple stub exercise
that I have provided. Assume ideal lossless conditions and
a VF=1.0.

--600 ohm line---+---10 deg 100 ohm line---open

How many degrees of 600 ohm line does it take to result
in a stub that looks like it is 1/4 wavelength, i.e.
electrically 90 degrees long.

Anyone want to take bets on who will perform this simple
exercise and who will refuse to touch it with a ten foot
pole?

If you'd like to learn a lot more about this, and the history of the
discussion, see my posting in this group on April 6, 2006 under the
topic " Current across the antenna loading coil - from scratch". It
includes some references to careful measurements I made more than a year
previous which showed that the simplified view of "replacement" is
flawed.

Note to AI4QJ:
Roy's conclusion was obviously flawed because standing-wave
current was used for his measurement. When I pointed out Roy's
error using EZNEC, he buried his head in the sand by ploinking
me. After all these years, no rational person can believe that
a coil doesn't replace part of a mobile antenna.

However, the side that believes that a coil replaces all of
the missing antenna degrees is also wrong. There is a third
phase shift at the coil to stinger junction that this side
is missing.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:
The concept of
"replacement" is overly simplistic and, when extrapolated, can lead to
erroneous conclusions (or in the case of Cecil's and Yuri's theories,
multiple and contradictory conclusions).

Roy continues with his Big Lie. There are no contradictions.
Perform the following simple stub example assuming lossless
conditions and VF=1.0.

---600 ohm line---+---10 deg 100 ohm line---open

How many degrees of 600 ohm line does it take to make the
stub electrically 1/4WL (90 deg) long? Why doesn't it take
80 degrees of 600 ohm line? Where are the missing degrees?

Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and
explain where the missing degrees went.

If you would just look at my simple stub example, you would
understand where those missing degrees are. They are at the
coil to stinger junction and may represent more than half
the degrees in the antenna. The coil represents a good portion
of the rest of the degrees. The stinger is usually about 11
degrees long.

Roy continues to defend his old wives' tale even in the
face of overwhelming evidence to the contrary.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:
Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and
explain where the missing degrees went.

I didn't fail to explain them, Roy, you just failed to listen
to reason, ploinked me, and started uttering Big Lies about
me.

In my 75m mobile base-loaded bugcatcher antenna:
1. The coil occupies ~25 degrees of antenna.
2. The impedance discontinuity at the coil to stinger
junction provides a ~44 degree phase shift.
3. The stinger occupies ~11 degrees of antenna.

At resonance the antenna is electrically
25+54+11 = 90 deg long even though it is physically
only ~12 degrees long.

All of the "missing degrees" appear at the impedance
discontinuities but you already know that since I
explained this to you two years ago.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Gene Fuller wrote:
Cecil Moore wrote:
http://www.w5dxp.com/travstnd.gif

That graph page is beyond simple amusement; it is hilarious.

I'm glad you find it amusing, Gene. Now please explain
why EZNEC came up with that data based on the EZNEC
files that you are free to download and analyze.

All I did was simulate a coil using the helix feature
in EZNEC. For standing-waves, I left the coil un-
terminated. For traveling-waves, I terminated the
coil in close to its characteristic impedance. The
graphs are the exact data reported by EZNEC so
W7EL can be blamed for the results, not I.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:


A straight wire and a coiled wire both have the property of inductance,

The rest snipped


(Hand smacking against my forehead) For this dilettante, that simple
statement causes a lot of things to fall into place and make sense.

Thanks much, Roy.

- 73 de Mike N3LI -

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

If you would just look at my simple stub example, you would
understand where those missing degrees are. They are at the
coil to stinger junction and may represent more than half
the degrees in the antenna. The coil represents a good portion
of the rest of the degrees. The stinger is usually about 11
degrees long.

I don't understand. At the junction between the two?

Does this mean that an extremely short antenna could be built that
consisted of several small coils, and lots of junctions?

typical bad ascii art:

| - top stinger
|
/ - coil and junction
/
|
/ - coil and junction
/
|
/ - coil and junction
/
|
| - bottom of antenna



- 73 de Mike N3LI -

Loading Coils; was : Vincent antenna
 

Michael Coslo wrote:
Cecil Moore wrote:
If you would just look at my simple stub example, you would
understand where those missing degrees are. They are at the
coil to stinger junction and may represent more than half
the degrees in the antenna. The coil represents a good portion
of the rest of the degrees. The stinger is usually about 11
degrees long.

I don't understand. At the junction between the two?

The loading coil has a Z0 in the thousands of ohms, e.g.
about 4000 ohms for my 75m Texas Bugcatcher coil. The
stinger's Z0 is a few hundred ohms, e.g. 350 ohms. There
will be a phase shift at the 4000 ohm to 350 ohm junction.
It is a free, lossless phase shift from Mother Nature.

Does this mean that an extremely short antenna could be built that
consisted of several small coils, and lots of junctions?

No, you gain degrees at the high to low impedance junction.
You *lose degrees* at the low to high impedance junction.
That's why you need more coil for a center-loaded antenna
than you do for a base-loaded antenna.

And remember that the radiation efficiency depends upon
*physical* length, not electrical length.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

On 5 Dec, 06:29, Cecil Moore wrote:
Roy Lewallen wrote:
Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and
explain where the missing degrees went.

I didn't fail to explain them, Roy, you just failed to listen
to reason, ploinked me, and started uttering Big Lies about
me.

In my 75m mobile base-loaded bugcatcher antenna:
1. The coil occupies ~25 degrees of antenna.
2. The impedance discontinuity at the coil to stinger
junction provides a ~44 degree phase shift.
3. The stinger occupies ~11 degrees of antenna.

At resonance the antenna is electrically
25+54+11 = 90 deg long even though it is physically
only ~12 degrees long.

All of the "missing degrees" appear at the impedance
discontinuities but you already know that since I
explained this to you two years ago.
--
73, Cecil http://www.w5dxp.com


Gentleman.
An update on Gaussian antennas
Guffaws heard

Took apart my helix wound on a garbage can for 160M
which was 1.5 :1 form wound and decided to make it
in horizontal element form.
Wires were 28 feet in length and I wound them tightly on
a 2 inch plastic pipe with pairs of wires,
two wires up and two wires down.
Made three of these assemblies and let the insulated wire "spring"
so I could place them on a 20 foot plastic pipe ,again 2 inches
diameter
and then connected them up with wire nuts.
When near to the ground the resonant impedance was in the
hundreds and changed little in the hunt for a sweet spot.
When placed 70 feet up impedances went to pot so I made
another two assemblies and connected them to the antenna assy.
without changing the overal length. Impedance was less than 2:1
across the 160 metre band. This resonance point I would call a
std resonance, where as, the ground measured a anti resonance.
As you can see the antenna revolves arounda full wave and
thus does not require a ground plain and conforms with
my Gaussian definition for a radiator.( The radiator can be any
size ,shape or elevation as long as the material is diamagnetic
and in a state of equilibrium)
( This, by the way, can be seem as what Einstein was looking for
twenty years but without success)
As you can see proximity to ground upset the equilibrium,but when
raised
to 70 feet the length aproached the 7/4 WL and probably woulD have
finished up around there if I could raise it in excess of a 1/2WL.
Wire used was #18 insulated house wire.
The antenna has multi resonances with the resistive resonances
increasing in value until it was a maximum at 160 M.
Snow has arrived so I will stay with this form until spring
while working on it to make it an ALL FREQUENCY GAUSSIAN
DIRECTIVE ANTENNA.
Covered the element with plastic sheeting because freezing
rain would cling to the windings and make it heavy.


Got any opinions or comments that could add to my understanding
of my present antenna? Don't mind contraversy as any discussion
tends to shed light in unexpected corners.
Best regards
Art

Loading Coils; was : Vincent antenna
 

On Wed, 05 Dec 2007 07:44:11 -0600, Cecil Moore
wrote:

Richard Clark wrote:
Cecil Moore wrote:
Equipment was a dual-trace 100 MHz O'Scope.

What make, model?

Leader LBO-518
Using what probes?

Loading Coils; was : Vincent antenna
 

Richard Clark wrote:
Using what probes?

Toroidal current pickup coils designed by W7EL
with the standard voltage probes.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:
Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and explain
where the missing degrees went.


"Cecil Moore" wrote

If you would just look at my simple stub example, you would
understand where those missing degrees are. They are at the
coil to stinger junction and may represent more than half
the degrees in the antenna. The coil represents a good portion
of the rest of the degrees. The stinger is usually about 11
degrees long.
_______________

The coil provides whatever inductive reactance is needed to make the
RADIATOR (the stinger, and mounting stub for the coil+stinger, if used)
functionally non-reactive as a system, at its feedpoint.

An 11-degree radiator/stinger doesn't radiate the power that will flow into
it any differently whether the system is resonant or not. However a
resonant system supplies more of the available source power to the stinger,
so that it CAN be radiated.

The fact that adding a coil to an 11-degree radiator produced the system
reactance a 90-degree, unloaded, linear radiator does not mean that the coil
and its junction to the stinger have supplied the "missing electrical
degrees" to the antenna system. The RADIATOR is still only 11 degrees long,
and will have same radiation resistance and relative field pattern,
regardless of the coil. The coil only supplied a non-reactive condition at
the system feedpoint.

Note that unloaded, linear radiators also can be naturally resonant at
physical/electrical lengths greater than ~90 degrees. Does that make the
same coil that can load an 11-degree stinger to resonance also responsible
for those greater "missing degrees?"

The effort spent here in bitter argument about phase shift through a coil,
and missing degrees would be better spent on methods of improving the
radiation resistance of such systems, and reducing the matching and r-f
ground losses that limit their performance.

RF

Loading Coils; was : Vincent antenna
 

Cecil, W5DXP wrote:
"However, the side that believes that a coil replaces all of the missing
antenna degrees is wrong."

It certainly can!

I worked the summer of 1949 at the KPRC-KXYZ broadcasting plant at Deep
Water (Pasadena), Texas. An operator there, J.L. Davis, W5LIT, had a war
surplus ART-13 in the trunk of his new 1949 Ford which was powerd by a
PE-103 dynamotor, or something of the sort.

Antenna was a cane fishing pole wound from end to end with wire except
for some bare pole to bolt on his rear bumper.

It radiated very well without any stinger or mast. Its problem was high
Q. When J.L. Cranked up the modulation, he would at times light up the
atmosphere with ionization from the tip of his antenna.

I`ll give you another example of a larger diameter but much shorter coil
used as the sole antenna. It is the radial mode helix which has a
carefully selected diameter and pitch to cause radiatiation at right
angles to its axis. It is shown in Fig. 17-5 on page 407 of "The
Complete Broadcast Antenna Handbook" by John E. Cunningham. It was once
used by TV and FM stations. Horizontally polarized, its popularity has
waned.

Best regards, Richard Harrison, KB5WZI

Loading Coils; was : Vincent antenna
 

"Roy Lewallen" wrote in message
...
AI4QJ wrote:

Roy, I will definitely be going through those archives. However, we have
seen many antennas in which the entire antenna is wound as a spiral with
a relatively large pitch in order to shorten it. In this case, the entire
antenna could also be considered an "inductor". For that matter, even a
straight length of antenna wire could be considered a 1/2 turn
"inductor". Ignoring the latter extreme example for now, could not the
common spirally wound antenna be considered an inductor that "replaces"
the entire antenna? I'm not saying it is a "good" antenna but it could be
90 degrees long and have the same distribution of standing wave current
as a straight antenna. Also, I wonder if we are arguing semantics over
the definition of "inductor".

Definition is definitely a part of the problem. I don't have so much
trouble with variations of defining an "inductor" as I do with the concept
of "replacing" part of an antenna or measuring an inductor in "electrical
degrees". A straight wire and a coiled wire both have the property of
inductance, but in general a coiled wire will radiate less than a straight
one of the same inductance. The coupling to ground or the other half of
the antenna is also different for straight and coiled wires. So one
doesn't directly "replace" the other. The concept of "replacement" is
overly simplistic and, when extrapolated, can lead to erroneous
conclusions (or in the case of Cecil's and Yuri's theories, multiple and
contradictory conclusions).

Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and explain
where the missing degrees went.

Roy Lewallen, W7EL

Clouding the issue. "Lost" degrees were not the controversy.

The main argument was (W8JI, W7EL et al) that current along the loading coil
in the resonant quarter wave radiator is constant or very close to, while
(W9UCW, K3BU, W5DXP et al) found that it diminishes toward the stinger by as
much as 40 - 60 %. The rest was nitpicking and drive around the fact trying
to "prove" us wrong or inaccurate or making up "our" theories.

The replacement degrees idea was used to demonstrate the behavior or effect
of the loading coil on the current distribution along the coil and ANTENNA
which is reflective of performance/efficiency of the loaded radiator
(proportional to the area under the current curve distribution).

The "guru" crowd can't seem to swallow this and are harping on this or that,
while any turkey ham can see the effect by grabbing the loading coil and
feeling the heat, more at the bottom than at the top.

The rest of discussions led to better understanding of what is happening in
the loaded element and thanks to Cecil for digging into it and 'splaining
the possible effects.

Which brings me to another subject: standing wave vs. traveling wave
antennas, but that is another story which I would like to get deeper
understanding.

So the argument that missing degrees to fourth decimal point are not there
is just to mask the admission of being grossly wrong and admitting to it and
perhaps even giving some credit where it's due.

Glad that W8JI does not wear inquisitor mantle, or you would have fried by
now Cecil :-)

73 Yuri, K3BU.us

Loading Coils; was : Vincent antenna
 

On 4 Dec, 23:34, Roy Lewallen wrote:
AI4QJ wrote:

Roy, I will definitely be going through those archives. However, we have
seen many antennas in which the entire antenna is wound as a spiral with a
relatively large pitch in order to shorten it. In this case, the entire
antenna could also be considered an "inductor". For that matter, even a
straight length of antenna wire could be considered a 1/2 turn "inductor".
Ignoring the latter extreme example for now, could not the common spirally
wound antenna be considered an inductor that "replaces" the entire antenna?
I'm not saying it is a "good" antenna but it could be 90 degrees long and
have the same distribution of standing wave current as a straight antenna.
Also, I wonder if we are arguing semantics over the definition of
"inductor".

Definition is definitely a part of the problem. I don't have so much
trouble with variations of defining an "inductor" as I do with the
concept of "replacing" part of an antenna or measuring an inductor in
"electrical degrees". A straight wire and a coiled wire both have the
property of inductance, but in general a coiled wire will radiate less
than a straight one of the same inductance. The coupling to ground or
the other half of the antenna is also different for straight and coiled
wires. So one doesn't directly "replace" the other.

Where on earth did this little gem come from?
W8ti states a similar thing when he says a wire should be as straight
as possible . I suspect that some conditions and definitions are to
be added before such a generalized statement can be made.
Seems like the beginning of an old wives tale that can produce a
thread
by Cecil that could last a decade before it is finally snuffed out
unless the statement is securely bound by a definition where there
can be no misunderstanding especially by those well versed in
relatavistic sciences.Let's face it radiation can be generated
from a point source which can be seen as three dimensional where as
a straight wire is two dimensional
Art KB9MZ





The concept of
"replacement" is overly simplistic and, when extrapolated, can lead to
erroneous conclusions (or in the case of Cecil's and Yuri's theories,
multiple and contradictory conclusions).

Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and
explain where the missing degrees went.

Roy Lewallen, W7EL

Loading Coils; was : Vincent antenna
 

On 5 Dec, 07:49, (Richard Harrison) wrote:
Cecil, W5DXP wrote:

"However, the side that believes that a coil replaces all of the missing
antenna degrees is wrong."

It certainly can!

I worked the summer of 1949 at the KPRC-KXYZ broadcasting plant at Deep
Water (Pasadena), Texas. An operator there, J.L. Davis, W5LIT, had a war
surplus ART-13 in the trunk of his new 1949 Ford which was powerd by a
PE-103 dynamotor, or something of the sort.

Antenna was a cane fishing pole wound from end to end with wire except
for some bare pole to bolt on his rear bumper.

It radiated very well without any stinger or mast. Its problem was high
Q. When J.L. Cranked up the modulation, he would at times light up the
atmosphere with ionization from the tip of his antenna.

I`ll give you another example of a larger diameter but much shorter coil
used as the sole antenna. It is the radial mode helix which has a
carefully selected diameter and pitch to cause radiatiation at right
angles to its axis. It is shown in Fig. 17-5 on page 407 of "The
Complete Broadcast Antenna Handbook" by John E. Cunningham. It was once
used by TV and FM stations. Horizontally polarized, its popularity has
waned.

Best regards, Richard Harrison, KB5WZI

The resultant vector of all vectors involved with radiation can NEVER
be at right angles to the axis of a radiator. PERIOD
Art KB9MZ

Loading Coils; was : Vincent antenna
 

"art" wrote
The resultant vector of all vectors involved with radiation can
NEVER be at right angles to the axis of a radiator. PERIOD
___________

Are you thinking that your statement above applies to the radiation from the
vertical monopoles used by commercial AM broadcast stations ?

Their performance has been accurately and carefully measured going back 70+
years, and the "resultant vector" of their radiation at right angles to the
radiator axis certainly is not zero.

RF

Loading Coils; was : Vincent antenna
 

On 5 Dec, 07:32, art wrote:
On 5 Dec, 06:29, Cecil Moore wrote:





Roy Lewallen wrote:
Take a look at my 2005 measurements and see if you can do what Cecil and
Yuri failed to do coherently -- use the "replacement" concept and
explain where the missing degrees went.

I didn't fail to explain them, Roy, you just failed to listen
to reason, ploinked me, and started uttering Big Lies about
me.

In my 75m mobile base-loaded bugcatcher antenna:
1. The coil occupies ~25 degrees of antenna.
2. The impedance discontinuity at the coil to stinger
junction provides a ~44 degree phase shift.
3. The stinger occupies ~11 degrees of antenna.

At resonance the antenna is electrically
25+54+11 = 90 deg long even though it is physically
only ~12 degrees long.

All of the "missing degrees" appear at the impedance
discontinuities but you already know that since I
explained this to you two years ago.
--
73, Cecil http://www.w5dxp.com

Gentleman.
An update on Gaussian antennas
Guffaws heard

Took apart my helix wound on a garbage can for 160M
which was 1.5 :1 form wound and decided to make it
in horizontal element form.
Wires were 28 feet in length and I wound them tightly on
a 2 inch plastic pipe with pairs of wires,
two wires up and two wires down.
Made three of these assemblies and let the insulated wire "spring"
so I could place them on a 20 foot plastic pipe ,again 2 inches
diameter
and then connected them up with wire nuts.
When near to the ground the resonant impedance was in the
hundreds and changed little in the hunt for a sweet spot.
When placed 70 feet up impedances went to pot so I made
another two assemblies and connected them to the antenna assy.
without changing the overal length. Impedance was less than 2:1
across the 160 metre band. This resonance point I would call a
std resonance, where as, the ground measured a anti resonance.
As you can see the antenna revolves arounda full wave and
thus does not require a ground plain and conforms with
my Gaussian definition for a radiator.( The radiator can be any
size ,shape or elevation as long as the material is diamagnetic
and in a state of equilibrium)
( This, by the way, can be seem as what Einstein was looking for
twenty years but without success)
As you can see proximity to ground upset the equilibrium,but when
raised
to 70 feet the length aproached the 7/4 WL and probably woulD have
finished up around there if I could raise it in excess of a 1/2WL.
Wire used was #18 insulated house wire.
The antenna has multi resonances with the resistive resonances
increasing in value until it was a maximum at 160 M.
Snow has arrived so I will stay with this form until spring
while working on it to make it an ALL FREQUENCY GAUSSIAN
DIRECTIVE ANTENNA.
Covered the element with plastic sheeting because freezing
rain would cling to the windings and make it heavy.

Got any opinions or comments that could add to my understanding
of my present antenna? Don't mind contraversy as any discussion
tends to shed light in unexpected corners.
Best regards
Art- Hide quoted text -

- Show quoted text -

Whooops
I made an error. The original construction was four(4) units of
windings, not three(3). Each assembly consisted of eight (8)
wires of insulated #18 wire of a length of twenty eight (28)
feet which gave a anti resonance at 160 M.
Two (2)more assemblies were added to get a std resonance at
seventy (70) feet. Note each length of windings is free to
move laterally without entanglement because of contra winding,
tho winding helix angles change somewhat relative to each other .
Thus gain will be a few percent less than optimum.
Sorry to have mislead you if you are comparing coil lengths
and wire lengths.
Best regards
Art Unwin KB9MZ...xg (uk)
Now out in the snow to find the wires for the rotator as they
go underground and connect them together.

Loading Coils; was : Vincent antenna
 

On 5 Dec, 09:01, "Richard Fry" wrote:
"art" wrote The resultant vector of all vectors involved with radiation can
NEVER be at right angles to the axis of a radiator. PERIOD

___________

Are you thinking that your statement above applies to the radiation from the
vertical monopoles used by commercial AM broadcast stations ?

Their performance has been accurately and carefully measured going back 70+
years, and the "resultant vector" of their radiation at right angles to the
radiator axis certainly is not zero.

RF

So you are back again. Read the posting several times from now on.
I NEVER SAID ANYTHING ABOUT ZERO RADIATION!
I am close to plonking you because of your twisted reading
just wastes my time.

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Gene Fuller wrote:
Cecil Moore wrote:
http://www.w5dxp.com/travstnd.gif

That graph page is beyond simple amusement; it is hilarious.

I'm glad you find it amusing, Gene. Now please explain
why EZNEC came up with that data based on the EZNEC
files that you are free to download and analyze.

All I did was simulate a coil using the helix feature
in EZNEC. For standing-waves, I left the coil un-
terminated. For traveling-waves, I terminated the
coil in close to its characteristic impedance. The
graphs are the exact data reported by EZNEC so
W7EL can be blamed for the results, not I.

Cecil,

OK, here is what I find amusing.

* EZNEC does not know or care about "standing waves" and "traveling
waves". As has been explained many times, the NEC-based simulation tools
simply look at the total current, without making any philosophical value
judgments about the mobility of the waves. It is clear that you have
loaded some sort of conditions into EZNEC that you believe represent
standing waves and traveling waves. However, the argument becomes
completely circular at that point, as you have loaded the conditions
that give exactly the results you desire. If there is a hidden "wave
type" parameter in EZNEC, please let us know. I will humbly retract my
criticism.

* You show those lovely equations for wave types, and then completely
avoid any further mention of the "t" factor. Yes, it is common to omit
the e^(jwt) term, but in this case that term is the entire point of the
discussion. You show something called "magnitude", although it is not
stated just what that means. It appears to be the maximum envelope of
the current for all times, but why that is tied to phase is not very clear.

* The comment "No phase information in the phase" is a real classic. Of
course there is phase information in the phase. What sort of double-talk
are you engaging in? Zero is a real number. The actual issue is one that
continues to elude you and many others. Phase needs to be carefully
defined for the case at hand. There are many definitions in use. It
would appear that you have chosen two different phases for the left and
right sides of your web page. You apparently have plotted the EZNEC
results shown on the lower portion of the page, but you have not
explained how those results connect to your equations.

In summary, if this page is intended to resolve any serious debate, it
does not. This stuff is already fully understood by everyone in the debate.

73,
Gene
W4SZ

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
AI4QJ wrote:
... it is plain and simple "intuitive" once you know that current
changes along the electrical "degree length" in an unloaded antenna,
the same should happen in the degree length loaded coil.

Unfortunately, both sides cannot be right but both sides
are still illustrated as fact in the ARRL Antenna Book.
There's one graphic that shows the drop in amplitude
through a loading coil and another that shows no change.
Apparently, the ARRL doesn't know what happens so they
show both possibilities as technically correct.

Also, as indicated, the pictures do say 1000 words and it also looks
like W8JI ended up agreeing with you after you pointed out the same
effect at "ON4UN's Low Band DXing", 3rd Edition, on page 9-34.

Unfortunately, it is rumored that W8JI has talked ON4UN
into changing that in the latest edition. I emailed ON4UN
about it but got no reply.

It has been changed. There is no longer any discussion of "degrees",
only "current".

73,
Gene
W4SZ

Loading Coils; was : Vincent antenna
 

"art" wrote
I NEVER SAID ANYTHING ABOUT ZERO RADIATION!
I am close to plonking you because of your twisted reading
just wastes my time.
_____________

art,

"The resultant vector of all vectors involved with radiation"
is ONE vector. If it "can NEVER be at right angles to the axis
of a radiator" then how can a monopole have any radiation
in such directions?

RF

Loading Coils; was : Vincent antenna
 

On Wed, 05 Dec 2007 15:43:11 GMT, Cecil Moore
wrote:

Richard Clark wrote:
Using what probes?

Toroidal current pickup coils designed by W7EL
with the standard voltage probes.

What size 600 ohm non-inductive resistors?

Loading Coils; was : Vincent antenna
 

On 5 Dec, 09:49, "Richard Fry" wrote:
"art" wrote I NEVER SAID ANYTHING ABOUT ZERO RADIATION!
I am close to plonking you because of your twisted reading
just wastes my time.

_____________

art,

"The resultant vector of all vectors involved with radiation"
is ONE vector. If it "can NEVER be at right angles to the axis
of a radiator" then how can a monopole have any radiation
in such directions?

RF

I have had it with you and your senior moments and misquotes.
I asked you to stop so you had fair warning
PLONK. Enough is enough
Art Unwin KB9MZ....xg (uk)

Loading Coils; was : Vincent antenna
 

Art wrote:
The resultant vector of all vectors involved with radiation can NEVER be
at right angles to the axis of the radiator. PERIOD."

A radial mode helix can and does work, despite Art`s apparent
disputation.

The radial mode helix acts as a stacked horizontal loop antenna. Hams
routinely use horizontal loops for more bandwidth with less drivepoint
resistance variation in a centerfed half wavelength of wire. When the
length of wire goes from 0,5 WL to 0.6 WL the dipole increases its
resistance from 70 ohms to 140 ohms. The loop feedpoint increases from 5
ohms to 7 ohms (theat`s less than a double as in the dipole. This
information is found in Figs 7-19 and 8-14 of Bailey`s "TV and Other
Receiving Antennas".

Best regards, Richard Harrison, KB5WZI

Loading Coils; was : Vincent antenna
 

Art wrote:
"The resultant vector of all vectors involved with radiation can NEVER
be at right angles to the axis of the radiator. PERIOD."

I`ve already defended the radial mode helix, but think of almost any
simple antenna. Doesn`t the half-wave dipole dradiate principally at
right angles to its axis?

Best regards, Richard Harrison, KB5WZI

Loading Coils; was : Vincent antenna
 

On Wed, 5 Dec 2007 10:38:40 -0800 (PST), art
wrote:

PLONK. Enough is enough
Writing PLONK is about as effective as trying to work DX by talking
into the back of a microphone Arthur.

73's
Richard Clark, KB7QHC