I take it that you are trying to learn and not just be argumentative.

If you read what I wrote, I said that in the antenna handbook that
they finally have it right.

Read the first three paragraphs under "TUNING TO A QUARTER WAVE"
below.

Regards
Gary


On Fri, 30 Apr 2004 00:07:54 -0400, "Doug Dotson"
wrote:

First you cite several instances that the ARRL treatment is
wrong. Then you say the they finally got it right. Where are
your references that substantiate either statement?

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
I tried to give an abbreviated synopsis of the subject and dispel some
myths. I did not cover all the details.

You need look no further than the ARRL itself for references. If you
read the whole post you would see that near the bottom I credited the
ARRL 2000 edition of their handbook, antenna section. The definition
of "radiation resistance" is from there and the calculations of the
example antenna with impedance's and voltages developed are directly
from there.

If you also look in the 18th edition 1997? of the ARRL antenna
handbook chapter 16 "mobile and marine antennas", and probably later
versions, you will see where they properly discuss loaded short
antennas and what the coil does.

Also if you look at the earlier post titled "Notes on short SSB
antennas" you will find a reference to W8JI's web site where he
discusses these very items in detail. He and many other engineers will
tell you the same thing.

I don't mean to discredit the ARRL but their statements in regard to
tuning an antenna to a quarter wave in their older publications are
misleading as evidenced by all the misconceptions that fly around.

While that is a simplified explanation of what happens with the
antenna matching, I suppose it was easier to propagate that (no pun
intended) term for simplicity. But if you really want to understand
what is going on it will get you into trouble in understanding as it
is a conflict with what really happens.

Regards
Gary




On Thu, 29 Apr 2004 20:25:53 -0400, "Doug Dotson"
wrote:

So, is this something you put together? How about some references?
ARRL is a pretty reputable outfit. If you are going to dispute their
writings, you should provide some some verifiable references.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
This tries to explain how short SSB antennas operate and why.
The discussion is concerning antennas that are shorter than a quarter
wavelength.

TUNING TO A QUARTER WAVE

I looked through several older handbooks and antenna handbooks and
found most of them professing what Larry is saying about "tuning an
antenna to an electrical quarter wave."

No wonder so many people have it wrong! The ARRL has been preaching
this stuff for years. But in the same paragraphs they will speak to
the "electrical length being very close to the physical length". Can't
have it both ways! Even the 2000 ARRL handbook has it wrong.

They finally got it right in their antenna handbook. Not once did I
see reference to "tuning an antenna to an electrical quarter wave
length.

It may seem like semantics but there are a lot of people that get
confused and think that when making the system resonant with a
shorter antenna that the antenna is really the same as a quarter wave
length antenna when there is a loading coil. It is far from that. Its
radiation resistance and its feed point resistance are both much
lower.

An antennas electrical length is what it is by itself. Adding a coil
to it to make it resonant will not change that.

Gary,

I'm not trying to be contrary at all. So much of what floats around on
this and other forums is totally anecdotal. When it comes to
electrical engineering I expect a more formal and verifiable approach.

More below.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
...
I take it that you are trying to learn and not just be argumentative.

Absolutely. I'm tired of this argument. I'd like to be up to date in
the current school of thought. Kind of like that myth that you need
to line your hull with yards of copper foil as a counterpoise when
emperical evedence says otherwise.

If you read what I wrote, I said that in the antenna handbook that
they finally have it right.

But the only reference you cite is the ARRL Antenna Handbook.
When you say they finally got it right, you must base that on something
other than the handbook itself. When you said they were wrong for so
many years, you gave no reference that supports that view. When you
say they finally got it right you still gave no reference to support that
suposition. So what it boils down to is that the handbook used to be
wrong, now is right, and you are the judge as to what was right and wrong
with no independently verifiable refererence to either position. I expect
this from the government, but I cannot accept if from someone that
appears have a reasonable engineering background.

Read the first three paragraphs under "TUNING TO A QUARTER WAVE"
below.

I have read it. No reference other than the ARRL itself which used to be
wrong and now is right.

Regards
Gary


On Fri, 30 Apr 2004 00:07:54 -0400, "Doug Dotson"
wrote:

First you cite several instances that the ARRL treatment is
wrong. Then you say the they finally got it right. Where are
your references that substantiate either statement?

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
I tried to give an abbreviated synopsis of the subject and dispel some
myths. I did not cover all the details.

You need look no further than the ARRL itself for references. If you
read the whole post you would see that near the bottom I credited the
ARRL 2000 edition of their handbook, antenna section. The definition
of "radiation resistance" is from there and the calculations of the
example antenna with impedance's and voltages developed are directly
from there.

If you also look in the 18th edition 1997? of the ARRL antenna
handbook chapter 16 "mobile and marine antennas", and probably later
versions, you will see where they properly discuss loaded short
antennas and what the coil does.

Also if you look at the earlier post titled "Notes on short SSB
antennas" you will find a reference to W8JI's web site where he
discusses these very items in detail. He and many other engineers will
tell you the same thing.

I don't mean to discredit the ARRL but their statements in regard to
tuning an antenna to a quarter wave in their older publications are
misleading as evidenced by all the misconceptions that fly around.

While that is a simplified explanation of what happens with the
antenna matching, I suppose it was easier to propagate that (no pun
intended) term for simplicity. But if you really want to understand
what is going on it will get you into trouble in understanding as it
is a conflict with what really happens.

Regards
Gary




On Thu, 29 Apr 2004 20:25:53 -0400, "Doug Dotson"
wrote:

So, is this something you put together? How about some references?
ARRL is a pretty reputable outfit. If you are going to dispute their
writings, you should provide some some verifiable references.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
This tries to explain how short SSB antennas operate and why.
The discussion is concerning antennas that are shorter than a
quarter
wavelength.

TUNING TO A QUARTER WAVE

I looked through several older handbooks and antenna handbooks and
found most of them professing what Larry is saying about "tuning an
antenna to an electrical quarter wave."

No wonder so many people have it wrong! The ARRL has been preaching
this stuff for years. But in the same paragraphs they will speak to
the "electrical length being very close to the physical length".
Can't
have it both ways! Even the 2000 ARRL handbook has it wrong.

They finally got it right in their antenna handbook. Not once did I
see reference to "tuning an antenna to an electrical quarter wave
length.

It may seem like semantics but there are a lot of people that get
confused and think that when making the system resonant with a
shorter antenna that the antenna is really the same as a quarter
wave
length antenna when there is a loading coil. It is far from that.
Its
radiation resistance and its feed point resistance are both much
lower.

An antennas electrical length is what it is by itself. Adding a coil
to it to make it resonant will not change that.

I am not sure just what you are missing here. Or maybe I am not
understanding your question.

Again I am posting the reference pages below in the antenna handbook.
Not once could I find in there that they stated that a loading coil on
an antenna made it into a quarter wave antenna as did earlier versions
of the antenna handbook and the regular handbook. That is why I say
they finally got it right. Maybe you are questioning which one is
right.

In the earlier handbooks the subject was more or less glossed over
with poor explanation of what happens in the antenna matching. The
newer antenna handbook goes into more detail.

I even tell you the pages!

Also if you look at my earlier post "Notes on short SSB antennas"
there is a link to W8JI's web site where he discusses the same stuff
that I have. He tells you why a loaded antenna is still the same
length electrically as an unloaded antenna. In that post there is a
copy of part of his article that deals with this topic as I credited
him with.
For more details look at his web site.

REFERENCE 1

If you also look in the 18th edition 1997? of the ARRL antenna
handbook chapter 16 "mobile and marine antennas", and probably later
versions, you will see where they properly discuss loaded short
antennas and what the coil does.

REFERENCE 2

Also if you look at the earlier post titled "Notes on short SSB
antennas" you will find a reference to W8JI's web site where he
discusses these very items in detail. He and many other engineers will
tell you the same thing.

Regards
Gary



On Fri, 30 Apr 2004 17:51:34 -0400, "Doug Dotson"
wrote:

Gary,

I'm not trying to be contrary at all. So much of what floats around on
this and other forums is totally anecdotal. When it comes to
electrical engineering I expect a more formal and verifiable approach.

More below.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
I take it that you are trying to learn and not just be argumentative.

Absolutely. I'm tired of this argument. I'd like to be up to date in
the current school of thought. Kind of like that myth that you need
to line your hull with yards of copper foil as a counterpoise when
emperical evedence says otherwise.

If you read what I wrote, I said that in the antenna handbook that
they finally have it right.

But the only reference you cite is the ARRL Antenna Handbook.
When you say they finally got it right, you must base that on something
other than the handbook itself. When you said they were wrong for so
many years, you gave no reference that supports that view. When you
say they finally got it right you still gave no reference to support that
suposition. So what it boils down to is that the handbook used to be
wrong, now is right, and you are the judge as to what was right and wrong
with no independently verifiable refererence to either position. I expect
this from the government, but I cannot accept if from someone that
appears have a reasonable engineering background.

Read the first three paragraphs under "TUNING TO A QUARTER WAVE"
below.

I have read it. No reference other than the ARRL itself which used to be
wrong and now is right.

Regards
Gary


On Fri, 30 Apr 2004 00:07:54 -0400, "Doug Dotson"
wrote:

First you cite several instances that the ARRL treatment is
wrong. Then you say the they finally got it right. Where are
your references that substantiate either statement?

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
I tried to give an abbreviated synopsis of the subject and dispel some
myths. I did not cover all the details.

You need look no further than the ARRL itself for references. If you
read the whole post you would see that near the bottom I credited the
ARRL 2000 edition of their handbook, antenna section. The definition
of "radiation resistance" is from there and the calculations of the
example antenna with impedance's and voltages developed are directly
from there.

If you also look in the 18th edition 1997? of the ARRL antenna
handbook chapter 16 "mobile and marine antennas", and probably later
versions, you will see where they properly discuss loaded short
antennas and what the coil does.

Also if you look at the earlier post titled "Notes on short SSB
antennas" you will find a reference to W8JI's web site where he
discusses these very items in detail. He and many other engineers will
tell you the same thing.

I don't mean to discredit the ARRL but their statements in regard to
tuning an antenna to a quarter wave in their older publications are
misleading as evidenced by all the misconceptions that fly around.

While that is a simplified explanation of what happens with the
antenna matching, I suppose it was easier to propagate that (no pun
intended) term for simplicity. But if you really want to understand
what is going on it will get you into trouble in understanding as it
is a conflict with what really happens.

Regards
Gary




On Thu, 29 Apr 2004 20:25:53 -0400, "Doug Dotson"
wrote:

So, is this something you put together? How about some references?
ARRL is a pretty reputable outfit. If you are going to dispute their
writings, you should provide some some verifiable references.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
This tries to explain how short SSB antennas operate and why.
The discussion is concerning antennas that are shorter than a
quarter
wavelength.

TUNING TO A QUARTER WAVE

I looked through several older handbooks and antenna handbooks and
found most of them professing what Larry is saying about "tuning an
antenna to an electrical quarter wave."

No wonder so many people have it wrong! The ARRL has been preaching
this stuff for years. But in the same paragraphs they will speak to
the "electrical length being very close to the physical length".
Can't
have it both ways! Even the 2000 ARRL handbook has it wrong.

They finally got it right in their antenna handbook. Not once did I
see reference to "tuning an antenna to an electrical quarter wave
length.

It may seem like semantics but there are a lot of people that get
confused and think that when making the system resonant with a
shorter antenna that the antenna is really the same as a quarter
wave
length antenna when there is a loading coil. It is far from that.
Its
radiation resistance and its feed point resistance are both much
lower.

An antennas electrical length is what it is by itself. Adding a coil
to it to make it resonant will not change that.

I guess I'll pick up the latest Antenna Handbook and start reading.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
...
I am not sure just what you are missing here. Or maybe I am not
understanding your question.

Again I am posting the reference pages below in the antenna handbook.
Not once could I find in there that they stated that a loading coil on
an antenna made it into a quarter wave antenna as did earlier versions
of the antenna handbook and the regular handbook. That is why I say
they finally got it right. Maybe you are questioning which one is
right.

In the earlier handbooks the subject was more or less glossed over
with poor explanation of what happens in the antenna matching. The
newer antenna handbook goes into more detail.

I even tell you the pages!

Also if you look at my earlier post "Notes on short SSB antennas"
there is a link to W8JI's web site where he discusses the same stuff
that I have. He tells you why a loaded antenna is still the same
length electrically as an unloaded antenna. In that post there is a
copy of part of his article that deals with this topic as I credited
him with.
For more details look at his web site.

REFERENCE 1

If you also look in the 18th edition 1997? of the ARRL antenna
handbook chapter 16 "mobile and marine antennas", and probably later
versions, you will see where they properly discuss loaded short
antennas and what the coil does.

REFERENCE 2

Also if you look at the earlier post titled "Notes on short SSB
antennas" you will find a reference to W8JI's web site where he
discusses these very items in detail. He and many other engineers
will
tell you the same thing.

Regards
Gary



On Fri, 30 Apr 2004 17:51:34 -0400, "Doug Dotson"
wrote:

Gary,

I'm not trying to be contrary at all. So much of what floats around on
this and other forums is totally anecdotal. When it comes to
electrical engineering I expect a more formal and verifiable approach.

More below.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
I take it that you are trying to learn and not just be argumentative.

Absolutely. I'm tired of this argument. I'd like to be up to date in
the current school of thought. Kind of like that myth that you need
to line your hull with yards of copper foil as a counterpoise when
emperical evedence says otherwise.

If you read what I wrote, I said that in the antenna handbook that
they finally have it right.

But the only reference you cite is the ARRL Antenna Handbook.
When you say they finally got it right, you must base that on something
other than the handbook itself. When you said they were wrong for so
many years, you gave no reference that supports that view. When you
say they finally got it right you still gave no reference to support that
suposition. So what it boils down to is that the handbook used to be
wrong, now is right, and you are the judge as to what was right and wrong
with no independently verifiable refererence to either position. I expect
this from the government, but I cannot accept if from someone that
appears have a reasonable engineering background.

Read the first three paragraphs under "TUNING TO A QUARTER WAVE"
below.

I have read it. No reference other than the ARRL itself which used to be
wrong and now is right.

Regards
Gary


On Fri, 30 Apr 2004 00:07:54 -0400, "Doug Dotson"
wrote:

First you cite several instances that the ARRL treatment is
wrong. Then you say the they finally got it right. Where are
your references that substantiate either statement?

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
I tried to give an abbreviated synopsis of the subject and dispel
some
myths. I did not cover all the details.

You need look no further than the ARRL itself for references. If you
read the whole post you would see that near the bottom I credited
the
ARRL 2000 edition of their handbook, antenna section. The definition
of "radiation resistance" is from there and the calculations of the
example antenna with impedance's and voltages developed are
directly
from there.

If you also look in the 18th edition 1997? of the ARRL antenna
handbook chapter 16 "mobile and marine antennas", and probably later
versions, you will see where they properly discuss loaded short
antennas and what the coil does.

Also if you look at the earlier post titled "Notes on short SSB
antennas" you will find a reference to W8JI's web site where he
discusses these very items in detail. He and many other engineers
will
tell you the same thing.

I don't mean to discredit the ARRL but their statements in regard to
tuning an antenna to a quarter wave in their older publications are
misleading as evidenced by all the misconceptions that fly around.

While that is a simplified explanation of what happens with the
antenna matching, I suppose it was easier to propagate that (no pun
intended) term for simplicity. But if you really want to understand
what is going on it will get you into trouble in understanding as it
is a conflict with what really happens.

Regards
Gary




On Thu, 29 Apr 2004 20:25:53 -0400, "Doug Dotson"
wrote:

So, is this something you put together? How about some references?
ARRL is a pretty reputable outfit. If you are going to dispute
their
writings, you should provide some some verifiable references.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
This tries to explain how short SSB antennas operate and why.
The discussion is concerning antennas that are shorter than a
quarter
wavelength.

TUNING TO A QUARTER WAVE

I looked through several older handbooks and antenna handbooks
and
found most of them professing what Larry is saying about "tuning
an
antenna to an electrical quarter wave."

No wonder so many people have it wrong! The ARRL has been
preaching
this stuff for years. But in the same paragraphs they will speak
to
the "electrical length being very close to the physical length".
Can't
have it both ways! Even the 2000 ARRL handbook has it wrong.

They finally got it right in their antenna handbook. Not once did
I
see reference to "tuning an antenna to an electrical quarter wave
length.

It may seem like semantics but there are a lot of people that get
confused and think that when making the system resonant with a
shorter antenna that the antenna is really the same as a quarter
wave
length antenna when there is a loading coil. It is far from that.
Its
radiation resistance and its feed point resistance are both much
lower.

An antennas electrical length is what it is by itself. Adding a
coil
to it to make it resonant will not change that.

"Doug Dotson" wrote ...
I guess I'll pick up the latest Antenna Handbook and start reading.

Doug, k3qt
s/v Callista

The fundamental work on "small" antennas was done by a guy named Wheeler. After
digging in the filing cabinet I found his paper from the proceedings of the
I.R.E. (institute of radio engineers?) that preceded the IEEE.

"Fundamental Limitations of Small Antennas" by Harold A. Wheeler fellow, I.R.E.
December 1947

One insight is that a small antenna can theoretically be nearly as efficient as
a 1/4 wave element but it is difficult to match to the small radiation
resistance. (actually you match to the sum of the radiation and loss
resistance). The efficiency is simply the ratio of radiation resistance to the
sum of radiation plus loss resistance. A small loop antenna which looks
inductive makes the job easier as you can build a low resistance loop and use
high Q capacitors for tuning/matching.

regards,
-rick-

"-rick-" wrote in
:


"Doug Dotson" wrote ...
I guess I'll pick up the latest Antenna Handbook and start reading.

Doug, k3qt
s/v Callista

The fundamental work on "small" antennas was done by a guy named
Wheeler. After digging in the filing cabinet I found his paper from
the proceedings of the I.R.E. (institute of radio engineers?) that
preceded the IEEE.

"Fundamental Limitations of Small Antennas" by Harold A. Wheeler
fellow, I.R.E. December 1947

One insight is that a small antenna can theoretically be nearly as
efficient as a 1/4 wave element but it is difficult to match to the
small radiation resistance. (actually you match to the sum of the
radiation and loss resistance). The efficiency is simply the ratio of
radiation resistance to the sum of radiation plus loss resistance. A
small loop antenna which looks inductive makes the job easier as you
can build a low resistance loop and use high Q capacitors for
tuning/matching.

regards,
-rick-

In 1947, matching the very low impedance feedpoint of a loaded vertical
antenna was a problem. But, after the invention of the broadband iron
powder toroids that are very efficient, magnetically at high frequencies,
it's not much of a problem at all.

At the base of my monster 1.8-30 Mhz 15' mobile ham antenna (4' ss base, 6"
diameter monster loading coil, 3' mast, 36" capacitor hat and stainless
whip on top cut so that shorting the whole coil resonates it at 14.250 Mhz)
is a T-200-2 powered iron toroid core wrapped with insulating fiberglass
tape and 12 turns of bare #10 copper. The core is mounted in a plastic
construction box between the posts of banana jacks that are soldered to the
outside of each turn so banana plugs can select the turns ratio. One end
of the coil is connected to "ground", the chassis of the car. Any
reasonable RF grounding system would hook there on a boat. The coax from
the transceiver's 650 watt, 12V linear amp is terminated with a banana plug
to select the input tap, and a short length of braided strap goes between a
banana plug and the bottom feed point of the antenna for the output tap.
Best match occurs when the lowest reflected power occurs on the SWR meter
of the linear amp (or transceiver with the linear out of the circuit). On
my antenna, on the 3.5-4 Mhz ham band for instance, the input tap is across
the entire 12 turns and the antenna is tapped 4 turns above the ground
point. SWR at resonance is perfect, 1:1, and large corona arcs occur at
the top of the whip tip and bent around ends of the 8 spokes of the 36"
capacitor hat, made of stainless welding rod welded to two large
flatwashers at the center. Signals are very comparible to any fixed
station here running the same power. Cars passing blow horns and shout,
"Your Antenna Is On Fire!", out their windows. It will light up a
flourescent tube in your hand at 10' away, easily.

The square of the turns ratio is 9:1 so the antenna's impedance is
somewhere around 6 ohms or so at the feedpoint. The 650 W amp melted the
solder joints on the core using #12 wire for the turns, so I went to #10
which is about as thick as I can go with 12 evenly spaced turns without
shorts. #10 wire gets too hot to touch, but doesn't melt solder any
more...(c; A second similar toroid autotransformer is mounted in another
box with 24 turns of #12 next to the first. It is used for the 160 Meter
band (1.8-2 Mhz). A second loading coil on top of the first (3" diam,
200T) adds sufficient inductance to tune the 15' antenna down to 1.8 Mhz,
but at 650 watts there is so much corona arcing it makes the SWR readings
go crazy so power is reduced to 300W or whatever the humidity around the
antenna can stand at that particular moment.

If one were to forego the old untuned wire/tuner marine antenna
configuration and go with a real tuned vertical, this toroid
autotransformer will very efficiently match the very low base impedance to
the 50 ohm transceiver across the 2-30 Mhz HF band.

The car's electrical wiring resonates around 3.9 Mhz, causing all the dash
lights to glow brightly with SSB modulation on their own, to the amazement
of even ham radio passengers. Thank God old Mercedes 220D diesels have no
electronics in them!

Many hams have gone to a remotely-tuned mobile antenna that uses a powered
motor to move the tap on a center loading coil. Here's what it looks like:
http://www.qth.com/n7lyy/about.html
It uses a screwdriver DC motor to move the loading coil up and down against
a large contactor and will tune the entire band. If a boater were to make
the whip longer than the 66" limit for cars, it would be even more
efficient with less coil turns below 12 Mhz. 66" is so it will tune 29.7
Mhz, the highest HF ham band boaters don't need. This antenna system would
easily mount on a stern rail, using the rail as groundplane if it were all
connected together, and would tune from the radio while watching the SWR
meter on the radio (or output power meter which would just tune for maximum
output power).

Larry W4CSC

Some day I might try this antenna using the handrails of the boat as ground
plane. It's gotta work better than the stupid untuned backstay and
inefficient antenna tuner. It certainly results in much better signal
reports.

On Tue, 04 May 2004 15:08:08 -0000, Larry W4CSC
wrote:


The square of the turns ratio is 9:1 so the antenna's impedance is
somewhere around 6 ohms or so at the feedpoint. The 650 W amp melted the
solder joints on the core using #12 wire for the turns, so I went to #10

If one were to forego the old untuned wire/tuner marine antenna
configuration and go with a real tuned vertical, this toroid
autotransformer will very efficiently match the very low base impedance to
the 50 ohm transceiver across the 2-30 Mhz HF band.


Larry W4CSC

Some day I might try this antenna using the handrails of the boat as ground
plane. It's gotta work better than the stupid untuned backstay and
inefficient antenna tuner. It certainly results in much better signal
reports.


Your feed point resistance may be 6 ohms but about 5.8 to 5.9 ohms of
that are coil resistance. The radiation resistance of the 15 foot whip
on 3.5 mhz is in the order of .1 ohm.

So about 97% of your power is going up in heat in the coils. Only a
couple percent of the power is making it to the antenna to be
radiated.
Of 650 watts only around 20 watts makes it to the antenna.

A full quarter wave length vertical has a radiation and feed point
resistance of around 36 ohms. Much easier to get power into than a .1
ohm 15 foot antenna.

Oh, don't forget to add in all the ground loss resistance too. Less
power to the antenna yet.

If you can get your feed point resistance down to around 1 ohm then
you will get about 10% of your power into the 15 foot antenna!

Regards
Gary

Here's some more information on screwdriver HF antennas:

http://www.qsl.net/k4kwh/
http://www.hsantennas.com/
http://www.kj7u.com/
http://www.ko6yd.com/sam/index.htm
(screwdriver antenna memory tuner)
http://www.mfjenterprises.com/produc...rodid=MFJ-1662
http://texasbugcatcher.com/
(my antenna uses Henry's coils but is not a screwdriver.)
http://www.mindspring.com/~k4poz/

As you can see, these antennas are very respected by the finicky ham radio
mobile operators. They'll ALL tune ALL the marine bands.

Larry W4CSC

I wonder if Gary writes for World Radio magazine under the pen name of Kurt
N Sturba?
Doug K7ABX
"Gary Schafer" wrote in message
...
I take it that you are trying to learn and not just be argumentative.

If you read what I wrote, I said that in the antenna handbook that
they finally have it right.

Read the first three paragraphs under "TUNING TO A QUARTER WAVE"
below.

Regards
Gary


On Fri, 30 Apr 2004 00:07:54 -0400, "Doug Dotson"
wrote:

First you cite several instances that the ARRL treatment is
wrong. Then you say the they finally got it right. Where are
your references that substantiate either statement?

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
I tried to give an abbreviated synopsis of the subject and dispel some
myths. I did not cover all the details.

You need look no further than the ARRL itself for references. If you
read the whole post you would see that near the bottom I credited the
ARRL 2000 edition of their handbook, antenna section. The definition
of "radiation resistance" is from there and the calculations of the
example antenna with impedance's and voltages developed are directly
from there.

If you also look in the 18th edition 1997? of the ARRL antenna
handbook chapter 16 "mobile and marine antennas", and probably later
versions, you will see where they properly discuss loaded short
antennas and what the coil does.

Also if you look at the earlier post titled "Notes on short SSB
antennas" you will find a reference to W8JI's web site where he
discusses these very items in detail. He and many other engineers will
tell you the same thing.

I don't mean to discredit the ARRL but their statements in regard to
tuning an antenna to a quarter wave in their older publications are
misleading as evidenced by all the misconceptions that fly around.

While that is a simplified explanation of what happens with the
antenna matching, I suppose it was easier to propagate that (no pun
intended) term for simplicity. But if you really want to understand
what is going on it will get you into trouble in understanding as it
is a conflict with what really happens.

Regards
Gary




On Thu, 29 Apr 2004 20:25:53 -0400, "Doug Dotson"
wrote:

So, is this something you put together? How about some references?
ARRL is a pretty reputable outfit. If you are going to dispute their
writings, you should provide some some verifiable references.

Doug, k3qt
s/v Callista

"Gary Schafer" wrote in message
.. .
This tries to explain how short SSB antennas operate and why.
The discussion is concerning antennas that are shorter than a
quarter
wavelength.

TUNING TO A QUARTER WAVE

I looked through several older handbooks and antenna handbooks and
found most of them professing what Larry is saying about "tuning an
antenna to an electrical quarter wave."

No wonder so many people have it wrong! The ARRL has been preaching
this stuff for years. But in the same paragraphs they will speak to
the "electrical length being very close to the physical length".
Can't
have it both ways! Even the 2000 ARRL handbook has it wrong.

They finally got it right in their antenna handbook. Not once did I
see reference to "tuning an antenna to an electrical quarter wave
length.

It may seem like semantics but there are a lot of people that get
confused and think that when making the system resonant with a
shorter antenna that the antenna is really the same as a quarter
wave
length antenna when there is a loading coil. It is far from that.
Its
radiation resistance and its feed point resistance are both much
lower.

An antennas electrical length is what it is by itself. Adding a coil
to it to make it resonant will not change that.

"Doug" wrote in
.net:

I wonder if Gary writes for World Radio magazine under the pen name of
Kurt N Sturba?
Doug K7ABX

Hee hee....(c;

World Radio is the definitive answer to all broadcast engineering
questions....

73, Larry W4CSC