"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

"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.

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

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

Gary Schafer wrote in
:

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

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


I've never met anyone so full of pure bull**** in my entire life as you,
Gary. It's simply incredible.

One hopes noone in their right mind will hire you as an engineer and suffer
the consequences.

I doubt 20 watts would make a signal 800 miles away at 20 over S9 in any
conditions, but we're, I'm sure, gonna hear more bull**** from you about it
in the near future.

Larry W4CSC

What class licenses and degrees do you hold, anyways? I've been a 1st
phone licensee since the 1960's, an avid ham operator since 1957 when I was
10 and graduated with honors from many military electronics schools run by
the US Navy because Vietnam's draft kinda got in the way of college in
1964.

Stop by some time and I'll let 20 watts burn your ass for you....(c;
I've never seen 20 watts produce a corona in air over 8" long....
How many kilovolts is that in air at sea level?

On Tue, 04 May 2004 21:15:40 -0000, Larry W4CSC
wrote:

Gary Schafer wrote in
:

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

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


I've never met anyone so full of pure bull**** in my entire life as you,
Gary. It's simply incredible.

One hopes noone in their right mind will hire you as an engineer and suffer
the consequences.

I doubt 20 watts would make a signal 800 miles away at 20 over S9 in any
conditions, but we're, I'm sure, gonna hear more bull**** from you about it
in the near future.

Larry W4CSC

What class licenses and degrees do you hold, anyways? I've been a 1st
phone licensee since the 1960's, an avid ham operator since 1957 when I was
10 and graduated with honors from many military electronics schools run by
the US Navy because Vietnam's draft kinda got in the way of college in
1964.

Stop by some time and I'll let 20 watts burn your ass for you....(c;
I've never seen 20 watts produce a corona in air over 8" long....
How many kilovolts is that in air at sea level?


Heh heh, still haven't figured it out Larry?

Regards
Gary

On Tue, 04 May 2004 21:15:40 -0000, Larry W4CSC
wrote:

Gary Schafer wrote in
:

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

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


I've never met anyone so full of pure bull**** in my entire life as you,
Gary. It's simply incredible.

One hopes noone in their right mind will hire you as an engineer and suffer
the consequences.

I doubt 20 watts would make a signal 800 miles away at 20 over S9 in any
conditions, but we're, I'm sure, gonna hear more bull**** from you about it
in the near future.

Larry W4CSC

What class licenses and degrees do you hold, anyways? I've been a 1st
phone licensee since the 1960's, an avid ham operator since 1957 when I was
10 and graduated with honors from many military electronics schools run by
the US Navy because Vietnam's draft kinda got in the way of college in
1964.

Stop by some time and I'll let 20 watts burn your ass for you....(c;
I've never seen 20 watts produce a corona in air over 8" long....
How many kilovolts is that in air at sea level?


What part do you deem to be "bull****" Larry? The parts you don't
understand?

I know that you like sensationalism in big arcs and bragging rights of
running high power. That's fine if that's your thing but you let it
cloud reality. Being able to pull a big arc from an antenna tells you
nothing about its efficiency or how well it will radiate. It does make
for good show though. A tesla coil will produce some pretty high
voltage and corona too.

By the way, time in grade doesn't count either. Being a corporal for
20 years doesn't automatically make one an expert at anything. Not
that you can't be an expert, time in grade just doesn't contribute.

Note that I haven't said that you are full of bull****. I am giving
you the benefit of the doubt.

If you went to tech school as you claim, you have forgotten some of
the basics or you were asleep through many parts.

I would have thought that basic AC circuit theory would have been part
of your education. Maybe not.


If you are interested in how this stuff really works it might help us
to understand some of the things that you have misconceptions about.

Here are a few questions:

1. Do you understand that when you have a capacitor and a coil in
series in an AC circuit that the voltage across either can be much
greater than the applied voltage to the circuit? (basic AC theory)

2. Do you understand that a coil has series resistance as well as
reactance?

3. Do you understand the difference between Radiation resistance and
feed point resistance? This is an important one!

4. Do you know that Radiation resistance is in series with feed point
resistance.

5. Do you know that the same amount of current that flows at the feed
point of the antenna is the same amount that flows in the radiation
resistance of the antenna? They are in series you know.

6. I assume that you know ohms law and that if the same amount of
current flows in two series resistors that the larger resistance will
dissipate more power than the lower value resistor?

7. Do you understand that there is a phase shift between current and
voltage across a coil in an AC circuit.

8. Do you understand that the radiation resistance gets very low in a
short antenna?

If you do not understand any of the above questions please let us
know. That may be the reason that you are not understanding what goes
on in your antenna system.

What I previously wrote pertaining to the voltage developed across the
coil and how low the radiation resistance can be on a short antenna
was quoted directly from the 2000 ARRL handbook. If you have it look
at HF mobile antennas. Page 20.46, 3rd column on the page. It explains
why the voltage is 5000 volts rms across the coil with just 100 watts
applied to an antenna with a radiation resistance of less than an ohm.
Isn't that amazing! Must be black magic huh Larry? Or just maybe it
has something to do with the above questions.

Regards
Gary

I'm gonna jump in here -- not as an expert on antennas, but
merely as someone who understands maxwell's equations
and some mathematics.

On 2004-05-05, Gary Schafer wrote:

If you are interested in how this stuff really works it might help us
to understand some of the things that you have misconceptions about.

I don't think that it'll help at all to know what (if anything)
he has misconceptions about. But it *would* help to have a
mathematical model and a definition of terms.


OK. Gary says that "your history doesn't matter; it doesn't matter
what tech school you went to, etc.", and I agree to some extent. Since
I didn't go to any tech school, I've got nothing to be embarassed
about. I just happen to know a bit of math and physics.


Here are a few questions:

2. Do you understand that a coil has series resistance as well as
reactance?

Wow. That's interesting. I'm just going to take a shot in the dark
and assume that by "series resistance" you mean if I apply
a DC voltage across the coil, and wait until the circuit reaches
a steady state, I'll notice some current flowing; the ratio
of the voltage applied to the steady-state current flow is
what I call "series resistance." [...and you're implicitly asserting
that this ratio is independent of the voltage applied, i.e., that
the steady state current is linear as a function of the applied
voltage"...] I expect that this assertion is true.

So in other words, what you're calling "series resistance" is
the real part of the (complex number) impedance, and reactance
is the imaginary part.

From what I've seen Larry write, I'll bet he understands that.


3. Do you understand the difference between Radiation resistance and
feed point resistance? This is an important one!

I'm just a farmer from the country, but where I come from, there's
just impedance. I don't know how you split the real part of that
complex number into two parts. Maybe where you come from, there's
"carbon resistor" resistance and "thin-film" resistance, too, but
I'm not sure how the electrons can tell the difference.


A Google search doesn't yield any real information on "feed point
resistance," so I guess that answering for myself, I can say
"sure...radiation resistance is the real part of the impedance of an
antenna; feed point resistance is an undefined term."

There *does* seem to be widespread use of the term "feedpoint
resistance," although definitions seem to be scarce as hen's
teeth. Just being the ignorant sorta guy I am, I tend to
gravitate towards the ones that define "feedpoint impedance;"
one could then say that feedpoint resistance is the real part
of that complex impedance. But that seems strikingly similar
to the definition of "radiation resistance." How very odd.

4. Do you know that Radiation resistance is in series with feed point
resistance.

Ah...now you're losing me. For me, one of those terms is undefined,
so it's hard to be "in series with" the other. And if we take
"feed point" to be "feedpoint," then since the two seem to be
the same, it's hard to admit that they're in series. But I'm sure
you can clear this up for me. Can you just write down the
equations? (with all the symbols defined -- that'll make it
much clearer).

5. Do you know that the same amount of current that flows at the feed
point of the antenna is the same amount that flows in the radiation
resistance of the antenna? They are in series you know.

"Flows in the radiation resistance?" I don't honestly know whether
Larry knows more or less than you do, but at least I've never seen him
write something like this.

6. I assume that you know ohms law and that if the same amount of
current flows in two series resistors that the larger resistance will
dissipate more power than the lower value resistor?

Um...Ohm's law tells me, if I recall correctly, that for certain
materials, the current flowing through them varies linearly with the
applied (DC) voltage; in these cases, the ratio of the two is called
the "resistance." If you think I'm being overly pedantic here, you can
ask "what's the resistance of a diode?" The answer is, of course,
"the current through a diode does not vary linearly as a function
of the applied voltage, so it does not have a resistance."
So you have to be careful about applying Ohm's law...

7. Do you understand that there is a phase shift between current and
voltage across a coil in an AC circuit.

I would say "an inductor has a complex impedance that happens not to
be a real number, but rather one that has an imaginary part as well."

8. Do you understand that the radiation resistance gets very low in a
short antenna?

Uh...I guess I don't "understand" that. But if you'd write
out an equation or two, I might know what you meant by it.

----------------------------------------------------------

Someone else asked a very interesting question earlier:

1. You state that some editions of some ARRL publication are wrong.
2. You state that other editions are right.

You haven't told us where one finds evidence for this
wrongness/correctness. Does one of them have an error in some
equation? Can you construct a real circuit for which the
predictions of one book are wrong and the predictions of the
other are correct? Or do we just have to take your word
for it that one is right, the other wrong? If it's the
latter, then why bring the ARRL into it? Why don't we just
agree that whatever you say is right, and whatever anyone
says that appears to contradict it is wrong? It'd save a lot
of writing...

statement about antennas paraphrasing ARRL ahndbook deleted
Isn't that amazing! Must be black magic huh Larry? Or just maybe it
has something to do with the above questions.

Maybe...but I'd find it more compelling if it had something to
do with known (by which I mean "widely accepted and tested")
physical laws like Maxwell's equations, and an analysis of
the circuits in question.

--John Hughes

-------------------------------------------------------------------------
On Wed, 5 May 2004 09:46:52 +0000 (UTC), "John F. Hughes"
wrote:



I'm gonna jump in here -- not as an expert on antennas, but
merely as someone who understands maxwell's equations
and some mathematics.

Well I don't profess to be any kind of expert either.


On 2004-05-05, Gary Schafer wrote:

If you are interested in how this stuff really works it might help us
to understand some of the things that you have misconceptions about.

I don't think that it'll help at all to know what (if anything)
he has misconceptions about. But it *would* help to have a
mathematical model and a definition of terms.

The fact that ALL this stuff has been gone over several times and he
still makes blanket statements of how it is wrong makes one wonder
where the problem really is.



OK. Gary says that "your history doesn't matter; it doesn't matter
what tech school you went to, etc.", and I agree to some extent. Since
I didn't go to any tech school, I've got nothing to be embarassed
about. I just happen to know a bit of math and physics.

Not really what I said. I said that "time in grade doesn't matter".
Not trying to belittle anyone's education pro or con.



Here are a few questions:

2. Do you understand that a coil has series resistance as well as
reactance?

Wow. That's interesting. I'm just going to take a shot in the dark
and assume that by "series resistance" you mean if I apply
a DC voltage across the coil, and wait until the circuit reaches
a steady state, I'll notice some current flowing; the ratio
of the voltage applied to the steady-state current flow is
what I call "series resistance." [...and you're implicitly asserting
that this ratio is independent of the voltage applied, i.e., that
the steady state current is linear as a function of the applied
voltage"...] I expect that this assertion is true.

So in other words, what you're calling "series resistance" is
the real part of the (complex number) impedance, and reactance
is the imaginary part.

From what I've seen Larry write, I'll bet he understands that.

Yes, the series resistance is the "real part". However it is not just
the DC resistance of the material in the coil. It is the AC resistance
of the material known as skin effect, which will be greater than the
DC resistance at radio frequencies. The higher the frequency the
greater the skin effect. The voltage applied is irrelevant.



3. Do you understand the difference between Radiation resistance and
feed point resistance? This is an important one!

I'm just a farmer from the country, but where I come from, there's
just impedance. I don't know how you split the real part of that
complex number into two parts. Maybe where you come from, there's
"carbon resistor" resistance and "thin-film" resistance, too, but
I'm not sure how the electrons can tell the difference.


A Google search doesn't yield any real information on "feed point
resistance," so I guess that answering for myself, I can say
"sure...radiation resistance is the real part of the impedance of an
antenna; feed point resistance is an undefined term."

There *does* seem to be widespread use of the term "feedpoint
resistance," although definitions seem to be scarce as hen's
teeth. Just being the ignorant sorta guy I am, I tend to
gravitate towards the ones that define "feedpoint impedance;"
one could then say that feedpoint resistance is the real part
of that complex impedance. But that seems strikingly similar
to the definition of "radiation resistance." How very odd.

This is the very reason I pose the question! By making presumptions
you get yourself into trouble in understanding. Don't feel alone
though, because this is probably one of the most misunderstood terms
with antennas.
Again, I don't claim to be any sort of expert here. If you read the
original post in this thread it attempts to explain it with some
references too.

But in a nut shell, "radiation resistance" is an imaginary term when
dealing with antenna radiation. It is the amount of resistance that it
would take to dissipate the same amount of power that actually is
being radiated. It is pure resistance. No reactance involved.


FEED POINT RESISTANCE, on the other hand is the resistance (assuming a
vertical whip antenna here) seen at the base of the antenna , the
feed point. It includes the radiation resistance of the antenna, the
loss resistance of any coil involved and the ground resistance. They
are all in series. This is with the reactance tuned out so the feed
point is purely resistive. Feed point impedance would be the same
thing but it may have reactance. In other words not purely resistive.


4. Do you know that Radiation resistance is in series with feed point
resistance.

Ah...now you're losing me. For me, one of those terms is undefined,
so it's hard to be "in series with" the other. And if we take
"feed point" to be "feedpoint," then since the two seem to be
the same, it's hard to admit that they're in series. But I'm sure
you can clear this up for me. Can you just write down the
equations? (with all the symbols defined -- that'll make it
much clearer).

Rr + r = r feedpoint.
See above.


5. Do you know that the same amount of current that flows at the feed
point of the antenna is the same amount that flows in the radiation
resistance of the antenna? They are in series you know.

"Flows in the radiation resistance?" I don't honestly know whether
Larry knows more or less than you do, but at least I've never seen him
write something like this.

Me either that's why I ask the question. But first you must understand
what radiation resistance is. See above.


6. I assume that you know ohms law and that if the same amount of
current flows in two series resistors that the larger resistance will
dissipate more power than the lower value resistor?

Um...Ohm's law tells me, if I recall correctly, that for certain
materials, the current flowing through them varies linearly with the
applied (DC) voltage; in these cases, the ratio of the two is called
the "resistance." If you think I'm being overly pedantic here, you can
ask "what's the resistance of a diode?" The answer is, of course,
"the current through a diode does not vary linearly as a function
of the applied voltage, so it does not have a resistance."
So you have to be careful about applying Ohm's law...

Oh the diode has resistance all right but in its case you have to
define what point on the curve you are looking at. Irrelevant here
though. Here we are talking about two linear resistors. Nothing
complicated.


7. Do you understand that there is a phase shift between current and
voltage across a coil in an AC circuit.

I would say "an inductor has a complex impedance that happens not to
be a real number, but rather one that has an imaginary part as well."

Also true. But it also has a real phase shift. All part of
understanding why there is high voltage across the loading coil.


8. Do you understand that the radiation resistance gets very low in a
short antenna?

Uh...I guess I don't "understand" that. But if you'd write
out an equation or two, I might know what you meant by it.

Rr = 395 x (h/lambda) squared

Where Rr = radiation resistance
h = radiator height in meters
lambda = wavelength in meters

(referenced from the ARRL antenna handbook) like it or not. :)


----------------------------------------------------------

Someone else asked a very interesting question earlier:

1. You state that some editions of some ARRL publication are wrong.
2. You state that other editions are right.

You haven't told us where one finds evidence for this
wrongness/correctness. Does one of them have an error in some
equation? Can you construct a real circuit for which the
predictions of one book are wrong and the predictions of the
other are correct? Or do we just have to take your word
for it that one is right, the other wrong? If it's the
latter, then why bring the ARRL into it? Why don't we just
agree that whatever you say is right, and whatever anyone
says that appears to contradict it is wrong? It'd save a lot
of writing...

I am not going to say it again. Please READ the former posts. I have
shown the references many times and explained what the errors were.
And please, don't take my word for it if you have any doubts.


statement about antennas paraphrasing ARRL ahndbook deleted

Here I provided a reference and you don't want to consider it?
But yet you ask for references.

Isn't that amazing! Must be black magic huh Larry? Or just maybe it
has something to do with the above questions.

Maybe...but I'd find it more compelling if it had something to
do with known (by which I mean "widely accepted and tested")
physical laws like Maxwell's equations, and an analysis of
the circuits in question.

If you are really interested in learning please read the original post
in this thread and go look at the web site of W8JI that I posted
there. He explains this very subject very well in detail. He even
throws in a little math for you.

Regards
Gary


--John Hughes