Brown, Lewis & Epstein
 

There has been considerable discussion on the antenna news group
regarding ground systems for monopole antennas. Invariably, a
reference is made to a study prepared by Brown, Lewis, and Epstien
that was published in the proceedings of the IRE in 1937.
Unfortunately, many amateurs do not live near a major library or
university where they would be able to obtain a copy of this paper.

Therefore, I have placed on my web site a scanned copy of "Ground
Systems As A Factor In Antenna Efficiency" by G.H. Brown, R.F. Lewis
and J. Epstein which was publish by Institute of Radio Engineers in
June 1937. This scanned copy is identical in format as a copy I
obtained from the library.

Be advised that you need Adobe Reader for viewing. Additionally, this
is a rather large file (about 3MB).

You may view this document at:

http://users.adelphia.net/~k6mhe/BLE.html

73,
Danny, K6MHE

Thank you Sir!

"Dan Richardson arrl net" k6mheatdot wrote in message
...
There has been considerable discussion on the antenna news group
regarding ground systems for monopole antennas.

Thank you, Thank you, Thank you.

Charlie

Dan:

I cannot thank you enough for taking the time to scan and post this
article. It is almost impossible to find articles that old that are
still legible. This is an example of the spirit of HAM radio.

Have a great 4th of July holiday.

73, Lew

(I have tried unsuccessfully to make the tabular data in the msg below come out
correctly. I apologize for that and hope you can interpret the data
successfully. Walt,W2DU)

Thanks to Richard Harrison, he has supplied us with the renowned Brown, Lewis
and Epstein paper, reporting the voluminous and enlightening experimental data
concerning the length and number of ground radials required in approaching the
condition of perfect ground underneath a vertical radiator. This paper has long
been well known and highly respected in the communications engineering
community, and since 1938 has become the standard for engineering the radial
systems for AM BC stations Worldwide. The FCC requirement for radials in US BC
stations is based on data in the BLE paper.

The tragedy here is that BLE paper has gone practically unknown in the amateur
community, as witnessed by so many continual questions and incorrect answers
concerning the length and number of radials required to achieve the desired
performance of our vertical radiators.

So let me present a short, but definitive abstract of the pertinent numbers
taken from the paper, that answer some of the pertinent questions correctly.

As a reference on which to base the radiated field strength, the industry
standard has traditionally used millivolts per meter to describe field strength.
Specifically, the field strength of 194.5 millivolts per meter at one mile,
radiated from a quarter-wavelength radiator over perfect ground with 1000 watts
input, is the industry standard. In other words, this field strength is the
maximum attainable under ideal conditions. The data below, obtained directly
from measurements made at 3 MHz by Brown, Lewis and Epstein in 1937, provide
definitive answers to those who ask how many radials of what length are
necessary to provide a suitable ground plane. When comparing the fields
strengths below, remember that 194.5 mv/meter is the field strength obtained
with perfect lossless ground.

Number of Field Strength Loss in dB Relative

Radials in mv/meter to Perfect Ground

Length Length

0.4 wl 1/4 wl 1/8 wl 0.4 wl 1/4 wl 1/8 wl

113 192 180 152 0.112 0.673 2.14

60 185 176 150 0.435 0.868 2.26

30 174 162 150 0.967 1.59 2.26

15 158 153 1.81 2.08

2 126 120 118 3.77 4.19 4.39

When reviewing these data, please keep in mind that as the field strength
approaches 194.5 mv/meter the effective ground is approaching perfect ground,
which means that the conductivity of the ground in which the radials are planted
is irrelevant, only the ground external to the radial system is relevant with
respect to conductivity.

It should also be kept in mind that the energy in the EM fields surrounding the
vertical radiator diminishes with distance from the radiator. Thus the
displacement currents entering the ground diminish proportionately with
distance. Consequently, there is a distance from the radiator after which the
currents become too small to be significant to the conservation of power
radiated. This fact determines the maximum length of the radials necessary to
reach the point where the law of diminishing returns prevails. The measurements
reported in the BLE paper show this distance to be between 0.4 and 0.5
wavelengths. As noted above, this distance is relative to the amount of energy
in the displacement currents at this distance from the radiator, and is in no
way relevant to any resonant length of the radial. It is well known that radials
buried in the ground lose all sense of resonance.

Walt, W2DU

Man, O, Man, do I have some apologizing to do to Danny Richardson, K6JHE. Danny
is the one who supplied the data on the Brown, Lewis and Epstein paper, not
Richard Harrison.

I'm sorry, Danny, it was a senior moment at age 86 that's responsible.

Walt, W2DU

Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?

"Walter Maxwell" wrote in message
...
(I have tried unsuccessfully to make the tabular data in the msg below
come out

"Fred W4JLE" wrote in message
...
Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?

Well, Fred, it's because it has everything to do with how much of your xmtr
power is heating the ground vs how much is being radiated at whatever frequency
you're using. We're not even talking about ground wave, it's how much power is
radiated, period.

Walt

"Fred W4JLE" wrote in message
...
Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?

Well, Fred, it's because it has everything to do with how much of your xmtr
power is heating the ground vs how much is being radiated at whatever frequency
you're using. We're not even talking about ground wave, it's how much power is
radiated, period.

Walt

"Fred W4JLE" wrote in message
...
Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?

Well, Fred, it's because it has everything to do with how much of your xmtr
power is heating the ground vs how much is being radiated at whatever frequency
you're using. We're not even talking about ground wave, it's how much power is
radiated, period.

Walt

"Fred W4JLE" wrote in message
...
Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?

Well, Fred, it's because it has everything to do with how much of your xmtr
power is heating the ground vs how much is being radiated at whatever frequency
you're using. We're not even talking about ground wave, it's how much power is
radiated, period.

Walt

On Fri, 1 Jul 2005 16:57:19 -0400, "Walter Maxwell"
wrote:

Man, O, Man, do I have some apologizing to do to Danny Richardson, K6JHE. Danny
is the one who supplied the data on the Brown, Lewis and Epstein paper, not
Richard Harrison.

I'm sorry, Danny, it was a senior moment at age 86 that's responsible.

Walt, W2DU

Not a problem Walt. Now had I never made any errors............ G

Very 73 my friend,

Danny,
K6MHE

On Fri, 1 Jul 2005 17:12:44 -0400, "Fred W4JLE"
wrote:

Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?

I think you may have miss the point Fred... Its about antenna
efficiency.

Danny,
K6MHE

"Walter Maxwell" wrote in message
...
Man, O, Man, do I have some apologizing to do to Danny Richardson, K6JHE.
Danny is the one who supplied the data on the Brown, Lewis and Epstein paper,
not Richard Harrison.

I'm sorry, Danny, it was a senior moment at age 86 that's responsible.

Walt, W2DU

Dang, I can't seem to get anything right today. Can't even spell Danny's call
sign correctly. Repeat after me, it's K6MHE, it's K6MHE, it's K6MHE.

Walt, W2DU

Sorry about the multiple postings above. My moronic computer told me each time
that the msg could not be sent, so I kept trying.

Walt, W2DU

Maybe this will help clarify it. . .

As Walt and Danny said, this is all about efficiency -- the fraction of
your applied power that gets used heating the ground. So the ground wave
and sky wave are reduced by the same fraction. Just look at those dB
values in the right hand column of Walt's summary, and they'll apply to
75 meter sky wave as well as to ground wave.

They won't be exact, of course, since they depend on both ground
characteristics (to quite a fair depth) and frequency. But they're as
good a set of working values as you'll find.

Roy Lewallen, W7EL

Dan Richardson k6mheatarrl wrote:
On Fri, 1 Jul 2005 17:12:44 -0400, "Fred W4JLE"
wrote:


Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?


I think you may have miss the point Fred... Its about antenna
efficiency.

Danny,
K6MHE

"Walter Maxwell" wrote:
When reviewing these data, please keep in mind that as the field strength
approaches 194.5 mv/meter the effective ground is approaching perfect
ground, which means that the conductivity of the ground in which the
radials are planted is irrelevant, only the ground external to the radial
system is relevant with respect to conductivity.

BL&E measured the groundwave field strength generated by a 200 milliwatt
carrier 0.3 miles from a vertical radiator. This value was converted to
equivalent field for 1 kW of radiated power at a distance of 1 mile. With
this technique, and with 113 each 0.412-wave radials, they found that their
measured/converted field was less than 0.1124 dB below the theoretical value
for it over a perfect ground plane. These results demonstrate that the
consideration of ground conductivity during this study over this short path
was unnecessary (REG, please note).

It should also be kept in mind that the energy in the EM fields
surrounding the vertical radiator diminishes with distance from the
radiator. Thus the displacement currents entering the ground diminish
proportionately with distance. Consequently, there is a distance from the
radiator after which the currents become too small to be significant to
the conservation of power radiated. This fact determines the maximum
length of the radials necessary to reach the point where the law of
diminishing returns prevails. The measurements reported in the BLE paper
show this distance to be between 0.4 and 0.5 wavelengths.

And that was for 113 radials. If only a few radials are used, BL&E report
that it is pointless to extend them that far.

RF

"Richard Fry" wrote in message
...
"Walter Maxwell" wrote:
When reviewing these data, please keep in mind that as the field strength
approaches 194.5 mv/meter the effective ground is approaching perfect ground,
which means that the conductivity of the ground in which the radials are
planted is irrelevant, only the ground external to the radial system is
relevant with respect to conductivity.

BL&E measured the groundwave field strength generated by a 200 milliwatt
carrier 0.3 miles from a vertical radiator. This value was converted to
equivalent field for 1 kW of radiated power at a distance of 1 mile. With
this technique, and with 113 each 0.412-wave radials, they found that their
measured/converted field was less than 0.1124 dB below the theoretical value
for it over a perfect ground plane. These results demonstrate that the
consideration of ground conductivity during this study over this short path
was unnecessary (REG, please note).

It should also be kept in mind that the energy in the EM fields surrounding
the vertical radiator diminishes with distance from the radiator. Thus the
displacement currents entering the ground diminish proportionately with
distance. Consequently, there is a distance from the radiator after which the
currents become too small to be significant to the conservation of power
radiated. This fact determines the maximum length of the radials necessary to
reach the point where the law of diminishing returns prevails. The
measurements reported in the BLE paper show this distance to be between 0.4
and 0.5 wavelengths.

And that was for 113 radials. If only a few radials are used, BL&E report
that it is pointless to extend them that far.

RF

Correct on both counts, Richard, thanks for reminding Reg, I forgot to. Did I
mention that I had the privilege of working at Brown's RCA antenna lab along
side Epstein for several years? Bob Lewis had left RCA when I arrived, but I
knew him later as a ham, W2EBS.

Walt, W2DU

So as I understand it, as I add more radials, my field strength should
increase regardless of the elevation angle. Assuming I make all measurements
at the same point.


"Walter Maxwell" wrote in message
...

"Fred W4JLE" wrote in message
...
Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who
don't
care about groundwave?

Well, Fred, it's because it has everything to do with how much of your
xmtr
power is heating the ground vs how much is being radiated at whatever
frequency
you're using. We're not even talking about ground wave, it's how much
power is
radiated, period.

Walt

"Walter Maxwell"
Correct on both counts, Richard, thanks for reminding Reg, I forgot to.
Did I mention that I had the privilege of working at Brown's RCA antenna
lab along side Epstein for several years? Bob Lewis had left RCA when I
arrived, but I knew him later as a ham, W2EBS.
_______________

That would have been a privilege. When with RCA I worked a bit with Matti
Siukola, Oded Ben-Dov, Nick Nikolayuk and others at the RCA broadcast
antenna design center and test range at Gibbsboro, NJ . Great facility in
those days.

RF

"Fred W4JLE" wrote in message
...
So as I understand it, as I add more radials, my field strength should
increase regardless of the elevation angle. Assuming I make all measurements
at the same point.


"Walter Maxwell" wrote in message
...

"Fred W4JLE" wrote in message
...
Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who
don't
care about groundwave?

Well, Fred, it's because it has everything to do with how much of your
xmtr
power is heating the ground vs how much is being radiated at whatever
frequency
you're using. We're not even talking about ground wave, it's how much
power is
radiated, period.

Walt

Fred, the radials affect only the efficiency of the radiator--power lost in the
ground resistance vs power radiated. The take off, or elevation angle is
determined by the ground conductivity external to the radial system, the poorer
the ground the less power will radiate at low elevation angles. In other words,
the better the ground conductivity external to the radial system the lower the
elevation angle of the maximum radiation. If the conductivity was perfect at an
infinite distance away from the radiator the elevation angle of the maximum
radiation lobe would be zero degrees.

Walt, W2DU

"Richard Fry" wrote in message
...
"Walter Maxwell"
Correct on both counts, Richard, thanks for reminding Reg, I forgot to. Did I
mention that I had the privilege of working at Brown's RCA antenna lab along
side Epstein for several years? Bob Lewis had left RCA when I arrived, but I
knew him later as a ham, W2EBS.
_______________

That would have been a privilege. When with RCA I worked a bit with Matti
Siukola, Oded Ben-Dov, Nick Nikolayuk and others at the RCA broadcast antenna
design center and test range at Gibbsboro, NJ . Great facility in those days.

RF
______________

Very interesting, Richard, of all the years I've been on this NG you are the
first RCA person I've met on the NG. What years were you with RCA?

While at the RCA Princeton Labs I also worked with O.M. (Woody) Woodward, Bruce
Rankin, and Don Peterson. Perhaps you knew them. I joined RCA in 1949,
transferred to the antenna lab in 1957, and later originated the antenna lab at
the then new Astro-Electronics Division in Hightstown. Was located there until I
retired to DeLand, Florida in 1980. While at Princeton I developed the entire
antenna system for TIROS 1, the World's first weather satellite.

I never had the pleasure of meeting any of the guys at Gibbsboro, but the names
of Matti and Oded came up quite often. I heard Woody and Jess Epstein talking
with them on the phone quite frequently.

I also spent some time at Cherry Hill as part of a three-man team developing the
3.6 GHz dish used on Lunar Rover, the moon buggy. I performed all the final
impedance and antenna pattern measurements on the three dishes prior to delivery
to NASA.

Perhaps we can meet some day and discuss our experiences at RCA. I consider
myself fortunate to have been there during the early days of space exploration,
they were truly exciting days.

Walt, W2DU

Walter Maxwell wrote:
Very interesting, Richard, of all the years I've been on this NG you are the
first RCA person I've met on the NG.

But Walt, I was once W6RCA. :-)
--
73, Cecil http://www.qsl.net/w5dxp


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"Walter Maxwell" wrote:
Very interesting, Richard, of all the years I've been on this NG you are
the first RCA person I've met on the NG. What years were you with RCA?

1965-1980. My position certainly was not as exalted as that of
Epstein/Lewis/Siukola/Maxwell/et al, but I was fortunate enough to work with
Siukola and Ben-Dov of Gibbsboro in developing and proving RCA's RF Pulse
test equipment system used to evaluate and optimize broadcast TV antenna
systems. This test system may be thought of as a "narrow-band TDR," in that
it duplicates the spectrum of the standard TV signal, rather than using a
bandwidth of maybe 100X that of the TV channel. Excess test bandwidth gives
high pulse returns outside the TV channel -- which are valid, but
unimportant to the performance of the antenna system.

RF

"Cecil Moore" wrote in message
...
Walter Maxwell wrote:
Very interesting, Richard, of all the years I've been on this NG you are the
first RCA person I've met on the NG.

But Walt, I was once W6RCA. :-)
--
73, Cecil http://www.qsl.net/w5dxp

'ya know, Cecil, yer right, how could I have overlooked you. In fact, I've
always wondered why you gave up that illustrious call sign.

Walt, W2DU

Since the name of Dr. George H. Brown, of Brown, Lewis and Epstein is not well
known in the amateur community, I would like to acquaint you with some of his
other accomplishments that are well known in the engineering community,
especially in the AM-FM-TV broadcast community. His name deserves attention in
the amateur community as well.



In addition to his work that established the ground radial standards for AM
broadcasting, he discovered the reason the early diamond-shaped tower radiators
produced undesirable radiation characteristics, and proved experimentally that
towers of uniform cross section solved the problem. As a result of his
experimental proof, the FCC denied further use of the diamond shape tower, and
has since required all AM BC antenna towers be of uniform cross section. He also
developed sectionalized radiators for control of the elevation pattern.



He invented the ground-plane antenna for VHF/UHF use. He found that two radials
were sufficient, but marketing people convinced him that the antennas would sell
better with four.



With his famous 1937 paper, 'Directional Antennas' he established the basis for
directional arrays used in thousands of AM broadcast stations.



He worked closely with John Kraus in the early days, and showed Kraus the
importance of close spacing of elements in an array to increase the gain over
that obtained with quarter-wave spacing. The result was Kraus' close spaced beam
known as the 'W8JK' beam. Kraus gave this credit to Brown in his book,
"Antennas."



He developed a method for RF heating, especially for the joining, or 'sewing' of
plastic sheet material, a method that led to the development of microwave ovens.



As lead engineer in RCA's color television lab at the RCA Laboratories in
Princeton, he successfully led the development of the present system color
system used in all US tv operations, the NTSC system that permitted black and
white receivers to see color transmissions in black and white, overturning the
original FCC acceptance of the CBS spinning wheel system that would not permit
black and white receivers to receive color transmissions.



George Brown retired as an Executive Vice President of RCA.



These are just a few of his noteworthy accomplishments as an extraordinary
engineer.



Walt, W2DU

On Sat, 2 Jul 2005 10:03:11 -0400, "Walter Maxwell"
wrote:

These are just a few of his noteworthy accomplishments as an extraordinary
engineer.

Yes Walter, luckily I have a copy of his autobiography "and part of
which I was" publish in the early 1980s. He surely had a full and
fruitful life.

Danny, K6MHE

Walter Maxwell wrote:
'ya know, Cecil, yer right, how could I have overlooked you. In fact, I've
always wondered why you gave up that illustrious call sign.

A land of fruits and nuts call didn't fit very well in
Texas, :-) just kidding. I was first licensed as WN5DXP
in 1952 and just couldn't resist getting my old call
back when I moved back to the same land as I lived
on then, land homesteaded by my grandfather before
the 20th century.
--
73, Cecil http://www.qsl.net/w5dxp


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On Thu, 30 Jun 2005 05:32:33 -0700, Dan Richardson
k6mheatarrldotnet wrote:



Therefore, I have placed on my web site a scanned copy of "Ground
Systems As A Factor In Antenna Efficiency" by G.H. Brown, R.F. Lewis
and J. Epstein which was publish by Institute of Radio Engineers in
June 1937. This scanned copy is identical in format as a copy I
obtained from the library.

I downloaded your PDF file and burned it to a disk. Very interesting
paper -- I can even understand much of it (I ain't no engineer) --
Intrigued by the picture of the "plow" they used to lay miles and
miles of radials -- wish I had one.

bob
k5qwg



Be advised that you need Adobe Reader for viewing. Additionally, this
is a rather large file (about 3MB).

You may view this document at:

http://users.adelphia.net/~k6mhe/BLE.html

73,
Danny, K6MHE