I'm thinking of buying a used Hustler 6BTV vertical ( 80 thru 10
coverage) and was wondering about how many radials I'd need and how
long they should be ? If I do get it, I'd be ground mounting the
vertical and planting the radials about 1 - 2 inches deep in soil
that's mainly clay.

Thanks in advance.

73 Gary

"Gary" wrote in message
...
I'm thinking of buying a used Hustler 6BTV vertical ( 80 thru 10
coverage) and was wondering about how many radials I'd need and how
long they should be ? If I do get it, I'd be ground mounting the
vertical and planting the radials about 1 - 2 inches deep in soil
that's mainly clay.

Thanks in advance.

73 Gary

You might want to think about hardware cloth - - half inch screen dipped in
zinc - - virtually one continuous sheet, solderable and resistant to weather
and moisture. It comes in a 36" width, and I bought about 100 ft of it for
my ground-mounted 6-band Butternut. The results have been excellent. People
use cars and trailers for their counterpoise - - but this makes a much
bigger one, with a lot more capacitance to ground. You can then sod over it
or put in plastic sheeting and pebbles - - whatever you like. The only thing
you need to settle is to get your sprinklers arranged ahead of time so you
don't have to trench through under the hardware cloth.

73, Chuck W6PKP

On Wed, 29 Jun 2005 18:27:54 -0700, "Chuck Olson"
wrote:


"Gary" wrote in message
.. .
I'm thinking of buying a used Hustler 6BTV vertical ( 80 thru 10
coverage) and was wondering about how many radials I'd need and how
long they should be ? If I do get it, I'd be ground mounting the
vertical and planting the radials about 1 - 2 inches deep in soil
that's mainly clay.

Thanks in advance.

73 Gary

You might want to think about hardware cloth - - half inch screen dipped in
zinc - - virtually one continuous sheet, solderable and resistant to weather
and moisture. It comes in a 36" width, and I bought about 100 ft of it for
my ground-mounted 6-band Butternut. The results have been excellent. People
use cars and trailers for their counterpoise - - but this makes a much
bigger one, with a lot more capacitance to ground. You can then sod over it
or put in plastic sheeting and pebbles - - whatever you like. The only thing
you need to settle is to get your sprinklers arranged ahead of time so you
don't have to trench through under the hardware cloth.

73, Chuck W6PKP


Ok, thanks Chuck ... 73 Gary K8IQ

Gary,
The general 'generic' answer is as many as you can stand to
put in, and as long as you can make them. Usually, the length is a 1/4
wave (or sort of close) for the lowest frequency of use. Don't have
that much room? Then make them as long as possible. The more you put
down the 'better' it'll be. That's where the 'as many as you can stand'
comes in. At some point you'll be ready to quit, so quit...
'Doc

PS - The 'text book' answer? Not really, but probably the average one.

On Thu, 30 Jun 2005 03:37:48 GMT, 'Doc wrote:

Gary,
The general 'generic' answer is as many as you can stand to
put in, and as long as you can make them. Usually, the length is a 1/4
wave (or sort of close) for the lowest frequency of use. Don't have
that much room? Then make them as long as possible. The more you put
down the 'better' it'll be. That's where the 'as many as you can stand'
comes in. At some point you'll be ready to quit, so quit...
'Doc

PS - The 'text book' answer? Not really, but probably the average one.

Thanks Doc ! .... 73 Gary K8IQ

Here is an additional question.

I have to mount my 40/80 vertical in a place where it can be hidden by
trees, which means against the back fence in my yard. I can only put
radials to cover 180 degrees. I assume my signal will radiate best in that
direction. What kind of radiation will I get toward the side of the antenna
without the radials?

Mark, KJ7BS

RF
"Mark" wrote in message
news:Cs0xe.14415$ro.8260@fed1read02...
Here is an additional question.

I have to mount my 40/80 vertical in a place where it can be hidden by
trees, which means against the back fence in my yard. I can only put
radials to cover 180 degrees. I assume my signal will radiate best in
that
direction. What kind of radiation will I get toward the side of the
antenna
without the radials?

Mark, KJ7BS

Mark,

This month's edition of QEX (July/Aug. 2005) has an article
addressing your question with a simulation matching your
question exactly. Bottom line: put as many radials as long as
possible in your yard and don't worry about it. The simulation
with 60 1/4 wavelength radials in a 180 degree arc only resulted
in a 1.67dB difference in signal strengths from the radial
direction to the no radial direction.

73,
Larry, W0QE

Mark wrote:
Here is an additional question.

I have to mount my 40/80 vertical in a place where it can be hidden by
trees, which means against the back fence in my yard. I can only put
radials to cover 180 degrees. I assume my signal will radiate best in that
direction. What kind of radiation will I get toward the side of the antenna
without the radials?

Mark, KJ7BS

I have read Al Christman's QEX article, and though he mentions radial systems
used in AM BC stations, I doubt if he's read Brown, Lewis and Epstein, else I
also doubt if he would have made some of the statements that appear in the
article



The Brown, Lewis and Epstein paper is a must read for anyone contemplating the
installation of radials for a vertical radiator. Fortunately, Richard Harrison
has supplied the paper in the thread below 'Brown Lewis and Epstein'.



My post below has also been added to the above mentioned thread. However, I
apologize for the problem in making the tabular data come out right--I tried,
but was unsuccessful, so I hope you can interpret the data to be useful to you.
Now to the mail I posted in the above mentioned thread. 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