Here is the scenario:

Hamshack on the west side of the house.

OCF dipole between two trees running perpendicular over the house with
the Balun directly above the shack (now *that* is handy)

Butternut vertical on the east side of the house. 12 radials so far.

Now here is what brings about the question. Over the winter months, I
had to have my sewer line to the street replaced, which ended up making
a huge mess out of my front yard. This means that I will probably end up
tilling and replanting a large part of the yard.

Is there any point to laying radials in the front yard? They would be
quite a ways (~50 feet) from the radials around the Butternut.

The main reason I ask though, is that I thought I heard here some time
ago, that a dipole would perform better over a good ground system.

- Mike KB3EIA -

I queried a real old timer locally about pretty much the same thing...
He said that would give me consistant radiation patterns, despite the ground
drying out during the summer.
Regardless, it certianly would not hurt!
"Mike Coslo" wrote in message
...
Here is the scenario:

Hamshack on the west side of the house.

OCF dipole between two trees running perpendicular over the house with the
Balun directly above the shack (now *that* is handy)

Butternut vertical on the east side of the house. 12 radials so far.

Now here is what brings about the question. Over the winter months, I had
to have my sewer line to the street replaced, which ended up making a huge
mess out of my front yard. This means that I will probably end up tilling
and replanting a large part of the yard.

Is there any point to laying radials in the front yard? They would be
quite a ways (~50 feet) from the radials around the Butternut.

The main reason I ask though, is that I thought I heard here some time
ago, that a dipole would perform better over a good ground system.

- Mike KB3EIA -

denton wrote:

I queried a real old timer locally about pretty much the same thing...
He said that would give me consistant radiation patterns, despite the ground
drying out during the summer.
Regardless, it certianly would not hurt!

Well at least I'm not the only one that had the same - possibly odd
question!

- Mike KB3EIA

I also wonder about 'good grounds' for dipoles.
If your terrain was very sandy - so much so that it would take over a
hundred ft of
ground rod to make a difference - then would this mean that your antenna
would
perform as though it was 100 ft higher - than over "normal" ground. ???

I've seen industrial plants use "ungrounded 480volt delta" system, and
with this system, if
any of the 480 v legs come into contact with "ground" (say a wet piece of
concrete floor)
there would be no sparks - as that corner would become the grounded leg.



"Mike Coslo" wrote in message
...
Here is the scenario:

Hamshack on the west side of the house.

OCF dipole between two trees running perpendicular over the house with
the Balun directly above the shack (now *that* is handy)

Butternut vertical on the east side of the house. 12 radials so far.

Now here is what brings about the question. Over the winter months, I
had to have my sewer line to the street replaced, which ended up making
a huge mess out of my front yard. This means that I will probably end up
tilling and replanting a large part of the yard.

Is there any point to laying radials in the front yard? They would be
quite a ways (~50 feet) from the radials around the Butternut.

The main reason I ask though, is that I thought I heard here some time
ago, that a dipole would perform better over a good ground system.

- Mike KB3EIA -

"Hal Rosser" wrote

I also wonder about 'good grounds' for dipoles.
If your terrain was very sandy - so much so that it would take over a
hundred ft of
ground rod to make a difference - then would this mean that your antenna
would
perform as though it was 100 ft higher - than over "normal" ground. ???

I've seen industrial plants use "ungrounded 480volt delta" system, and
with this system, if
any of the 480 v legs come into contact with "ground" (say a wet piece of
concrete floor)
there would be no sparks - as that corner would become the grounded leg.

You might be mixing dc-theory with rf, and looking for a particular
relationship that's not there. The antenna is not 100' higher electrically
as you suggest. In terms of your 100' ground rod, just because it might take
that deep a hole to achieve say, 5 ohms dc-resistance, that does not make
the surface or an antenna above it at an elevated potential with respect to
each other.

A dipole certainly behaves differently over varying resistances of soils.
But the efficiency differences have never been equivalent to the antenna
being at a different elevation because of soil conditions. Now maybe I get
away with less ground loss from a half-wave dipole that is not quite a
half-wave above ground, because my soil is very sandy, is that what you
meant? It doesn't change the electrical height of my antenna any, but the
soil is such a lousy conductor that less is absorbed by a slightly too-low
antenna.

Jack

Sounds like your defining exactly what happens if you raise the antenna...

"Jack Painter" wrote in message
news:lQYbe.241$qV3.90@lakeread04...
.......Snip......
But the efficiency differences have never been equivalent to the antenna
being at a different elevation because of soil conditions. Now maybe I get
away with less ground loss from a half-wave dipole that is not quite a
half-wave above ground, because my soil is very sandy, is that what you
meant? It doesn't change the electrical height of my antenna any, but the
soil is such a lousy conductor that less is absorbed by a slightly too-low
antenna.

Jack

You might be mixing dc-theory with rf, and looking for a particular
relationship that's not there. The antenna is not 100' higher electrically
as you suggest. In terms of your 100' ground rod, just because it might
take
that deep a hole to achieve say, 5 ohms dc-resistance, that does not make
the surface or an antenna above it at an elevated potential with respect
to
each other.

A dipole certainly behaves differently over varying resistances of soils.
But the efficiency differences have never been equivalent to the antenna
being at a different elevation because of soil conditions. Now maybe I get
away with less ground loss from a half-wave dipole that is not quite a
half-wave above ground, because my soil is very sandy, is that what you
meant? It doesn't change the electrical height of my antenna any, but the
soil is such a lousy conductor that less is absorbed by a slightly too-low
antenna.

Jack

You're probably right - but then why does the operator on the hill get
better recption than the one in the valley.
if sand is an insulator, then being on top of a 100-ft pile of sand would be
like at the topp of a glass tower, right?
why not?

"Hal Rosser" wrote

You might be mixing dc-theory with rf, and looking for a particular
relationship that's not there. The antenna is not 100' higher
electrically
as you suggest. In terms of your 100' ground rod, just because it might
take
that deep a hole to achieve say, 5 ohms dc-resistance, that does not
make
the surface or an antenna above it at an elevated potential with respect
to
each other.

A dipole certainly behaves differently over varying resistances of
soils.
But the efficiency differences have never been equivalent to the antenna
being at a different elevation because of soil conditions. Now maybe I
get
away with less ground loss from a half-wave dipole that is not quite a
half-wave above ground, because my soil is very sandy, is that what you
meant? It doesn't change the electrical height of my antenna any, but
the
soil is such a lousy conductor that less is absorbed by a slightly
too-low
antenna.

Jack

You're probably right - but then why does the operator on the hill get
better recption than the one in the valley.
if sand is an insulator, then being on top of a 100-ft pile of sand would
be
like at the topp of a glass tower, right?
why not?


Well, the irony of which Fred (W4IJE) replied surely applies - it seems to
have the same effect as "raising the antenna", which I did also admit. So
the only point I struggled to make was it is not electrically higher. Height
of an antenna surely helps us in all cases, and part of that is related to a
dipoles most efficient design height above ground, part is because we clear
interfering objects in the near and far fields when we "elevate" ;-)

I wouldn't stand on a tall sand hill in a thunderstorm, lightning would sure
be happy to race through you and down the side of the sand pile on its way
to a more conductive earthing! But a dipole erected 1/4 - 1/2 wave above the
same tall sand pile should be quite happy - especially if the Atlantic Ocean
was on one side, the Chesapeake Bay on another, and inland waters on a third
side. That pretty much describes the "hill" off the beach that I live on.

73,

Jack
Virginia Beach

"Mike Coslo" wrote in message
...
Here is the scenario:

Hamshack on the west side of the house.

OCF dipole between two trees running perpendicular over the house
with
the Balun directly above the shack (now *that* is handy)

Butternut vertical on the east side of the house. 12 radials so far.

Now here is what brings about the question. Over the winter months,
I
had to have my sewer line to the street replaced, which ended up
making
a huge mess out of my front yard. This means that I will probably
end up
tilling and replanting a large part of the yard.

Is there any point to laying radials in the front yard? They would
be
quite a ways (~50 feet) from the radials around the Butternut.

The main reason I ask though, is that I thought I heard here some
time
ago, that a dipole would perform better over a good ground system.

- Mike KB3EIA -

=============================

No point in laying radials. Too far away from the Butternut. Current
does not flow that far along buried wires. Attenuation along the wire
is too great.
----
Reg.

Mike, KB3EIA wrote:
"The main reason I ask, is that I thought I heard here some time ago,
that a dipole would perform better over a good ground system."

It may not.

At a distant point, the received signal is probably composed of two
parts that started their journey as an incident ray and a ray which was
the incident ray`s reflection off on a tangent from the surface of the
earth.

If by good fortune these two rays happened to arrive at the distant
receiving point in-phase they would present a stronger signal than the
direct ray alone, and certainly a stronger signal than a combination of
two out-of-phase signals.

Unfortunately, the incident wave`s reflection is always out-of-phase
with the incident wave which produces it at the reflection point. A
perfect reflector would ensure the reflection was equal in magnitude as
well as out-of-phase to the incident ray.

Unless you get a difference in path length between incident and
reflected rays to invert the phase of one of the rays as compared with
the other, they will tend to cancel. You might be better off without the
reflected ray.

The ground connection in a vertical antenna system is entirely
different. Half the antenna system is the antenna`s image in the earth.
The connection to the earth or to a capacitive coupling to the earth
(elevated radials or ground-plane) carries the r-f current to the earth
side of the system. Any resistance in your gtound system directly adds
to loss in the system.With the usual vertical antenna system, radials
are essential.for efficiency..

This was a long-winded way to say you don`t need radials with a
horizontal dipole for r-f efficiengy. You do need a ground connection
for electrical safety and lightning protection. Radials work well for
these too.

Best regards, Richard Harrison, KB5WZI