What is RF ground?
 

What would you define RF ground as? There seem to be a lot of different
ideas.

What is RF ground?
 

"David" nospam@nospam wrote in :

What would you define RF ground as? There seem to be a lot of different
ideas.

Except in the case of ground-mounted antennas, there is really no such
thing. There is RF neutral, though.


--
Dave Oldridge+
ICQ 1800667

What is RF ground?
 

"David" wrote
What would you define RF ground as? There seem to be
a lot of different ideas.
______________

A good "r-f ground" has a very small impedance to the flow of r-f current at
the frequency of interest.

A good r-f ground is especially important when using a ground-mounted
vertical monopole radiator, because the path to "ground" is in series with
the r-f current flowing on the monopole. Power consumed by the ground
system is wasted (not radiated as EM energy).

At medium wave broadcast frequencies and in the 160 meter and low HF bands,
a system of ~120 buried radials each about 1/4-wave long provides a
reasonably low-Z ground connection -- probably 2 ohms or less, regardless of
the ground conductivity at the site. This was determined experimentally by
Brown, Lewis and Epstein of RCA in 1937.

Copper water pipes in the home, and even buried ground rods typically are
not good, low-Z r-f grounds.

But many antenna types - such as a dipole - do not need or use such an r-f
ground for efficient radiation.

RF

What is RF ground?
 

"David" nospam@nospam wrote in message
...
What would you define RF ground as? There seem to be a lot of different
ideas.


1. One needs to define properties or "regular" ground.

2. Illuminate it with RF of particular frequency and particular antenna.

3. Study the effect of 1 on 2 and you will get some idea. Amount of
reflection or absorption would be the indicator of how good "RF ground" it
is.

As far as suitability of "ground" to "work" with antennas it is somewhere
from horrible (rocky ground) to "perfect" (sea water, copper mine, etc.)

Other than that, if you can walk or swim on/in it and you expose it to RF,
then I suppose you could call it RF ground.
If there is no RF, the RF ground disappears :-)

Somethinglikethat?!?

73 Yuri, K3BU
da salt water muddy RF ground lover
join the Tesla Sparks at N2EE www.TeslaRadio.org

What is RF ground?
 

rf ground is where ever you connect your meter/scope/analyzer ground lead.

"David" nospam@nospam wrote in message
...
What would you define RF ground as? There seem to be a lot of different
ideas.

What is RF ground?
 

David wrote:
What would you define RF ground as? There seem to be a lot of different
ideas.



David:

Ground can be a relative thing. What I have always found to be good
advice is that EVERY ground, at some point, be allowed to reach a low
ohmic earth ground (best possible if it all occurs at the exact same
earth ground point--or no current flows and there is no voltage
potential between such grounds.) For example, although a dipole needs
no rf ground directly at the point it connects to the feed-line, the rig
hooked to such an antenna and feed-line should be given a good earth ground.

If the above is coupled with a good understanding, awareness, and
practice of avoiding "ground loops", I think one can claim to have a
good and adequate grounding system. Ground loops are well discussed in
books, mags, and internet pages, etc.

In planes and outer space the earth ground can be ignored, your crafts
metallic shell will serve.

Regards,
JS

What is RF ground?
 

On Sat, 11 Nov 2006 12:06:16 -0000, "David" nospam@nospam wrote:

What would you define RF ground as? There seem to be a lot of different
ideas.

Hi David,

This is another instance of scale matters. Ground is meant to imply
an infinite resource of charge with no impedance to its flow.

Of course, "infinite" and "no impedance" are factors that are the
first casualties when RF is added as a requirment. This is from the
simple consequence of scale, because distance causes phase shifts and
brings impedance. A long wire that is perfectly capable as a ground
lead for 60 Hz can become a liability to short wavelength RF. That
wire (that we call ground) may connect to an infinite resource of
charge (the proper ground), but that charge can't get to the other end
because of possibly infinite impedances [again, infinite is in the eye
of the creator].

If you can contrive to make that lead to ground half a wavelength long
to the RF of your interest, that wire ceases to offer impedance and
acts much as you would demand of a ground wire. Curiosly enough, it
will never be zero impedance because it qualifies as a radiator (the
paradox of ground) which adds the loss of radiation. For most
purposes, however, it may be your only choice and you live with it.

Now, when we get to the actual mud of ground, and how well it performs
as an infinite resource of charge, RF still brings problems of scale
because that mud will also exhibit impedances correlated to wavelength
(corrected for velocity factors) that disconnect it from the total
earth's resource for infinite charge. This is why you lay down
radials (which simply increases coverage, but never completely escapes
the scale of wavelenght problem).

Moral to this tale:
Put your source (transmitter) as close to the mud as possible;
lay out as much copper as you can from that point to suit
a broader range of frequencies.

Alternative moral:
Put your source (transmitter) as far from the mud as possible;
Use a dipole and insure there are no connections to ground
whatever. Any violation of this last rule brings grief.
Such violations are legion and few escape.

73's
Richard Clark, KB7QHC

What is RF ground?
 

"John Smith" wrote in message
...
David wrote:
What would you define RF ground as? There seem to be a lot of different
ideas.

David:

Ground can be a relative thing. What I have always found to be good
advice is that EVERY ground, at some point, be allowed to reach a low
ohmic earth ground (best possible if it all occurs at the exact same earth
ground point--or no current flows and there is no voltage potential
between such grounds.) For example, although a dipole needs no rf ground
directly at the point it connects to the feed-line, the rig hooked to such
an antenna and feed-line should be given a good earth ground.
snip


Regards,
JS

When you refer to hooking the rig/dipole to a good earth ground, are you
still talking about an rf ground, or a safety ground?
I see no requirement to connect a nicely matched dipole to an earth ground
for rf purposes. For example, a battery operated transmitter feeding a
dummy load wouldn't need one either.

What is RF ground?
 

Wayne wrote:
"John Smith" wrote in message
...
David wrote:
What would you define RF ground as? There seem to be a lot of different
ideas.
David:

Ground can be a relative thing. What I have always found to be good
advice is that EVERY ground, at some point, be allowed to reach a low
ohmic earth ground (best possible if it all occurs at the exact same earth
ground point--or no current flows and there is no voltage potential
between such grounds.) For example, although a dipole needs no rf ground
directly at the point it connects to the feed-line, the rig hooked to such
an antenna and feed-line should be given a good earth ground.
snip

Regards,
JS

When you refer to hooking the rig/dipole to a good earth ground, are you
still talking about an rf ground, or a safety ground?
I see no requirement to connect a nicely matched dipole to an earth ground
for rf purposes. For example, a battery operated transmitter feeding a
dummy load wouldn't need one either.



Wayne:

Both. Only a dummy would think he needed an rf ground for a watt burner
of proper impedance.

However, there always is that "special case;" if the nitwit was running
a kw off a forklift battery, he just might want that rf ground.

JS

What is RF ground?
 

An RF ground is where RF energy flows into the earth. A lot of folks
misuse the word "ground" when they really mean a common connection
point, which may or may not have anything to do with earth. Be careful
to define just what you mean.

Bill, W6WRT


------------ ORIGINAL MESSAGE ------------

On Sat, 11 Nov 2006 12:06:16 -0000, "David" nospam@nospam wrote:

What would you define RF ground as? There seem to be a lot of different
ideas.

What is RF ground?
 

but rf doesn't flow 'into the earth'. rf current is always trying to
complete the circuit back to it's source... i.e. 'ground radials' under a
vertical are collecting the current and returning it to the feedpoint, so
they are actually 'sucking' rf out of the ground. the 'ground' connection
to a radio feeding a dipole is actually returning current from the ground
back to the feedpoint via the outside of the coax shield... that is why you
can get high voltages at the radio end of the cable, if too much current is
coupled from the antenna onto other conductors connected to 'ground' they
will feed current back through the radio 'ground' and out the shield of the
feedline to get to the feedpoint, and if you happen to be too close to the
antenna or some other object that couples the rf to you then you get burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.


"Bill Turner" wrote in message
...
An RF ground is where RF energy flows into the earth. A lot of folks
misuse the word "ground" when they really mean a common connection
point, which may or may not have anything to do with earth. Be careful
to define just what you mean.

Bill, W6WRT


------------ ORIGINAL MESSAGE ------------

On Sat, 11 Nov 2006 12:06:16 -0000, "David" nospam@nospam wrote:

What would you define RF ground as? There seem to be a lot of different
ideas.

What is RF ground?
 

Dave wrote:
but rf doesn't flow 'into the earth'. rf current is always trying to
complete the circuit back to it's source... i.e. 'ground radials' under a
vertical are collecting the current and returning it to the feedpoint, so
they are actually 'sucking' rf out of the ground. the 'ground' connection
to a radio feeding a dipole is actually returning current from the ground
back to the feedpoint via the outside of the coax shield... that is why you
can get high voltages at the radio end of the cable, if too much current is
coupled from the antenna onto other conductors connected to 'ground' they
will feed current back through the radio 'ground' and out the shield of the
feedline to get to the feedpoint, and if you happen to be too close to the
antenna or some other object that couples the rf to you then you get burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.


"Bill Turner" wrote in message
...
An RF ground is where RF energy flows into the earth. A lot of folks
misuse the word "ground" when they really mean a common connection
point, which may or may not have anything to do with earth. Be careful
to define just what you mean.

Bill, W6WRT


------------ ORIGINAL MESSAGE ------------

On Sat, 11 Nov 2006 12:06:16 -0000, "David" nospam@nospam wrote:

What would you define RF ground as? There seem to be a lot of different
ideas.




Correct. If pink fairies dance the head of the pin, all bets are off.
Although everything applies if dancing blue fairies...

JS

float? What is RF ground?
 

Alternative moral:
Put your source (transmitter) as far from the mud as possible;
Use a dipole and insure there are no connections to ground
whatever. Any violation of this last rule brings grief.
Such violations are legion and few escape.



Hi Rich

This knocked the gerbil off his wheel

so if i am doing the above, do you mean, no coaxl shield to ground or
did you really really mean not even a ground to my rig chassies?
i understand the dipole is ballanced at that point and the antenna
dosn't need a gnd (plane) radial (min is a center feed equal l)


so i would just have a rig and antenna nothing else??

(presume my electrical gnd is ok on the aka 3prong plug)

What is RF ground?
 

On Sun, 12 Nov 2006 15:14:49 -0000, "Dave" wrote:

but rf doesn't flow 'into the earth'.

Hi Dave,

That statement is contradiction to the following:

'ground radials' ... are ... 'sucking' rf out of the ground.

It necessarily follows that RF does flow "into" the earth by your own
admission of it coming out (by whatever means).

the 'ground' connection
to a radio feeding a dipole is actually returning current from the ground
back to the feedpoint via the outside of the coax shield...

Very true. However, the ellipsis (...) elongates a 25 word statement
into an 118 word run-on sentence:

that is why you
can get high voltages at the radio end of the cable, if too much current is
coupled from the antenna onto other conductors connected to 'ground' they
will feed current back through the radio 'ground' and out the shield of the
feedline to get to the feedpoint, and if you happen to be too close to the
antenna or some other object that couples the rf to you then you get burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.

If I try to parse the intent of this, it becomes a string of
assertions held in suspension until the summary that ties them
together. That never happens. The conclusion:
then you get burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.
bears no relation to the matter of currents in the earth - except as a
consequence to rather perverse conditions.

73's
Richard Clark, KB7QHC

What is RF ground?
 

"Richard Clark" wrote in message
...
On Sun, 12 Nov 2006 15:14:49 -0000, "Dave" wrote:

but rf doesn't flow 'into the earth'.

Hi Dave,

That statement is contradiction to the following:

'ground radials' ... are ... 'sucking' rf out of the ground.

It necessarily follows that RF does flow "into" the earth by your own
admission of it coming out (by whatever means).

in context of the message i was replying to the writer implied that rf
flowed 'into' the earth and that was the end of it, more correctly it could
be said that rf flows 'through' the earth, but it doesn't dissappear 'into'
the earth.


the 'ground' connection
to a radio feeding a dipole is actually returning current from the ground
back to the feedpoint via the outside of the coax shield...

Very true. However, the ellipsis (...) elongates a 25 word statement
into an 118 word run-on sentence:

i have been told before that i have very long trains of thought, usually i
am just trying to be descriptive enough for someone else to follow along...
and i just like ellipsis.


that is why you
can get high voltages at the radio end of the cable, if too much current
is
coupled from the antenna onto other conductors connected to 'ground' they
will feed current back through the radio 'ground' and out the shield of
the
feedline to get to the feedpoint, and if you happen to be too close to the
antenna or some other object that couples the rf to you then you get
burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.

If I try to parse the intent of this, it becomes a string of
assertions held in suspension until the summary that ties them
together. That never happens. The conclusion:
then you get burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.
bears no relation to the matter of currents in the earth - except as a
consequence to rather perverse conditions.

it relates to the common assumption that the radio case, coax shield, and
other items connected to a common 'ground' are at 'rf ground'. ignoring the
'earth', there is also the common misconception that things tied together to
the often discussed 'single point ground' are all 'grounded'... something
that is not necesssarily true when dealing with rf.

What is RF ground?
 

"John Smith" wrote
the 'ground' connection to a radio feeding a dipole is actually
returning current from the ground back to the feedpoint via the
outside of the coax shield.
______________

Usually there are good reasons to connect an earth-based tx chassis to an
earth r-f ground. But if the tx is feeding a dipole or other balanced
radiator, that radiator doesn't need or use a connection to an earth r-f
ground to generate its radiation. The current source for one side of the
dipole is the other side of the dipole.

For example consider airborne VHF tx/rx/antenna systems -- which work just
fine with no reference to an earth "r-f ground," whatsoever.

RF

float? What is RF ground?
 

Hi Myles,

Let's just cut to the chase with some selective editing:

On Sun, 12 Nov 2006 16:14:21 GMT, ml wrote:

Any violation of this last rule brings grief.
Such violations are legion and few escape.

(presume my electrical gnd is ok on the aka 3prong plug)

B I N G O !

You have won the traditional violation of the rule. This is the
meaning of "legion," there are many, many, many such examples. Those
who violate this rule are often blindsided by other violations along
the way.

What is the third prong of the 3 prong plug for? Most would say
ground (and be blindsided to the complete term being "safety" ground).
The 3rd prong is not designed to be current carrying in the
conventional sense, only in the safety sense when the neutral wire or
hot wire becomes exposed to the device user (basically forcing a short
circuit that then opens through a blown fuse).

So, you have TWO paths to ground:
1. Through neutral;
2. through safety ground.

The question becomes:
"What is the quality of it being RF ground?"
Answer:
"Neither 1 nor 2 above were ever considered
in those terms. Hence the quality of their being
RF ground is unknown and the presumption of being
poor examples is a reasonable expectation."

The next question becomes:
"Why do I need their ground proximity?"
Answer:
"You don't - unless...."

Unless
1. You are powering off the Mains;
2. Powering off battery that is being recharged off the Mains.

Both numbers 1 & 2 are a frequent blindside to those attempting to
isolate ground loops.

73's
Richard Clark, KB7QHC

What is RF ground?
 

On Sun, 12 Nov 2006 19:25:38 -0000, "Dave" wrote:

in context of the message i was replying to the writer implied that rf
flowed 'into' the earth and that was the end of it, more correctly it could
be said that rf flows 'through' the earth, but it doesn't dissappear 'into'
the earth.

Hi Dave,

True, but knowing Bill, I doubt his description was meant to be so
literal as to having current disappear into the earth.

In the sense of RF ground, already described by me earlier, ground is
a pool of infinite charge and as such current into it does disappear.
Otherwise, it would perturb and become less than a ground, its
potential would elevate and that elevation would be in reference to
some other ground.

This is a true picture of the reality of ground as such perturbation
does just this, and is evidenced by local variations of potential to
other "grounds." However, this reduces the discussion to one of
infinite regression and over-qualifies an answer to the primary
question.

i have been told before that i have very long trains of thought, usually i
am just trying to be descriptive enough for someone else to follow along...
and i just like ellipsis.

Up to the ellipsis was fine. The better part of writing is what you
leave behind after you trim off the fat.

it relates to the common assumption that the radio case, coax shield, and
other items connected to a common 'ground' are at 'rf ground'. ignoring the
'earth', there is also the common misconception that things tied together to
the often discussed 'single point ground' are all 'grounded'... something
that is not necesssarily true when dealing with rf.

I can follow the argument for concern, but you really don't offer any
context. There are far more examples of grounding working than not;
and your brush has tarred them all equally.

There is the practical answer to the question of RF ground, and there
is the literal answer (or academic, if you prefer). The practical
answer might have the user elevated hundreds of volts above academic
RF ground. That user might never perceive it in any way because the
user may have contrived to build a virtual ground that satisfies all
the requirements for operating without suffering themselves or any one
else.

73's
Richard Clark, KB7QHC

What is RF ground?
 

In article ,
Richard Clark wrote:

On Sun, 12 Nov 2006 15:14:49 -0000, "Dave" wrote:

but rf doesn't flow 'into the earth'.

Hi Dave,

That statement is contradiction to the following:

'ground radials' ... are ... 'sucking' rf out of the ground.

It necessarily follows that RF does flow "into" the earth by your own
admission of it coming out (by whatever means).

the 'ground' connection
to a radio feeding a dipole is actually returning current from the ground
back to the feedpoint via the outside of the coax shield...

Very true. However, the ellipsis (...) elongates a 25 word statement
into an 118 word run-on sentence:

that is why you
can get high voltages at the radio end of the cable, if too much current is
coupled from the antenna onto other conductors connected to 'ground' they
will feed current back through the radio 'ground' and out the shield of the
feedline to get to the feedpoint, and if you happen to be too close to the
antenna or some other object that couples the rf to you then you get burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.

If I try to parse the intent of this, it becomes a string of
assertions held in suspension until the summary that ties them
together. That never happens. The conclusion:
then you get burned
when the rf from you flows back to the radio when you touch something that
is 'grounded'.
bears no relation to the matter of currents in the earth - except as a
consequence to rather perverse conditions.

73's
Richard Clark, KB7QHC

In other words...... the guy is so full of ****, his eyes are brown.....

What is RF ground?
 

Richard Fry wrote:
"John Smith" wrote
the 'ground' connection to a radio feeding a dipole is actually
returning current from the ground back to the feedpoint via the
outside of the coax shield.
______________

Usually there are good reasons to connect an earth-based tx chassis to
an earth r-f ground. But if the tx is feeding a dipole or other
balanced radiator, that radiator doesn't need or use a connection to an
earth r-f ground to generate its radiation. The current source for one
side of the dipole is the other side of the dipole.

For example consider airborne VHF tx/rx/antenna systems -- which work
just fine with no reference to an earth "r-f ground," whatsoever.

RF

Richard:

I have been "short" with some because I suspect they "pull my leg" a
bit. I have no problem with the example you cite. However, if someone
is at the point where they really need to ask, better for them to be
overly cautious and "overly grounded." It would bother me is someone
was injured or worse from some oversight of mine, something I was not
clear enough on. And yes, I realize that even attempting to avoid such
errors, I may make them.

So, we agree...

JS

What is RF ground?
 

"John Smith" wrote in message
...
Wayne wrote:
"John Smith" wrote in message
...
David wrote:
What would you define RF ground as? There seem to be a lot of different
ideas.
David:

Ground can be a relative thing. What I have always found to be good
advice is that EVERY ground, at some point, be allowed to reach a low
ohmic earth ground (best possible if it all occurs at the exact same
earth ground point--or no current flows and there is no voltage
potential between such grounds.) For example, although a dipole needs
no rf ground directly at the point it connects to the feed-line, the rig
hooked to such an antenna and feed-line should be given a good earth
ground.
snip

Regards,
JS

When you refer to hooking the rig/dipole to a good earth ground, are you
still talking about an rf ground, or a safety ground?
I see no requirement to connect a nicely matched dipole to an earth
ground for rf purposes. For example, a battery operated transmitter
feeding a dummy load wouldn't need one either.

Wayne:

Both. Only a dummy would think he needed an rf ground for a watt burner
of proper impedance.

However, there always is that "special case;" if the nitwit was running a
kw off a forklift battery, he just might want that rf ground.

JS

Well, my question is in the context of rf ground being a function of the
antenna subsystem. It wasn't clear why you recommend use of a transmitter
rf ground, if the antenna system doesn't require it. Yes, I would run some
sort of rf ground at the rig if I were using a random wire fed with a tuner
in the shack, because the antenna system requires it.

My own setup is a ground mounted vertical with a modest 10 foot diameter
ground system. The "rf ground" is at the base of the antenna (as is a
separate lightning ground). The shack is on the second floor, and has only
a safety ground at the rig.

What is RF ground?
 

Wayne wrote:
"John Smith" wrote in message
...
Wayne wrote:
"John Smith" wrote in message
JS

Well, my question is in the context of rf ground being a function of the
antenna subsystem. It wasn't clear why you recommend use of a transmitter
rf ground, if the antenna system doesn't require it. Yes, I would run some
sort of rf ground at the rig if I were using a random wire fed with a tuner
in the shack, because the antenna system requires it.

My own setup is a ground mounted vertical with a modest 10 foot diameter
ground system. The "rf ground" is at the base of the antenna (as is a
separate lightning ground). The shack is on the second floor, and has only
a safety ground at the rig.


Wayne:

I see...

An antenna design requiring a system of underground ground radial(s) to
function correctly (or at least as designed), (or, for that matter,
above ground radial(s) running though bushes) would only be a "complete
antenna" if such were taken for granted had already been installed
(meaning the "rf ground-establishing" radials.)

And, if there were any chance at all I would be running a kw, and
touching both the ground radials and the ground at the same time AND
wanted to cover all special case/weird/worst-possible-cases (and I do
propose everyone should plan on this)... I would provide a nice low
ohmic earth ground for such radials (possibly useful for safety only.)
But then I am a sissy and find rf burns painful.

I didn't realize you were asking me, "If the guy has only installed half
of the antenna, should he install the "other half?" The answer to that
is all too obvious.

Yanno, those trick questions always throw me!

Regards,
JS

What is RF ground?
 

David wrote:
What would you define RF ground as? There seem to be a lot of different
ideas

An ideal RF ground is a point or node where RF current can be imposed
and the result is no change in RF potential (voltage). That is to say
the impedance is zero. All real world implimentations of "RF ground"
are less than perfect as measured by their real world impedance.

What is RF ground?
 

ORIGINAL MESSAGE:

On Sun, 12 Nov 2006 15:14:49 -0000, "Dave" wrote:


but rf doesn't flow 'into the earth'

------------ REPLY FOLLOWS ------------

Beware of making broad statements that are supposed to be true in all
cases. The one above is not.

Bill, W6WRT

What is RF ground?
 

In article ,
Bill Turner wrote:

ORIGINAL MESSAGE:

On Sun, 12 Nov 2006 15:14:49 -0000, "Dave" wrote:


but rf doesn't flow 'into the earth'

------------ REPLY FOLLOWS ------------

Beware of making broad statements that are supposed to be true in all
cases. The one above is not.

Bill, W6WRT

One statement that IS True, and has been around "Forever":

Ground is not Ground, the World Around........


Me and RF Ground, is not Ground Ground........

float? What is RF ground?
 

the real fooling part is somthing kinda simple, can be sooo tricky

In article ,
Richard Clark wrote:

Hi Myles,

Let's just cut to the chase with some selective editing:

On Sun, 12 Nov 2006 16:14:21 GMT, ml wrote:

Any violation of this last rule brings grief.
Such violations are legion and few escape.

(presume my electrical gnd is ok on the aka 3prong plug)

B I N G O !

You have won the traditional violation of the rule. This is the
meaning of "legion," there are many, many, many such examples. Those
who violate this rule are often blindsided by other violations along
the way.

What is the third prong of the 3 prong plug for? Most would say
ground (and be blindsided to the complete term being "safety" ground).
The 3rd prong is not designed to be current carrying in the
conventional sense, only in the safety sense when the neutral wire or
hot wire becomes exposed to the device user (basically forcing a short
circuit that then opens through a blown fuse).

So, you have TWO paths to ground:
1. Through neutral;
2. through safety ground.

The question becomes:
"What is the quality of it being RF ground?"
Answer:
"Neither 1 nor 2 above were ever considered
in those terms. Hence the quality of their being
RF ground is unknown and the presumption of being
poor examples is a reasonable expectation."

The next question becomes:
"Why do I need their ground proximity?"
Answer:
"You don't - unless...."

Unless
1. You are powering off the Mains;
2. Powering off battery that is being recharged off the Mains.

Both numbers 1 & 2 are a frequent blindside to those attempting to
isolate ground loops.

73's
Richard Clark, KB7QHC

What is RF ground?
 

Me wrote:
In article ,
Bill Turner wrote:

ORIGINAL MESSAGE:

On Sun, 12 Nov 2006 15:14:49 -0000, "Dave" wrote:


but rf doesn't flow 'into the earth'
------------ REPLY FOLLOWS ------------

Beware of making broad statements that are supposed to be true in all
cases. The one above is not.

Bill, W6WRT

One statement that IS True, and has been around "Forever":

Ground is not Ground, the World Around........


Me and RF Ground, is not Ground Ground........

As was pointed out before and mentioned by someone else, if the antenna
is mounted so as to be fed by a feed-line running at ground level AND
fed at this low point (coax probably best in such close proximity to
"ground ground")--and a set of rf grounding radials emanate in all
directions from this feed point (but just below ground), BOTH EARTH
GROUND and RF GROUND are at or "are very near" exact points.

For most other situations which come to mind, your statement is true.

JS

What is RF ground?
 

Bill Turner wrote:
ORIGINAL MESSAGE:

On Sun, 12 Nov 2006 15:14:49 -0000, "Dave" wrote:


but rf doesn't flow 'into the earth'

------------ REPLY FOLLOWS ------------

Beware of making broad statements that are supposed to be true in all
cases. The one above is not.

Bill, W6WRT

Bill,

The broadest and most general statement I made in my post was "All real
world implimentations of "RF ground" are less than perfect". I take it
from your negitive post that you disagree with this point.