The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still balanced?

On 8/4/2015 11:39 AM, John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still balanced?

Is *what* still balanced? The antenna hasn't changed and is still
balanced. The generator hasn't changed and is still balanced. But you
have added a wire which will load the generator and serve as an element
of the antenna changing the radiation pattern. How significantly the
pattern will change depends on the orientation of the wire and what it
connects to, if anything. There is also the issue of how much energy is
transmitted along the wire to whatever is connected to it.

--

Rick

On 8/4/2015 11:31 AM, rickman wrote:
On 8/4/2015 11:39 AM, John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still
balanced?

Is *what* still balanced? The antenna hasn't changed and is still
balanced.

Well, the starting point is this:

----------0-----------

Where the 0 is the generator.

Then we attach a wire like so:

----------0.----------
|
|
|
|
|

I don't understand how the antenna has not changed.

The generator hasn't changed and is still balanced.

I do not understand how a two-terminal generator can be described as
either balanced or unbalanced.

But you
have added a wire which will load the generator and serve as an element
of the antenna changing the radiation pattern. How significantly the
pattern will change depends on the orientation of the wire and what it
connects to, if anything. There is also the issue of how much energy is
transmitted along the wire to whatever is connected to it.


Please disregard the radiation pattern in this thread.

On 8/5/2015 9:47 AM, John S wrote:
On 8/4/2015 11:31 AM, rickman wrote:
On 8/4/2015 11:39 AM, John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still
balanced?

Is *what* still balanced? The antenna hasn't changed and is still
balanced.

Well, the starting point is this:

----------0-----------

Where the 0 is the generator.

Then we attach a wire like so:

----------0.----------
|
|
|
|
|

I don't understand how the antenna has not changed.

The generator hasn't changed and is still balanced.

I do not understand how a two-terminal generator can be described as
either balanced or unbalanced.

But you
have added a wire which will load the generator and serve as an element
of the antenna changing the radiation pattern. How significantly the
pattern will change depends on the orientation of the wire and what it
connects to, if anything. There is also the issue of how much energy is
transmitted along the wire to whatever is connected to it.


Please disregard the radiation pattern in this thread.

If you consider the wire to be part of the antenna, then the antenna has
changed.

So what is your question?

--

Rick

On 8/5/2015 10:28 AM, rickman wrote:
On 8/5/2015 9:47 AM, John S wrote:
On 8/4/2015 11:31 AM, rickman wrote:
On 8/4/2015 11:39 AM, John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with
an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still
balanced?

Is *what* still balanced? The antenna hasn't changed and is still
balanced.

Well, the starting point is this:

----------0-----------

Where the 0 is the generator.

Then we attach a wire like so:

----------0.----------
|
|
|
|
|

I don't understand how the antenna has not changed.

The generator hasn't changed and is still balanced.

I do not understand how a two-terminal generator can be described as
either balanced or unbalanced.

But you
have added a wire which will load the generator and serve as an element
of the antenna changing the radiation pattern. How significantly the
pattern will change depends on the orientation of the wire and what it
connects to, if anything. There is also the issue of how much energy is
transmitted along the wire to whatever is connected to it.


Please disregard the radiation pattern in this thread.

If you consider the wire to be part of the antenna, then the antenna has
changed.


In what way could the wire not be part of the antenna?


So what is your question?


You will find that in my OP. The question mark identifies it.

On 8/6/2015 9:48 AM, John S wrote:
On 8/5/2015 10:28 AM, rickman wrote:
On 8/5/2015 9:47 AM, John S wrote:
On 8/4/2015 11:31 AM, rickman wrote:
On 8/4/2015 11:39 AM, John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax
attachment.

Starting from the simplest of all situations, assume a dipole with
an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still
balanced?

Is *what* still balanced? The antenna hasn't changed and is still
balanced.

Well, the starting point is this:

----------0-----------

Where the 0 is the generator.

Then we attach a wire like so:

----------0.----------
|
|
|
|
|

I don't understand how the antenna has not changed.

The generator hasn't changed and is still balanced.

I do not understand how a two-terminal generator can be described as
either balanced or unbalanced.

But you
have added a wire which will load the generator and serve as an element
of the antenna changing the radiation pattern. How significantly the
pattern will change depends on the orientation of the wire and what it
connects to, if anything. There is also the issue of how much
energy is
transmitted along the wire to whatever is connected to it.


Please disregard the radiation pattern in this thread.

If you consider the wire to be part of the antenna, then the antenna has
changed.


In what way could the wire not be part of the antenna?

By your construction. You said you have an antenna and a wire. If you
meant for the wire to be part of the antenna you would have said that in
your OP.


So what is your question?


You will find that in my OP. The question mark identifies it.

"Is it still balanced?" I asked before, what is "it"?

You also said, "I do not understand how a two-terminal generator can be
described as either balanced or unbalanced."

A two terminal generator may have series resistance, for example. That
series resistance may not be evenly distributed. More resistance on one
leg than the other and it is no longer balanced. If the series
resistance is zero, then it would need a *lot* more of it on one leg
than the other.

--

Rick

On 8/5/2015 8:47 AM, John S wrote:
On 8/4/2015 11:31 AM, rickman wrote:
On 8/4/2015 11:39 AM, John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with an RF
generator in the middle.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still
balanced?

Well, the starting point is this:

----------0-----------

Where the 0 is the generator.

So, if any current flows, it will be the same magnitude in each wire
like this:

I - I -
-----------0----------

Then we attach a wire like so:

----------0.----------
|
|
|
|
|


Now, if we have a current in the left-hand side, it MUST be balanced by
the SUM of the currents in the right hand side. Like this:

I(t)- I(1)-
----------0+---------
|
| I(2)
| |
| V
|

So, I(t) = I(1) + I(2)

The point here is that there will be a current (I(2)) in a coax shield
attached to the antenna whether there is a ground connection or not.
There will be a current (I(2)) in a coax shield attached to the antenna
whether the antenna is matched or not. I do not see any other alternatives.

On 8/9/2015 12:36 PM, John S wrote:
On 8/5/2015 8:47 AM, John S wrote:
On 8/4/2015 11:31 AM, rickman wrote:
On 8/4/2015 11:39 AM, John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with
an RF
generator in the middle.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still
balanced?

Well, the starting point is this:

----------0-----------

Where the 0 is the generator.

So, if any current flows, it will be the same magnitude in each wire
like this:

I - I -
-----------0----------

Then we attach a wire like so:

----------0.----------
|
|
|
|
|


Now, if we have a current in the left-hand side, it MUST be balanced by
the SUM of the currents in the right hand side. Like this:

I(t)- I(1)-
----------0+---------
|
| I(2)
| |
| V
|

So, I(t) = I(1) + I(2)

The point here is that there will be a current (I(2)) in a coax shield
attached to the antenna whether there is a ground connection or not.
There will be a current (I(2)) in a coax shield attached to the antenna
whether the antenna is matched or not. I do not see any other alternatives.

I don't see how anyone could argue against that... although some seem to
based on the idea that because the antenna is "balanced" all the current
will flow equally to both antenna elements and there will be none left
to flow on the shield.

In another group I explained how the the current would flow on both the
antenna element and the shield according to the impedance and one of the
very experienced members replied that I should have been an RF engineer.
lol Seems some folks get this very basic concept wrong.

I think this is an example of how we use many generalizations which only
apply properly under specific conditions which we forget.

--

Rick

John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still balanced?

You have to clearly define "it".

The original antenna is still balanced, but the new antenna system is not
because of the 3rd wire.

The magnitude of the imbalance depends on the length and orientation of
that third wire and can be anywhere from insignificant to major.


--
Jim Pennino

On 8/4/2015 12:18 PM, wrote:
John S wrote:
The balun thread has become long (138 posts). I propose that we not
discuss baluns, but concentrate on antenna balance and coax attachment.

Starting from the simplest of all situations, assume a dipole with an RF
generator in the middle. If we can't agree that this is a balanced
system, then we have nothing left to discuss.

Connect an additional wire to one side of the source so that you have
one wire on one side and two wires on the other side. Is it still balanced?

You have to clearly define "it".

I have problems with defining my thoughts. But, you seem to have looked
beyond my deficiency:

The original antenna is still balanced, but the new antenna system is not
because of the 3rd wire.

The magnitude of the imbalance depends on the length and orientation of
that third wire and can be anywhere from insignificant to major.

That's the way I see it, too.