wrote:
Yes and I have to partially take back what I said; a balun CAN double
as a CM "choke" and a CM choke can double as a balun. If
one wishes to balance an unbalanced line with a CM choke, then the
impedance of the CM choke must match the source and the load, which
makes the CM choke a balun and no longer a choke :-)

Actually, a balun without a large choking impedance
is not very useful for ham antenna system applications.
The method that a W2DU balun uses to balance currents
at a dipole feedpoint *IS* nothing more than a large
choking impedance which discourages common-mode current
from flowing through the higher-the-better impedance.
I usually refer to the W2DU balun as a choke-balun.
--
73, Cecil http://www.w5dxp.com

On Sep 2, 7:26*am, Cecil Moore wrote:
wrote:
Yes and I have to partially take back what I said; a balun CAN double
as a CM "choke" and a CM choke can double as a balun. If
one wishes to balance an unbalanced line with a CM choke, then the
impedance of the CM choke must match the source and the load, which
makes the CM choke a balun and no longer a choke :-)

Actually, a balun without a large choking impedance
is not very useful for ham antenna system applications.
The method that a W2DU balun uses to balance currents
at a dipole feedpoint *IS* nothing more than a large
choking impedance which discourages common-mode current
from flowing through the higher-the-better impedance.
I usually refer to the W2DU balun as a choke-balun.
--
73, Cecil *http://www.w5dxp.com

I disagree. There is no choking, there is merely a polarity and phase
shift between the "primary" and "secondary" of the 1:1 balun
"transformer".

The best way I can easily express this is to consider a 1:1 240V 60 Hz
isolation transformer (yes, the balun acts theoretically in the same
manner). At the unbalanced input you connect 240V on one terminal and
earthed neutral on the other terminal. Now consider the isolated
secondary each feeding an equal resistive load to the center tap of
the secondary (analagous to radiation resistance). Across each load
we see 120V, 180 degrees out of phase. This is a balanced
transmission. Correct, this is not RF but it illustrates what the
balun is supposed to be doing. There is NO choking function at all if
it is working properly. There cannot be a choke when impedances are
matched, only when they are significantly mismatched.

wrote:

...
I disagree. There is no choking, there is merely a polarity and phase
shift between the "primary" and "secondary" of the 1:1 balun
"transformer".

The best way I can easily express this is to consider a 1:1 240V 60 Hz
isolation transformer (yes, the balun acts theoretically in the same
manner). ...

No. But you have focused on your error in thinking/logic/function. An
RF Transformers does what you state, lengths of transmission line
carrying RF behave in a different "mode." (uh, I hate that word ...)

Now, if you do some research, you can correct your error(s) ...

Regards,
JS

--
It is like a nightmare where the public servants are the people which
the police are supposed to protect us from!

On Sep 2, 10:43*pm, John Smith wrote:
wrote:
...
I disagree. There is no choking, there is merely a polarity and phase
shift between the "primary" and "secondary" of the 1:1 balun
"transformer".

The best way I can easily express this is to consider a 1:1 240V 60 Hz
isolation transformer (yes, the balun acts theoretically in the same
manner). ...

No. *But you have focused on your error in thinking/logic/function. *An
RF Transformers does what you state, lengths of transmission line
carrying RF behave in a different "mode." (uh, I hate that word ...)

Now, if you do some research, you can correct your error(s) ...

Regards,
JS

--
It is like a nightmare where the public servants are the people which
the police are supposed to protect us from!

A 1:1 balun IS an RF transformer. Lengths of transmission line wound
an air core can function as a 1:1 RF transformer. Does this in any way
show you the error you are making? Transformers operate in the same
way whether at 60Hz or RF. So much for your "No" statement which seems
to demonstrate a certain confidence masked in senility.

wrote:


A 1:1 balun IS an RF transformer. Lengths of transmission line wound
an air core can function as a 1:1 RF transformer. Does this in any way
show you the error you are making? Transformers operate in the same
way whether at 60Hz or RF. So much for your "No" statement which seems
to demonstrate a certain confidence masked in senility.

Actually, NO!

A 1:1 balun is a TLT, as stated, properly, by Ownen ...

But, what you speak of is frequently an RF Transformer ... how you keep
repeating that mistake speaks to your in ability to do research and
educate yourself ...

--
It is like a nightmare where the public servants are the people which
the police are supposed to protect us from!

On Sep 3, 10:54*pm, John Smith wrote:
wrote:

A 1:1 balun IS an RF transformer. Lengths of transmission line wound
an air core can function as a 1:1 RF transformer. Does this in any way
show you the error you are making? Transformers operate in the same
way whether at 60Hz or RF. So much for your "No" statement which seems
to demonstrate a certain confidence masked in senility.

Actually, NO!

A 1:1 balun is a TLT, as stated, properly, by Ownen ...

But, what you speak of is frequently an RF Transformer ... how you keep
repeating that mistake speaks to your in ability to do research and
educate yourself ...

it's not the heat it's the senility

wrote:

...
it's not the heat it's the senility

Be careful, a heat rash like that in the pubic area might be the sign of
a larger problem ... perhaps the whores on 65th street are better left
to themselves ... something to consider anyway.

Regards,
JS

--
It is like a nightmare where the public servants are the people which
the police are supposed to protect us from!

wrote:
I disagree. There is no choking, there is merely a polarity and phase
shift between the "primary" and "secondary" of the 1:1 balun
"transformer".

In a w2du balun, zero flux in the beads is introduced
by the transmission line currents. All of the flux in
the beads is introduced by common-mode currents. Thus
the impedance of the beads *IS* a choking impedance
aimed only at the common-mode currents.

My choke-balun is ten turns of RG-400 on an FT-240-77
toroid. It's only purpose is to provide a choking
impedance to common-mode current. That choke-balun
doesn't know if it is being used as a UNUN or as a
BALUN.

Most baluns are designed such that near-zero flux
is introduced in the ferrite toroid by the differential
mode currents. Essentially, the only flux introduced
in the toroid is due to common-mode. The resulting
impedance *IS* a choking impedance.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Most baluns are designed such that near-zero flux
is introduced in the ferrite toroid by the differential
mode currents.

That should have been, "Most 1:1 current baluns ..."
--
73, Cecil http://www.w5dxp.com