"John Popelish" wrote in message
...
wrote:
John Popelish wrote:

SNIP
At low frequency, I understand how this is a good approach (though this
discussion was about the W2DU style choke balun). But at higher
frequencies, I am concerned that the turn to turn capacitance might
provide a low impedance path that parallels the choke. A string of beads
does not have this problem.


Hi John

"For what its worth", I have wounf the coax around a single ferrite toroid
with the exact amount of turns and spacing so the impedance along the
conductor of the coax outer shield was maximum, as in parallel resonance.
I cant claim that it does any better job than any other "1:1 balun", but it
worked for me.
My point is - The turn to turn "stray" capacitance doesnt necessarily have
to be a source of performance degradation.

Jerry

Jerry Martes wrote:
"John Popelish" wrote in message
...

wrote:

John Popelish wrote:


SNIP

At low frequency, I understand how this is a good approach (though this
discussion was about the W2DU style choke balun). But at higher
frequencies, I am concerned that the turn to turn capacitance might
provide a low impedance path that parallels the choke. A string of beads
does not have this problem.



Hi John

"For what its worth", I have wounf the coax around a single ferrite toroid
with the exact amount of turns and spacing so the impedance along the
conductor of the coax outer shield was maximum, as in parallel resonance.
I cant claim that it does any better job than any other "1:1 balun", but it
worked for me.
My point is - The turn to turn "stray" capacitance doesnt necessarily have
to be a source of performance degradation.

I think of it as more of a upper limit. Once you are above resonance,
the choke action has to drop. And if you are using one of the low
frequency ferrites, the resonance isn't going to be anything to write
home about either. ;-)

"John Popelish" wrote in message
...
Jerry Martes wrote:
"John Popelish" wrote in message
...

wrote:

John Popelish wrote:


SNIP

At low frequency, I understand how this is a good approach (though this
discussion was about the W2DU style choke balun). But at higher
frequencies, I am concerned that the turn to turn capacitance might
provide a low impedance path that parallels the choke. A string of beads
does not have this problem.



Hi John

"For what its worth", I have wounf the coax around a single ferrite
toroid with the exact amount of turns and spacing so the impedance along
the conductor of the coax outer shield was maximum, as in parallel
resonance. I cant claim that it does any better job than any other "1:1
balun", but it worked for me.
My point is - The turn to turn "stray" capacitance doesnt necessarily
have to be a source of performance degradation.

I think of it as more of a upper limit. Once you are above resonance, the
choke action has to drop. And if you are using one of the low frequency
ferrites, the resonance isn't going to be anything to write home about
either. ;-)


Hi John

I am not smart enough to be able to give instructions to *anyone*. But, I
have thought of "hi Q" resonance something I want to avoid anyway in making
a Balun. I was worried that a high Q resonant circuit without sisnificant
loss might assist coupling to the feed line if/when that feed line was close
to some multiple of a half wave.

Anyway, you get the idea I was trying to address concerning any worry
about stray capacitance ruining the Balun performance.

Jerry