Need a 5KW 4:1 Balun
guy...@ibm.net
5 KW 1:1 and 4:1 baluns listed, both current fed
and voltage feed baluns.
Here's the questions --
What's the difference between a current fed and voltage fed balun?
Can a voltage fed balun be used where you would normally use a current
fed balun?
Does anyone know the web site URL of a balun Manufacturer that sells 5
KW 4:1 baluns?.
Thanks to everyone who responds.
W4GBU
R. Makul K1XV
>Does anyone know the web site URL of a balun Manufacturer that sells 5
>KW 4:1 baluns?.
==============
Try Centaur Electronics, http://www.baluns.com
I believe they have a "Big Bertha" series good for up to 10 KW. I
have one of their "little" 3 KW models.
Ray K1XV
Robert Lay
>I saw a web site once with a list of High Quality
>5 KW 1:1 and 4:1 baluns listed, both current fed
>and voltage feed baluns.
>
>Here's the questions --
>What's the difference between a current fed and voltage fed balun?
>Can a voltage fed balun be used where you would normally use a current
>fed balun?
I certainly do not claim to be an expert on baluns, but I have been
using them since 1963 or 64. In my work on 70 MHz amplifier design I
tried dutifully to understand the work of Ruthroff and implement his
principals in my designs.
Here is some food for thought.
If a transformer type balun (as opposed to a multiturn coax loop),
the balun will see a load impedance and that load impledance may or
may not be the impedance for which the balun is designed. Furthermore,
if the balun has a ferrite core, the voltage and frequency at which
the balun is excited may or may not be in a linear region of
operation. However, if all is kosher, the balun will be operating
into its proper impedance, and the frequency and power level will be
within specifications. Under those conditions, and no other, the balun
could be EITHER a voltage type or a current type, and I don't think
that you or the balun would see any difference.
However, under conditions of mismatch and under out of band conditions
(meaning out of the range of frequencies for which the balun is
designed - not out of the ham band, Hi!), all bets are off. Under
those conditions the balun may not be able to do what it was intended
to do - whatever that might be (usually, its objective is to block
common mode currents). If one understands the theory of the balun and
fully understands to what purpose it is being employed, then I presume
that circumstances would dictate one type of balun in preference to
another. From my limited understanding of the difference, is primarily
one of how well the balun blocks common mode currents, and the current
balun is supposed to do the better job.
Reg Edwards
your own. Calculate efficiency.
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guy...@ibm.net wrote in article <365AA0EE...@ibm.net>...
> I saw a web site once with a list of High Quality
> 5 KW 1:1 and 4:1 baluns listed, both current fed
> and voltage feed baluns.
>
> Here's the questions --
> What's the difference between a current fed and voltage fed balun?
> Can a voltage fed balun be used where you would normally use a
current
> fed balun?
> Does anyone know the web site URL of a balun Manufacturer that
sells 5
> KW 4:1 baluns?.
>
Roy Lewallen
>
> I saw a web site once with a list of High Quality
> 5 KW 1:1 and 4:1 baluns listed, both current fed
> and voltage feed baluns.
>
> Here's the questions --
> What's the difference between a current fed and voltage fed balun?
> Can a voltage fed balun be used where you would normally use a current
> fed balun?
> Does anyone know the web site URL of a balun Manufacturer that sells 5
> KW 4:1 baluns?.
>
> Thanks to everyone who responds.
> W4GBU
A "voltage" balun insures that the voltages at the two output
conductors are equal and opposite relative to the "cold" side of the
input. This type of balun is appropriate for driving differential
amplifiers, for example. A "current" balun insures that the currents
on the two conductors are equal and opposite. When used on an antenna
feedline, this eliminates common-mode current, which causes radiation.
In the case of coax, common-mode current flows on the outside of the
coax, so a properly operating balun reduces this current to a small
value. (Of course, no balun is perfect, so the desired effect of
voltage or current balance isn't perfect either.) If a perfect voltage
balun is used to feed an antenna that's perfectly balanced with
respect to ground (and the coupling from the antenna to the feedline
is also perfectly balanced), there won't be any common mode current.
But if the antenna or feedline isn't completely balanced, the voltage
balun will cause a common-mode current as a necessary condition to
effect voltage balance. A "current" balun, on the other hand, always
tends to reduce common-mode current, regardless of the symmetry of the
antenna. For that reason, it's preferred for use with antennas.
There's more about this in "Baluns: What They Do and How They Do It"
in the _ARRL Antenna Compendium_, Vol. 2.
A 4:1 voltage balun can be made with a single core. A 4:1 current
balun requires two cores or, I believe, a single two-hole core if done
correctly.
Sorry, I don't know the source of 5 KW baluns.
Roy Lewallen, W7EL
W6RCecilA
> Sorry, I don't know the source of 5 KW baluns.
The company that Sevick is associated with sells an alleged
10kW 4:1 balun. I have one. It's number is HBHC-200 if I
remember right. Sorry, the name of the company has slipped
my mind. Seems my mind has retired too.
--
73, Cecil, W6RCA http://people.delphi.com/CecilMoore
Ralph Holland
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Brian Kelly
> Roy Lewallen wrote:
> > Sorry, I don't know the source of 5 KW baluns.
>
> The company that Sevick is associated with sells an alleged
> 10kW 4:1 balun. I have one. It's number is HBHC-200 if I
> remember right. Sorry, the name of the company has slipped
> my mind. Seems my mind has retired too.
We "noticed".
> --
> 73, Cecil, W6RCA http://people.delphi.com/CecilMoore
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Charles Jack Hawley
W6RCecilA wrote:
> Roy Lewallen wrote:
> > Sorry, I don't know the source of 5 KW baluns.
>
> The company that Sevick is associated with sells an alleged
> 10kW 4:1 balun. I have one. It's number is HBHC-200 if I
> remember right. Sorry, the name of the company has slipped
> my mind. Seems my mind has retired too.
Amidon, 714-850-4660
> --
> 73, Cecil, W6RCA http://people.delphi.com/CecilMoore
Chuck
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Ralph Holland
Sorry folks,
My signature file was using MSDOS file separators in the URL - the correction
appears below.
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I used the MSDOS file separator \ instead of the Unix separator / in my
previous URL.
It has been corrected below.
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Regards, (73)
Ralph Holland (VK1BRH)
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