On Mon, 08 Aug 2005 02:47:27 GMT, S.Fritts wrote:




Because you cant run 50 ohm output to a 450 ohm impedeance...........


The chances of your balun seeing a 450-ohm impedance in the
configuration you are planing to use is right up there with wining the
state lottery.

What is important is the balun's choking impedance (that's the one
that blocks the common mode current) not its differential impedance.

I suggest you get a copy of TL Details
http://www.qsl.net/ac6la/tldetails.html
and check out just how much variation in impedance you balun will be
seeing.

73,
Danny, K6MHE

email: k6mheatarrldotnet
http://users.adelphia.net/~k6mhe/

On Mon, 08 Aug 2005 06:21:37 -0700, Dan Richardson wrote:



I suggest you get a copy of TL Details
http://www.qsl.net/ac6la/tldetails.html
and check out just how much variation in impedance you balun will be
seeing.

73,
Danny, K6MHE

email: k6mheatarrldotnet
http://users.adelphia.net/~k6mhe/

I'm trying that program out, and under Results, it gives an SWR and
and SWR (50). What's the difference in those two?

Bob
k5qwg

On Mon, 08 Aug 2005 17:09:06 GMT, Bob Miller
wrote:

I'm trying that program out, and under Results, it gives an SWR and
and SWR (50). What's the difference in those two?


The SWR (xx) is referenced to the prime center of the smith chart. If
you change that value the some other value the SWR (xx) value will
change to match it.

Hint: Allow your mouse to hover over any of the text boxes and you'll
see a brief description for the values.

73,
Danny, K6MHE

email: k6mheatarrldotnet
http://users.adelphia.net/~k6mhe/

On Mon, 08 Aug 2005 17:09:06 GMT, Bob Miller
wrote:

I'm trying that program out, and under Results, it gives an SWR and
and SWR (50). What's the difference in those two?

Bob, you will note that Dan develops an approximation for the actual
characteristic impedance of transmission line rather than use the
nominal characteristic impedance.

The SWR figure is calculated for the estimated characteristic
impedance, and the SWR(50) is calculated based on a characteristic
impedance of 50+j0.

Owen
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