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Old November 15th 06, 06:14 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 168
Default Need design info on coax traps for dipoles

On Tue, 14 Nov 2006 08:25:17 GMT, Owen Duffy wrote:

On Mon, 13 Nov 2006 16:10:04 -0700, Wes Stewart
wrote:


Reducing frequency in search of the impedance maximum, I find it at
6.870MHz with inductance now 0.7+j144.3 around 20k ohms. This
impedance would appear in series with that of the inductor, so the
trap would have a Z somewhere around 20k ohms. (The Z is very
sensitive to the assumed resistance of the coil, and the loss in the
transmission line.)

Is there a flaw in this approach?


I think there is, the voltage drop across the coil will be very
similar to that looking into the coax, the the total voltage drop
across the whole trap might be more like double, and the impedance
more like double. I need to develop a more detailed model to get
better accuracy!

Owen
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