[Antennas] coax 'sweet length'

Mon Oct 11 10:29:56 EDT 2004

At 06:16 AM 10/11/2004, you wrote:
>Dear Danny,
>>All you have to do is go around the Smith Chart 1/2 electrical wavelength
>(which is a full circle on the Smith Chart) to see that the impedance seen
>at 1/2 wavelength distance is exactly the same as the terminating impedance.

Bob,
I hope we are talking about the same thing. Here is an example I just ran 
using TLW (the ARRL's transmission line calculating program). Using 
½-wavelength 7/8" hard line [about as close to lossless as I can find in 
the program] and setting the load impedance at R50 +J10 the program reports 
at the input of the line the impedance is R50 -J10.02.
Yes the impedance is the same magnitude (50.99 Ohms) but the sign has 
changed from +11º to -11º.
Danny
K6MHE