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Old Feb 24, 2011, 07:11 PM
IBCrazy is offline
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Quote:
Originally Posted by Devonboy View Post
I always use coax in multiples of a half wavelength at the frequency in use, also allow for the velocity factor of the coax.
This way, there is less chance of the coax becoming a matching transformer and the potential for current flow on the cable itself.

Nigel.
Would you mind if I take exception to this? If the antenna is built properly and resonates at the proper 50 ohm impedance, then a 50 Ohm matching stub will result in the exact same impedance.

Remember your equation:

Zin = Z0^2/ZL

If Z0 = ZL = 50 Ohms then Zin = 50 Ohms.

Thus you can make the cable any length you want without harming the impedance match.

-Alex
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