May 6, 2014

FCC Technician Exam Question Of The Day (T7C06)

Q) What does an SWR reading of 4:1 mean?



A) An impedance mismatch




NJ2X Notes:
Amateur radios require an impedence match of 50-ohms in the coaxial cable, antenna, or any other device connected.  A mismatch between the radio and any of the devices in the chain will cause a greater than 1:1 (perfect match) SWR.



SWR is an abreviation of standing-wave ratio.   SWR on a transmission line in an antenna system represents the the ratio of foward to reflected voltage on the line.  A perfect 1:1 ration occurs when all parts of the antenna system are matched correctly to one another.
Written by: NJ2X, Michael Maher