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5. Applications
5.1. Antennas
5.1.1. Checking the antenna
It is a good idea to check an antenna before connecting it to the receiving or
transmitting equipment. The
SWR graph
mode is right for this purpose:
The above picture shows SWR graph of the vertical VHF antenna connected via the 40
m (131 ft) cable. The operating frequency is 146.2 MHz. The SWR at this frequency is
about 1.1, which is acceptable.
The next screen shot shows SWR graph of the simple dipole antenna with desired
operating frequency of 14.1 MHz:
The actual resonant frequency is about 13.4 MHz, which if too far from the desired
one. The SWR at 14.1 MHz is about 2.5, which is not acceptable in most cases.
5.1.2. Adjusting the antenna
When the measurement diagnoses that the antenna is off the desired frequency, the
analyzer can help in adjusting it.
