3
Notes:
·
An SWR reading will be different for different frequencies
(channels/bands). If you transmit on one band more often than any
other, select a channel within that band (e.g. UK or CEPT). If you
transmit on several bands, choose a frequency in the middle of the
range of channels you use. (For example, if you transmit on CEPT
and UK 40 channels, choose CEPT Channel 40, because it is as
near as midway as you can get)
·
If you use a CB that has sideband modes (SSB), do not select any
of these modes. (Use only AM for SWR measurements).
·
If you have an amateur radio, select the continuous wave (CW) or
tuning mode to check the SWR.
SWR Scales
The figure shown between the upper and lower scales on the meter (% REF
POWER) indicates the percentage of power that is wasted through reflection
of the signal from the antenna back into the antenna cable. For example, an
SWR reading of 1.5 also means that 4% of your signal power is lost. However,
96% of the radio power is more than enough for almost all applications.
Repeat Steps 1–5 for any other channel, band or frequency you want to get
an SWR reading for.
INTERPRETING SWR READINGS
An ideal SWR reading is 1.0, but this reading is usually possible only under
laboratory conditions or with a dummy load. Actual antenna installations have
higher readings. The information below will help you interpret the readings
you get.
SWR Efficiency Interpretation
1 to 1.5
Excellent
Antenna cable and the antenna length match the
transmitter’s output requirements almost perfectly
1.5 to 2.0
Very good Antenna, cable, and transmitter operate efficiently
2.0 to 3.0
Acceptable
Antenna, cable, and transmitter operate with some
loss. If possible, adjust your antenna or antenna
mounting system to improve
Above 3.0
Inefficient
Adjust your antenna or antenna mounting system to
improve efficiency. WARNING: Continued use is
likely to cause damage to your transmitter