Radio Shack TRC-446 - Manual (Page 10)

10
STANDING WAVE RATIO GUIDELINES
The ideal standing wave ratio (SWR) is 1:1, or a meter reading of 1 on the SWR
meter's top scale. This reading, however, can only be obtained under laboratory con-
ditions. A SWR ratio of 1.5:1 to 2:1 is excellent for most mobile CB antenna applica-
tions. This chart helps you interpret the different readings you might see.
Standing Wave Ratio Performance
Prolonged exposure to salt spray, humidity, weather-induced corrosion, or vehicle vi-
bration can cause antenna performance to degrade with a subsequent rise in the
SWR. Anytime you notice that the SWR reading is greater than 3:1, check the condi-
tion of the antenna, the antenna cable and all antenna connectors and hardware.
Ratio Rating Evaluation
1:1 – 1.5:1 Superior Perfect match between the an-
tenna/cable and the RF output of
the CB.
1.5:1 – 2:1 Excellent The antenna/cable system is an
outstanding match to the trans-
mitter’s RF output. Ideal for most
CB installations.
2:1 – 3:1 Good The antenna/cable system will
perform to specification under
most normal conditions.
Higher than
3.1:1
Inefficient Indicates a need to inspect the
system, the mounting of the
antenna and all pertinent hard-
ware.
21-1574.fm Page 10 Thursday, May 13, 1999 4:03 PM