BIRD AT-400 Antenna Tester AT-400, Operator'S Manual, Page: 31 / 57

Measure Match
19
Antenna manufacturers often use VSWR for specifications.
Match Efficiency is popular for testing because it is easy to
determine a good match versus a bad match. For example a
system with a VSWR of 1.50 would show -13.98 dB Return
Loss and 96% Match Efficiency.
Auto Scale vs. Manual Scale
In swept mode Auto Scaling sets the measurement unit scale
to make the trace easier to read. However, if you plan to look
at the size or shape of traces for quick comparisons, it might
be more meaningful to set a standard scale. Remember that
it is possible to set the scale manually so the information is
not on the display at all.
Figure 6
Auto Scaling
Swept
Frequency
Mode
Figure 7
Manual
Scaling Swept
Frequency
Mode
Swept
Freq Single
Freq Util Test
VSWR
1.5
1.2
65.00 MHz 520.00
*
1.35
260.00 MHz
Field
Str
VSWR
2.0
1.0
65.00 MHz 520.00
*
1.35
260.00 MHz
Swept
Freq Single
Freq Util Test Field
Str