Bird Technologies AT-500-Manual - Manual (Page 45)

Measure Match
27
1. Press the MENU key.
2. Press the SWEPT FREQ key.
3. Press the SWEEP TYPE key.
4. Do one of the following, depending on desired
mode:
z
Press SINGLE HOLD key.
Note:
HOLD will be displayed.
z Press CONT key.
Note:
The tester begins sweeping.
Saving a Trace
The AT-500 can store up to 12 traces. A saved trace can be
used to evaluate long term antenna performance, compare
performance under different conditions or for comparison
to another antenna. A saved trace is also a powerful tool in
limit testing (more about limit testing later in this sec-
tion). The information can later be uploaded to a PC using
optional interface software and the serial port. Traces are
stored in nonvolatile memory so they are not lost when the
Antenna Tester is turned off.
Since the reflection coefficient is the information actually
saved when saving a trace, and everything else is calcu-
lated from that, you have some flexibility when using the
trace for comparison. For example, if you save a trace dis-
played in VSWR, you can compare it to a trace displayed
in %Match. You can also change the frequency band of
the new trace to effectively zoom in on a particular sec-
tion of the saved trace. This may be helpful in pinpoint-
ing a problem area in a failed limit test.