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R O U B L E S H O O T I N G
cables, splitters, the power inserter, line amplifiers, or down
converters, and that none of these components are outside their
electrical parameter specifications.
•
Verify that patient coverage has been met, and that antenna
spacing is correct.
•
Verify the patient transmitter function. For example, check if the
transmitter has the proper RF output power, if it is transmitting
on the correct channel, and that battery voltage meets the
operating voltage of the transmitter.
If squelch persists, you can lower the antenna system gain, but do
not adjust the gain lower than the minimum required antenna
system gain specification. Lowering the antenna system gain should
reduce the amount of squelching present in the antenna system.
After the antenna system gain is lowered, survey the coverage area
with the transmitter on your body to verify proper patient coverage.
Use of RF Performance Statistics
The following provide additional means for investigating and
analyzing squelch and RF transmission performance.
SQUELCH STATS is a hidden key in the ECG menu. It presents a
display (and menu) of incidents of squelch that have been recorded
in the module memory.
A sample display of the alternate zone with the statistics filled in is
shown in
The columns of data show the following:
•
Number of 120 Hz samples missed.
•
Date when the episode of squelch occurred.
•
Time when the first missed sample occurred.
The displayed data is organized into pages of 20 occurrences each.
The statistics kept are in volatile memory and are erased upon cold
boot of the module. The maximum count displayed will be 9999
samples (but could in reality be an infinite duration of squelch). Up
to 480 episodes of squelch can be stored. Beginning with the 480th
episode, only the most recent 480 are stored.
Figure 5-5 Example of squelch statistics display
P
123
6/15
10:37
872
6/16
1:10
23
6/19
14:17
54
6/27
15:34
A
2
6/15
11:39
2
6/16
4:10
112
6/19
14:19
245
6/30
15:39
G
25
6/15
13:45
2
6/16
9:11
222
6/20
14:25
8
6/30
16:45
E
345
6/15
16:30
5
6/16
12:31
98
6/23
14:26
35
6/30
17:30
1
92
6/15
21:05
578
6/18
23:56
34
6/26
14:34
45
6/30
21:21
