Section 6. Repair
6-2
OUTPUT TESTS
Three output tests are provided to allow setting of the tone output levels. Cycle the unit's
power to exit the output tests.
Audio Test Mode
Depress the A + CLEAR keys while at the normal idle prompt (- ) to activate the tone
output test. The encoder will display the prompt “Audio” while in this test mode. The
encoder will close the tone relay and generate a sequence of three test tones at 2000 Hz, 1000
Hz, and 500 Hz (±0.1 Hz) at TB1 pins 3 and 4. Each tone lasts for 1.5 seconds and then
automatically switches to the next tone. The encoder continues to generate these tones until
the test is terminated by pressing the CLEAR key again.
The output levels of all microprocessor generated tone frequencies will be referenced to
these test tones. This test is also useful for checking that the de-emphasis jumper (JP10) is in
the correct position to ensure a reasonably flat modulation level across all of the audible
paging frequencies.
Binary Test Mode
The Binary test mode is similar to the Audio test, however, it is used for setting deviation for
signals from the digital modulation output. While at the normal idle prompt, press the B +
CLEAR keys to activate the digital circuitry tests. After pressing the two keys the prompt
“binArY” is displayed. The encoder will accept the keys shown in Table 6.
REPAIR-1
for
selecting test functions. The keys can be pressed in any order and repeated as many times as
needed. Press the CLEAR key to exit this test and return to the normal operating mode.
Table 6. REPAIR-1. Binary Test Functions
Key Prompt
Function
0
LOU.
Logic “0” output
1
HIGH
Logic '1' output
2
200
200 baud continuous preamble
(alternate 0/1)
3
300
300 baud preamble
5
512
512 baud preamble
6
600
600 baud preamble
7
1200
1200 baud preamble
8
2400
2400 baud preamble
