Bit Error Rate (Ber) Test - Motorola ASTRO SPECTRA Service Manual

6-22 Radio Alignment Procedure: ASTRO Digital Spectra and Digital Spectra Plus Tuner Software
5. Left-click the PTT Toggle button on the screen to make the radio transmit. Wait
approximately 5 seconds until the deviation/voltage displayed on the analyzer stabilizes. The
screen indicates whether the radio is transmitting.
6. Adjust the deviation limit to within 0.158 to 0.163 Vac on the R-2670 (2.785 to 2.885 kHz).
The optimum setting is 0.160 Vac (2.83 kHz).
7. Repeat the above process for all frequencies.
8. Left-click the Program (Digital Spectra) or Program All (Digital Spectra Plus) button on the
screen to dekey the radio and save the tuned values.
9. Left-click the Close button on the screen to return to the Transmitter Alignments menu.
6.3.7

Bit Error Rate (BER) Test

This screen is used to test the Bit Error Rate (BER) of the radio's receiver at a desired frequency and
contains the following fields:
• Rx Frequency:
This field selects the Receive Frequency directly in MHz.
• Test Pattern:
This field selects the Digital test pattern — TIA. Choices are: Standard Tone Test Pattern
(framed 1011) and Standard Interface Test Pattern (CCITT V.52).
• Modulation Type:
This field represents the digital modulation type of the incoming signal on which BER is to
be calculated.
• Continuous Operation:
This field allows the user to make the BER test repeat indefinitely. A selection of Yes will
cause the radio to calculate BER on a continuous basis and update the results on this
screen after each integration time. A selection of No will cause the BER test to execute for
only one sample of the integration time and then update the display.
NOTE: When Continuous Operation = Yes, all fields will be grayed out while test is in
• Audio:
This field allows the user to select the audio output during a test. Selecting Internal will
cause the radio's built-in speaker to unmute to any signals at the desired frequency that are
present during the test. Selecting External will route the same signal to the radio's
accessory connector audio output. Selecting Mute will disable the audio output.
• Integration Time:
This field represents the amount of time over which the Bit Error Rate is to be calculated.
The range is from 0.360 to 91.8 seconds in increments of 0.360 seconds.
February 3, 2003
progress. They will be enabled when the test is complete, or if the STOP button is
pressed.
When Continuous Operation = No, a wait cursor will be displayed while the test is
in progress and return to normal when the test is done.
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