User's Guide

Page 9
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Notes for Setting Up the Transceiver
The following notes should be read before setting up the transceiver. They advise on the special
frequency display when using 8.33 kHz channel spacing, and give guidance on the optimum line level
settings. Note that for operation in the United States of America, this equipment is certified only for
operation using 25 kHz channel spacing.
Front Panel Display for 25 kHz and 8.33 kHz Channel Spacing
When setting the operating frequency of the transceiver and 8.33 kHz channel spacing is selected, the
displayed frequency differs from the actual channel frequency. Table 3 shows the pattern used for
25 kHz and 8.33 kHz spaced channel frequencies from 118.000 MHz to 118.141 MHz. The pattern is the
same for any frequency within the transceiver's frequency range. The display conforms to ICAO
convention for 8.33 kHz operation.
Input Line Level Settings
The input line level setting displayed on the front panel is equivalent to the average speech level with a
peak-to-average ratio of 13 dB. This corresponds to the level specified for the lines.
When testing the transceiver using a sine wave, the line input level should be set to 10 dB above the line
level setting. The VOGAD and mute thresholds are pre-set at 10 dB and 15 dB respectively below the
line level setting.
Table 4 shows the relationship between the input line level, VOGAD threshold and mute threshold.
Table 3 25 kHz and 8.33 kHz Channel Spacing Displays
Actual Frequency
(to 4 decimal places)
Channel
Spacing
Displayed Frequency
at Transceiver's Front Panel
118.0000 MHz
118.0000 MHz
118.0083 MHz
118.0166 MHz
118.0250 MHz
118.0250 MHz
118.0333 MHz
118.0416 MHz
118.0500 MHz
118.0500 MHz
118.0583 MHz
118.0666 MHz
118.0750 MHz
118.0750 MHz
118.0833 MHz
118.0916 MHz
118.1000 MHz
118.1000 MHz
118.1083 MHz
118.1166 MHz
118.1250 MHz
118.1250 MHz
118.1333 MHz
118.1416 MHz
25 kHz
8.33 kHz
8.33 kHz
8.33 kHz
25 kHz
8.33 kHz
8.33 kHz
8.33 kHz
25 kHz
8.33 kHz
8.33 kHz
8.33 kHz
25 kHz
8.33 kHz
8.33 kHz
8.33 kHz
25 kHz
8.33 kHz
8.33 kHz
8.33 kHz
25 kHz
8.33 kHz
8.33 kHz
8.33 kHz
118.000 MHz
118.005 MHz
118.010 MHz
118.015 MHz
118.025 MHz
118.030 MHz
118.035 MHz
118.040 MHz
118.050 MHz
118.055 MHz
118.060 MHz
118.065 MHz
118.075 MHz
118.080 MHz
118.085 MHz
118.090 MHz
118.100 MHz
118.105 MHz
118.110 MHz
118.115 MHz
118.125 MHz
118.130 MHz
118.135 MHz
118.140 MHz