Park Air T6M, Руководство пользователя, Страница: 52 / 70

Receiver Sensitivity Check
To check the base station's receiver sensitivity carry out the following procedure:
(1) Isolate power from the base station and connect the test equipment as shown below.
(2) Reconnect the power and ensure the base station's rear panel Power switch is set to on.
(3) Adjust the signal generator to operate at 118.000 MHz with an RF level of -100 dBm and a
1 kHz tone modulated at 30%.
(4) At the base station's front panel press the squelch (SQL) button. Check that the display
shows an ‘S’ and a number between 1 and 20. This number is the squelch level setting.
(5) Adjust the squelch level, by pressing the VOL s and VOL t buttons, until the display shows a
level of 2.
(6) Adjust the volume control until a reference reading (approximately mid-scale) is shown in the
AF wattmeter. Note the reading in dB.
(7) Set the signal generator's modulation to off.
(8) Increase the sensitivity of the AF wattmeter until a reading is obtained. Note the reading in
dB.
(9) Check that the difference in readings noted in steps (6) and (8) are not less than 10 dB.
(10) Repeat steps (3) to (9) for test frequencies of 127.500 MHz and 136.975 MHz.
(11) On completion, switch off the base station and disconnect the test equipment. Restore the
base station ready for operational use.
Battery Replacement
An optional battery can be fitted to act as a backup supply if the mains supply fails. The lead acid battery
is fitted in the position shown in Figure 8.
The battery should be replaced after a period of time that depends on usage. Table 10 details the
replacement period according to usage.
T6M Base Station User Guide
Page 52
Receiver Sensitivity Test - Test Equipment Connection