Motorola EP450 service manual Auto Tune, Rssi System Level Tuning

Radio Alignment Procedures: Receiver Tuning 5-13

3.Set softpot to its maximum value to mute the radio.

4.Adjust the softpot value by using the slider, keying in the edit box or using the spin controls. Press ENTER to confirm the selection or use the spin controls. Do this until the radio is totally unmuted. Verify the squelch closing by inputting a signal level of 4 dB lower than that of the 10 dB SINAD level.

5.Repeat Steps 2 through 4 of Manual Squelch Tuning, for frequency points F2-F7.

6.Press Program to commit the softpot values into the radio.

7.Exit the Squelch Tuning function.

5.5.2.2Auto Tune

Note: Proceed with caution since this procedure automatically programs the softpot value into your radio.

When you press the Auto Tune button, the radio automatically returns an optimum squelch value.

After you press the button, the radio may need time to produce an optimal setting for the squelch attenuation. The following steps describe the auto tune process:

1.Select current frequency point (F1 being the first), then press Auto Tune.

2.Repeat Steps 3-4 of the Manual Squelch Tuning section for frequency points F2-F7.

Note: Auto Tune will automatically update your radio’s codeplug. Please be careful when using it.

5.5.3RSSI System Level Tuning

Figure 5-11. RSSI Tuning

1.Under the Rx Align menu, select RSSI Tuning (Figure 5-11).

2.Inject an on channel signal to the radio at -47 dBm at the frequency listed. Modulate the signal with a 1 kHz tone at 60% deviation (3 kHz) to verify that the radio is receiving the desired fre- quency. RSSI tuning is only done at 25 kHz channel spacing.

3.Change the level to the defined dBm level in the softpot box. (-115 dBm or -105 dBm).

4.Press the Update button for the soft spot to be tuned to the RSSI value correlating to the applied level. The programmed RSSI value will be displayed.

HKLN4215A December 3, 2003