Item 7: Tx Data Deviation - Ericsson EF738 Service Manual

Item 7: TX Data Deviation

Purpose:
Checking and, if necessary, calibrating the TX data deviation of the transmitter
Test method:
Radio test set in TX mode
Input signal:
None
Measurement point:
At the antenna connector measured with a deviation meter
Limit:
±6.4kHz ±0.5dB (6.021 - 6.780 kHz)
Procedure:
1. Mute the TX audio path (TP-20:0)
2. Activate the TX Data (TP-23:1)
3. Turn the transmitter on (TP-2:2)
4. Monitor the TX data deviation
5. If the deviation is outside the limits; adjust the deviation
6. Enter TP-23
7. Start the trimming by pressing M + #
8. Trim TX Data Deviation to 6.021 - 6.780 kHz by pressing # and * to increase/
decrease the deviation
Allowed trim values are 2 to 13
Trim step size is 0.4dB per step
9. Press M + S to store the value
Service Instructions
17