Item 5: Nominal Deviation - Ericsson EF738 Service Instructions Manual

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Item 5: Nominal Deviation

Purpose:

Checking and, if necessary, calibrating the nominal deviation of the transmitter

Test method:

Radio test set in TX mode

Input signal:

1kHz sine wave signal at 190mV

Measurement point:

At the antenna connector measured with a deviation meter

Limit:

±5.7kHz ±0.5dB (5.38 - 6.02 kHz)

Procedure:

1. Enable the compandor (TP-29:1)

2. Connect a 1kHz sine wave signal at 190mVRMS to ATMS (system connector)

3. Turn the transmitter on (TP-2:2)

4. Monitor RF peak deviation

5. If the deviation is outside the limits; adjust the deviation

6. Enter TP-27

7. Start the trimming by pressing M + #

8. Trim audio deviation to 5.38 - 6.02 kHz by pressing # and * to increase/decrease

the deviation

Allowed trim values are 2 to 29

Trim step size is 0.4dB per step

9. Press M + S to store the value

to ATMS (system connector)

RMS

Service Instructions

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