Ericsson MGM 450, Руководство по обслуживанию

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WARNING: To prevent damage to the radio, avoid keying the radio for periods longer than 1 minute. Allow a
5 minute cool down period after keying the radio for 1 minute.
7. Check the power output at the lowest, middle and highest transmit channels and adjust RV2 if necessary, to
maintain 40 watts at all frequencies.
8. Press PTT and adjust TC11 for the correct frequency.
DCS Modulation Balance Adjustment
1. Connect test equipment to the radio as shown in the Test Equipment Setup.
2. Set the CHANNEL selector to a transmit channel which has a DCS code pre-programmed (should be
mid-frequency channel).
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WARNING: The power attenuator must have enough attenuation to prevent damage to the deviation meter.
3. Press the PTT switch.
4. Observe the waveform on the oscilloscope and compare with that shown in Figure 6.
5. Adjust RV5 and TC12 to achieve the proper wave form. Release the PTT switch.
6. Replace the deviation meter with a frequency counter.
7. Set the CHANNEL selector to the highest transmit channel. Ensure that this channel has no DCS or CTCSS
tones pre-programmed.
8. Press PTT switch. Adjust TC11 for the correct transmit frequency. Release the PTT.
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NOTE: TC12 should not be allowed to be placed at the maximum capacitance position, if TC12 should be found
to be at the maximum capacitance position, place TC12 at the typical position and adjust RV5 for the proper
wave form.
DCS Modulation Wave Form
30°
TC12 Maximum capacitance position and typical position
MONOGRAM SERIES LBI-38865
ALIGNMENT PROCEDURE
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Nov. 94