Ericsson EDACS MDX Instrukcja Operatora Pobierz pdf (Strona 17)

2. With the Low Frequency value highlighted, press F4 Tx On to key

the transmitter.

3. The 1 kHz tone will be summed with a 75 Hz low speed data signal.

4. Measure the deviation. The Modulation Monitor should be set for 15

kHz low pass filter and no high pass filter.

5. Increment or decrement the value (hex or digital) until the deviation

specifiations are met. See Table 4. The deviation test window is 0.20

kHz wide. Each step is typically 0.14 kHz, depending on the VCO

modulation sensitivity.

Table 4 - TX Deviation Specifications

FREQUENCY DEVIATION (kHz)

TX Low

4.5 ±0.1

TX Mid

4.5 ±0.1

TX High

3.6 ±0.1

TX Low Talkaround

4.5 ±0.1

TX Mid Talkaround

4.5 ±0.1

TX High Talkaround

3.6 ±0.1

6. Press F4 Tx Off to key the transmitter.

NOTE

The MIC HI input line to the PCS is also the RX DATA line from

the computer. To allow simultaneous communication with the

computer while feeding in a 1 kHz tone, the audio generator

impedance must be 600 ohms or greater. Insert a resistor in series

with the generator output if necessary, i.e. a 560 ohm resistor

when using a 50 ohm generator. Also, higher audio signal levels

exceeding 200 mV rms may confuse the radio as being data.

LBI-38898

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Ericsson EDACS MDX Instrukcja Operatora Strona 17