ALAN Electronics Tectalk FM PMR 446, Service Manual

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Service Manual
4. ADJUSTMENT
4.1 Frequency synthesizer (PLL)
a) After connecting the power meter and dummy load (50 Ohms), join the
Internal antenna connection points of TECTALK FM with above equipment.
b) Check the voltage between TP & GND in digital volt meter.
c) Then set the low channel of Tectalk(FM) the lowest frequency.
d) After pressed PTT key of Tectalk(FM), trim VC1 for adjusting the
lowest frequency of Tx channel to DC 1.5V in the voltage of TP1.
e) After releasing the PTT key, And then check if the highest
frequency of Rx channel is within DC 2.0V in the voltage of TP1.
4.2 TRANSMITTER
a) Connect EUT & measure equipment according to block diagram below.
b) Connect DC 6.0V, voltage preset to EUT.
c) Connect "Power Meter" & "dummy load(50 Ohms internal connection points)".
d) Adjust Tx frequency according to trimming trimmer VC2.
e) Connect AF oscillator to MIC terminal for conform modulation degree.
f) Adjust the frequency of AF oscillator to 1kHz and adjust AF level
should be 60mV.
g) Checking oscilloscope and modulation meter. max.
Frequency deviation should be in +/-2.2 KHz.