Azden 2000XT Guide

1.Adjustment Manual
Issue Y M D Azden Adjustment Standard Category
Y M D 33-543-01 (2000X ) Adjustment Manual No.
Power supply:3.0V
Channel and Fre uency List used on the adjustment
Channel Fre uency
42-01 638.125MHz
43-47 649.875MHz
45-47 661.875MHz
1. Adjustment of VCO
1) Set the channel to 42-01
2) Connect the DC voltmeter to P201
3) Confirm the DC voltmeter indicates 1.3V
4) Set the channel to 45-47 and confirm the voltage
is 2.1V on the DC voltmeter
2. Adjustment of the RF output power
1) Set the channel to CH43-47
2) Connect the power meter to CN201
3) Adjust the power to 50mW by VR201
4) Connect the spectrum analyzer to CN201
5) Confirm that the difference of the RF Level between carrier and spurious is
at least 40dB.
3. Adjustment of the transmitting frequency
1) Set the frequency to CH43-47
2) Connect the frequency counter to CN201
3) Adjust VC201 so that the frequency counter shows 649.875MHz
4. Confirm the tone fre uency and adjustment of the deviation level.
1)Connect the fre uency counter to TP101 and confirm the fre uency is 32.768kHz.
2)Connect TP102 and GND.
3)Connect the linear detector to CN201.
4)Adjust VR3 so that the deviation level is plus-minus 3.0kHz.
5. Adjustment of the AF modulation
1)Set SW201:OFF SW2:ON
2) Connect the RC Oscillator to P11(HO ).SHOR P10(COLD) and GND.
3) Set the oscillator output level -35dBu( he frequency is 1kHz)
4) Connect the AC voltmeter to P101.
5) Adjust the VR100 so that the voltmeter shows -17dBu.
6) Connect the linear detector to CN201.
7) Adjust VR202 so that the deviation level of AF& ONE is plus-minus 23kHz
8)Connect P102 and GND.Readjust the deviation level of ONE is plus-minus 3.0kHz.
9)Set the oscillator output level to -60dBu( he frequency is 1kHz)
10)Adjust VR2 so that the first AF Level indicator appears.
Adjusted
date

6. Confirming of the battery indicator
1) Supply 2.5V to the transmitter and cofirm that the battery status indicates 3 levels .
2) Supply 2.0V to the transmitter and cofirm that the first indicator is flashing.
7. Other confirming points
1) Set up the receiver for communication check
2) Connect the lavalier microphone to the transmitter and send
the audio to check whether it operates correctly
3) Make an impact on the body and check whether the unit does not
show any abnormal sound
5) Factory default conditions
[Power]:OFF, [Channel]:42-01,[Audio SW]:OFF,[Phantom Power]:OFF
Azden corp.

2.Voltage and current at RF part
1.Voltage and current at RF part
Low(CH42-01) Mid(CH43-47) High(CH45-47)
Vce 3.5V 3.5V 3.4
Ic 25mA 26mA 28mA
2.Description of main feature of circuit
(1)Stabilization of frequency
Oscillation method :PLL synthesized
The stabilization of this oscillation method relies on crystal oscillator performance.
Its accecting range is fre uency deviation plus-minus 10ppm or less,under -10 degree to +60 degree
temperature by using Tokyo Denpa made crystal oscillator.
(2)How to reduce the spurious radiation
In order to suppress the radiation,LC filter is positioned after current amplification part.
It is low passed filter which forms pie shape with third layered.
(3)Restriction of Audio modulation
In order to restrict audio modulation,diode limiter circuit(ZD101,ZD102) is put into
pre-emphasis circuit.