Hytera PT580, Service Manual, Page: 28 / 104

Service Manual
26
Description:
[1] The I/Q signals detected by the oscilloscope are modulation signals above 100mV.
[2] Apply -40dBm dot-frequency signal at the RF antenna connector (the -40dBm dot-frequency signal
will be applied at the antenna connector for the following signal amplitude detections unless
otherwise specified), and the amplitude of the signal at Pin5 of U4103 is -40~-50dBm when the
receiver is working.
[3] If the signal amplitude is normal, Pin4=0.3V, Pin6=3.3V.
[4] The normal amplitude range is -40~-55dBm.
[5] The amplitude of the output signal at U5001 should be larger than that of the input signal. The
normal range is -30~-40dBm.
[6] The normal voltage for U5001 is 3V.
[7] U5002 outputs 73.35MHz signal. The normal amplitude range is -50~-65dBm.
[8] The normal voltage for U5002 is 3V.
[9] Z5003 is the IF filter. The insertion loss should be less than 4dB, and the amplitude of the output
signal is -50~-70dBm.
[10] The amplitude of the output signal at Q5001 (IF amplifier) is -40~-55dBm, and should be larger than
that at Z5003.
[11] The normal voltage for Q5001 is 3V.
[12] Apply -40dBm Tetra signal at the antenna connector, and check whether I/Q signal is available at
TP5001 and TP5002 via an oscilloscope.
[13] The normal amplitude range is -10~0dBm.