Service Manual VHF (136-174MHz) Information
483
Description of Normal Situations:
[1] Output voltage at Q9019 PIN3: about 4.95V.
[2] Output voltage at U605 PIN4 or input voltage at Q9019 PIN4: about 5V.
[3] Vbe: about 0.74V; Vce: about 2.5V (in the case of no signal reception).
[4] For Q9018, Vbe: about 0.76V; Vce: about 0.95V;
for Q9017, Vbe: about 0.7V; Vce: 0.85V (in the case of no signal reception).
[5] Cut off the front-end circuit, and input a 44.85MHz IF signal at TP402 to test IF sensitivity.
Normally, the IF sensitivity is -109dBm.
[6] Frequency of Q403: 47.1/42.6MHz.
[7] Frequency of L411: 18MHz.
[8] Input a -30dBm RF signal at the antenna connector and test at TP9004. Normally, gain>10dB,
output signal>-20dBm.
[9] Input a -30dBm RF signal at the antenna connector and test at R9005 (do not cut off the back-end
circuit). Normally, gain>1dB, output signal>-29dBm.
[10] Signal frequency: RF-IF, signal amplitude>2dBm.
[11] For input of -80dBm signal at L9022, gain>25dB, output signal>-55dBm;
for input of -30dBm signal, output signal<-20dBm.
[12] The input signal at the antenna connector, with standard tuning information (AF=1 KHz, FM=3
KHz), is -47dBm.
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