Text preview for : MANUAL SERVICE MX5203MS 18.pdf part of POLYTRON ( INDONESIA ) MX5203MS It used STV2286H , AN5891K , TDA8174 , STB9NK70Z-1 Complete Service Manual in RAR file type.sent by [email protected]
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Service Manual BML Myanmar
PT.Hartono Istana Teknologi
V.
TRAP 34.4 Mc ADJUSTMENT 1. Set the circuit as following figure :
Vcc (+8V)
TUNER IF IF AMP IC 301
C 309 5 1K
EXT. AGC
HBDC Modul
13 GERMANIUM DIODE 1K
C 505
SWEMAR +14VDC POWER SUPLAY LBO
IN
2. 3. 4. 5.
Set system on NTSC, and short Pin 4 of EA301 to ground. Ensure setting is on (not standby). Adjust Ext. AGC until the level of sinus signal is maximum without distortion. Adjust Trap 34.4 Mc (Ldc-301) of HBDC modul to obtain minimum DIP (smallest signal level) or until we get signal in the HBDC modul as following curve signal :
36.5Mc
38.9Mc
33.4Mc 34.4Mc
41.4Mc
Figure : IF curve of NTSC system IF Measurement Standard for NTSC system : Freq : 36.5MHz = 0dB (70dB) 38.9MHz = 6dB (5 - 7dB) 34.4MHz = 20dB (18-22dB)
note : HBDC modul no need to adjust if the circuit use SAW Filter MIF 389A ( Trap 34,4M on fixed Condition.
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