JVC HM-DH30000U Service Manual

Also see for HM-DH30000U - D-VHS HDTV Digital Recorder: Instructions Service manual

Contents

3-4Note:• After adjusting, always perform the confirmation andre-adjustment of the item 3.4.1.Fig. 3-3-3b REC color (colour) levelV. rateSpecifiedvalue (G)(7) Set the VCR to the EVR mode by transmitting the code(F1) from the Jig RCU.(8) Set the EVR address to (F2) by transmitting the code (F3)from the Jig RCU.(9) Transmit the code (F4) from the Jig RCU to adjust so thatthe higher level channel becomes the specified value (G)of the note "B" level as shown in Fig. 3-3-3b. (Adjust be-fore recording, then confirm it by playing back.)(10) After adjustment, record the signal (A3) then playing itback again. At this time, confirm that there is no invert-ing phenomenon or noise appearing on the playbackscreen.(11) Release the EVR mode of the VCR by transmitting thecode (F1) from the Jig RCU again. (When the EVR modeis released, the adjusted data is memorized.)(12) Repeat steps (3) to (11) in the mode (B2).3.3.4 Video EQ (Frequency response)Signal (A1) • Ext. S-input(A2) • Video sweep signalMode (B1) • S-VHS SP(B2) • S-VHS EP(B3) • Picture Control / Smart PictureREC : Normal / NaturalPB : Edit / DistinctEquipment (C) • OscilloscopeMeasuring point (D1) • Y OUT terminal (75Ø terminated)Frequency marker(D2) • 3.58 [MHz]External trigger (E) • TP111 (D.FF)EVR mode (F1) • Jig code “57”EVR address (F2) • A : 03(F3) • Jig code “20” and “23”(F4) • Jig code “18” or “19” (Channel +/-)Specified value (G) • SP: 3.2 ± 0.2 div. (–2 ± 0.5 dB)• EP: 2.8 ± 0.2 div. (–3 ± 0.5 dB)Adjustment tool (H) • Jig RCU [PTU94023B](1) Apply the external trigger signal to D.FF (E) to observethe Y OUT waveform at the measuring point (D1).(2) Record the signal (A2) in the mode (B1), and play backthe recorded signal.(3) Set the VCR to the manual tracking mode.(4) Set the VCR to the EVR mode by transmitting the code(F1) from the Jig RCU.(5) Set the EVR address to (F2) by transmitting the code (F3)from the Jig RCU.(6) Set the slope of the oscilloscope to the channel havinghigher (D2) marker level of the Y OUT waveform [signal(A2)]. Then set the 100 kHz marker level to the “4” scaleon the oscilloscope. In this condition, transmit the code(F4) from the Jig RCU to adjust so that the (D2) markerlevel reaches the specified value (G).3.4 Audio circuitNotes:• This adjustment should be done after the “REC color(colour) level adjustment” for the video circuit hasbeen completed.• GND (Ground) should be taken from the Tuner shieldcase.Signal (A1) • Ext. input(A2) • Audio: No signal(A3) • Video: Color (colour) bar signal [NTSC]Mode (B) • S-VHS EP• TBC: OFFEquipment (C) • OscilloscopeMeasuring point (D) • TP2253 (A. PB-FM) [Main board]External trigger (E) • TP111 (D.FF)EVR mode (F1) • Jig code “57”EVR address (F2) • A : 30(F3) • Jig code “23” and “20”(F4) • Jig code “18” or “19” (Channel +/-)Specified value (G1) • 500 ± 100 mVp-p(G2) • More than 350 mVp-pAdjustment tool (H) • Jig RCU [PTU94023B](1) Apply the external trigger signal to D.FF (E) to observethe Audio PB FM waveform at the measuring point (D).(2) Record the signal (A3) with no audio signal input in themode (B), and play back the recorded signal.(3) Set the VCR to the manual tracking mode.3.4.1 Audio REC FM3.3.5 Auto picture initial settingSignal (A1) • Ext. input(A2) • Video: Optional(A3) • VHS tapeMode (B1) • VHS(B2) • EE ¥ Auto adjust (SP/EP REC ¥ PB)Adjustment part (F) • Jig code “58”Specified value (G) • STOP modeAdjustment tool (H) • Jig RCU [PTU94023B](1) Insert the cassette tape (A3) to set the mode (B1).(2) Set the VCR to the Auto adjust mode by transmitting thecode (F) from the Jig RCU. When the VCR enters thestop mode, the adjustment is completed. When the VCRenters the eject mode, repeat steps (1) to (2) again.(7) Release the EVR mode of the VCR by transmitting thecode (F1) from the Jig RCU again. (When the EVR modeis released, the adjusted data is memorized.)(8) Repeat steps (2) to (7) in the mode (B2).100 kHzFour scale 1 MHz 2 MHz Frequencymarker (D2)Specifiedvalue (G)5 MHzV. rateScale 4(4 div.)Fig. 3-3-4a Video EQ (Frequency Response)