Magnavox 27MDTR10S Service Manual

Also see for 27MDTR10S: Owner's manual

2-3-4 TD603MA6. Press CH DOWN button on the unit until the CTLwaveform has shifted from its original position (notthe position achieved in step 5, but the position ofCTL waveform in step 4) by approximately -2msec.Make sure that the envelope is simply attenuated(shrinks in height) once CTL waveform passes itsoriginal position and is further brought in the minusdirection.7. Set the Tracking Control Circuit to the center posi-tion by pressing CH UP button and then “ PLAY ”button on the unit.1-C. Checking/Adjustment of EnvelopeWaveformPurpose:To achieve a satisfactory picture and precise tracking.Symptom of Misalignment:If the envelope output is poor, noise will appear in thepicture. The tracking will then lose precision and theplayback picture will be distorted by any slight varia-tion of the Tracking Control Circuit.1. Connect the oscilloscope to TP1403 (ENV) on theMain CBA. Use TP1401 (RF-SW) as a trigger.2. Playback the Gray Scale on the Alignment Tape(VFMS0001H6). Set the Tracking Control Circuit tothe center position by pressing CH UP button andthen “ PLAY ” button on the unit. Adjust the heightof Guide Rollers [2] and [3] (Fig. M3, Page 2-3-3)watching the oscilloscope display so that the enve-lope becomes as flat as possible. To do this adjust-ment, turn the top of the Guide Roller with theGuide Roller Adj. Screwdriver.3. If the envelope is as shown in Fig. M7, adjust theheight of Guide Roller [2] (Refer to Fig. M3) so thatthe waveform looks like the one shown in Fig. M9.4. If the envelope is as shown in Fig. M8, adjust theheight of Guide Roller [3] (Refer to Fig. M3) so thatthe waveform looks like the one shown in Fig. M9.5. When Guide Rollers [2] and [3] (Refer to Fig.M3)are aligned properly, there is no envelope dropeither at the beginning or end of track as shown inFig. M9.Note: Upon completion of the adjustment of GuideRollers [2] and [3] (Refer to Fig. M3), check the XValue by pushing the CH UP or DOWN buttons alter-nately, to check the symmetry of the envelope. Checkthe number of pushes to ensure center position. Thenumber of pushes CH UP button to achieve 1/2 levelof envelope should match the number of pushes CHDOWN button from center. If required, redo the “XValue Alignment.”1-D. Azimuth Alignment of Audio/Control/Erase HeadPurpose:To correct the Azimuth alignment so that the Audio/Control/Erase Head meets tape tracks properly.Symptom of Misalignment:If the position of the Audio/Control/Erase Head is notproperly aligned, the Audio S/N Ratio or FrequencyResponse will be poor.1. Connect the oscilloscope to the audio output jackon the rear side of the deck.2. Playback the alignment tape (VFMS0001H6) andconfirm that the audio signal output level is 8kHz.3. Adjust Azimuth Adj. Screw so that the output levelon the AC Voltmeter or the waveform on the oscil-loscope is at maximum. (Fig. M6)Dropping envelope level at the beginning of track.Fig. M7Dropping envelope level at the end of track.Fig. M8Envelope is adjusted properly. (No envelope drop)Fig. M9