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It was helpful to get schematic with waveforms in important points and lot of service information. Manual is good quality, fast delivered. Of course it is hardcopy of paper one with all its disadvantages.
I want to give you a real heads-up for your desire to enable such people as I to acquire the information I need to maintain the older types of equipment such as this Akai HXA351W. You do a swell job with all the processes you have to perform so I can have a legible, thus usable
document which does not send me crazy trying to figure out the blurry text of a bad copy.
Very well done, Thomas.
This manual is very well presented and after printing out looks about as close to an original as I think you can get. The quality is second to none.
The content of the manual is comprehensive and I think it would be well suited to an audio repair professional which I'm not but I did find it very informative and helpful.
The cost of the manual is more than covered by the money I'll save when I change the keep memory battery now I have the relavant info.
Very pleased with my purchase and can recommend it wholeheartedly as I can other manuals I've downloaded from this site.
Complete manual including mechanical part in good pdf quality. Shaded greys of the pcb due to pdf not perfect but usable.
Nice pdf file of the manual sent promptly. Thanks.
2.13.3 Linearity adjustment The following flowchart shows the linearity check/adjustment procedure.
Connect an oscilloscope (CH: + Slope) and, while triggering it with the HID signal, observe the ENV OUT waveform.
PB switching point adjustment
The following flowchart shows the PB switching point adjustment procedure. Load the alignment tape.
Play the alignment tape, then set âATFâ (Auto Tracking Find) in âDeck Controllerâ of the SSS Software to ON. (Note 3)
The âPB Switching Pointâ in the Adjustment Utility of the SSS software is adjusted automatically.
Ensure that the ENV OUT waveform is linear and parallel, without a noticeable drop or variation in the overall level. If the waveform linearity is poor or there is a noticeable drop in level, adjust the guide roller by turning it with the roller driver.
2.13.5 Error rate adjustment The following flowchart shows the error rate adjustment procedure.
Record for about 5 minutes. (Note 6)
Set âATFâ (Auto Tracking Find) to OFF using âDeck Controllerâ of the SSS Software (Note 4). Observe the ENV OUT waveform to confirm that the overall waveform balance and linearity levels vary in accordance with the tracking variation as shown in Fig. 2-18-3. Repeat above steps as required. Is the PB ENV waveform ideally stable and does it vary ideally according to the tracking variation?
While playing the recorded signal, adjust âVCO Center Frequency (ME SP)â or âVCO Center Frequency (ME LP)â in âDeck Sectionâ of the Adjustment Utility. To adjust VCO Center Frequency (ME SP) : Set Viterbi OFF. To adjust VCO Center Frequency (ME LP) : Set Viterbi ON.
Yes The linearity adjustment is complete if the PB ENV waveform is ideally stable and varies ideally according to the tracking variation. To close, play a prerecorded tape and check the audio and video.
Is the obtained error rate minimum (almost the typical value)?
The error rate adjustment is complete when the minimum error rate which is no higher than the typical value is obtained. (Note 5)
Note 5 : â¢ The âtypical valueâ refers to the following: CH1 or CH2: < 498.; with Viterbi OFF. Inter-channel difference: < 10 times between CH1 and CH2. Note 6 : â¢ It is desirable to use a brand-new tape or an unused section of tape. This is to assure the adjustment reliability because using a damaged tape increases the error rate.
PB ENV waveform
Adjust variation in the parallelism
Fig. 2-18-4 PB ENV Waveform Note 3 : â¢ The VHS section has an A/C head, and the first tracking position can be locked using the CTL pulse and drum FF when AT is off. Therefore, the linearity of the VHS section can usually be adjusted with AT off. However, this adjustment method is not available with the DV section, which does not have the A/C head. If ATF is turned off, the DV section performs tracking only of the speed system. Therefore, as time passes, the servo will be lost and the linearity adjustment will become difficult. Note 4 : â¢ Since the speed servo function is active when ATF is off, there will be no problem even if the DVC ATF function is off, provided that it is for a few minutes.
Error rate measuring method
It is not necessary to use the error rate jig (YTU93083) or a frequency counter. The Service Support System Software displays the error rates of video CH1, CH2 and totals. When measuring the error rate of a channel, be sure to total the values of the video and the audio errors.