Barry777
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Jan 15, 2010, 1:41 PM
Post #3 of 3
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Re: [techchris] Video head life in hours?
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Hi Chris, My revisitation of VCR servicing pretty much stemmed from my frustration with the DVD format, and seeing "disc error" one time too many, along with the general flimsiness and sensitivity to scratches of the actual DVD's. I remembered that VCR's never failed to work when working properly (did that make sense?) and that the older ones were more than a few esoteric LSI processor chips, one cheap motor and an ingenious array of plastic gears to allow the use of as few quality parts as possible. Another factor is that now I can afford the once-cost-prohibitive Sencore VC93 (I have 3 now), factory alignment tapes and the assortment of Tentel gauges required for factory-spec work (have 10 of those now). And being a professional Avionics Technician with a lifelong passion for electronics, I already had a dazzling array of test equipment including many scopes, counters, logic and signature analyzers, wow and flutter meters and - more recently - a couple nice video monitors with underscan and "blue only" functions for setting the pluge pattern, NTSC bars and to see the hidden timing and headswitching information. My main test gear arsenal is stacked 4 high and fully covers an 8 foot long shelf above the bench, with another Oscilloscope and Vectorscope resting on the bench surface itself. I knew I wanted to own some professional VCR's as they are more rugged and were designed for continuous heavy use, so first came a few JVC BR-7000's. Then I wanted something more fancy, so I got a couple JVC BR-S822U's (one required 44 tiny jumpers installed on the small CPU board mounted in the front panel to repair shipping damage from terrible packing). Then when I figured I was back up to snuff on the technical end, along came a Sony SLO-1800 which has become my favorite project because of the increased complexity of the tape path, the slightly better picture quality and the general romance associated with the Beta format in the VCR community. After many hours with the service manual and much experimentation, I finally did a successful tape path alignment on my first Beta machine and it works GREAT! On most tapes, you can adjust the tracking contol through its full range with only slight disturbance of the picture at the extremes. Interestingly, the alignment tape only seemed useful for the rough adjustments, with the final tweaks performed with several movies - though I did monitor the entrance and exit RF envelope with all tapes as it seemed to provide more information than the monitor screen. Finally, yesterday I did some work on the loading carriage and eliminated the sudden jerks caused by the shrinkage of the plastic inserts in the tracks. The entire machine is now tip-top. To answer your question about what to do with the Beta machines, well - mainly I just like to see my hard work pay off and watch the doggone thing :-) I have the SLO-1800 in my "professional" rack, with a cheaper Sanyo Beta machine in the entertainment system. I've started collectuing Beta movies and currently have around 300, with maybe a few more VHS tapes than that. One reason for the VCR's is that maybe I won't have to keep paying for cable TV if my aging wife should, God forbid, pass on before I do - but I think right now the real reason is to satisfy my craving for complex electronic work, which was probably triggered by the technical demands of my day job. I have 2 more Beta machines in the closet, one with no capstan or drum activity and another with servo lock issues - which I've recently learned could be as simple as misadjusted back tension. Man, Beta machines are weird compared to VHS! On a VHS machine, bad back tension just made for a jittery picture and that was pretty much it. Geez man, Beta machines are SO much pickier and critical. Capstan TILT adjustments? Wow! But I'm hooked now and can't resist the challenge. Cheers - Barry . . . Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html
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