EEVblog #907 - RETRO Teardown: Sony Video Walkman - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: August 03, 2016, 04:54:51 am
content: Rocking straight out of 1989, what makes the Sony GV-9E a marvel of engineering? Yet ultimately a flop.Manual:https://docs.sony.com/release/GV9.pdf

author: bktemp
author_rank: Super Contributor
timestamp: August 03, 2016, 06:00:30 am
content: The part with the large round metal can at 16:40 is a saw filter. If you cut one open, they have an interesting looking pattern on the filter element.Here is a datasheet for this and other models:http://www.datasheetarchive.com/dl/Scans-067/DSA2IH00210379.pdf

author: German_EE
author_rank: Super Contributor
timestamp: August 03, 2016, 07:56:12 am
content: That was fun, thanks for this one Dave. The transport mechanism for a VCR is remarkably complex and one tiny error can result in damaged tapes. When there was a problem one trick used by repair engineers was to videotape a good transport in operation then do the same with the broken one. Playing it all back in slow motion sometimes revealed the fault.bktemp beat me to the punch with the SAW filter, they are used in the TV receiver after the first mixer and normally operate at low VHF frequencies, say 45 MHz.

author: viperidae
author_rank: Frequent Contributor
timestamp: August 03, 2016, 10:41:32 am
content: The download link seems to be a bit bung, the file is only 24.4mbI went to watch it on the train on the way to work and it cut it after a few minutes

author: dr.diesel
author_rank: Super Contributor
timestamp: August 03, 2016, 12:23:08 pm
content: My dad bought one of these in the early 90s, as a very young engineer to be I was amazing at all the intricate small moving parts in the thing. Now the sight of it brings back memories of my brother and I watching movies on the thing (both over 6') crammed in the back of sedan full of luggage on a 12 hour drive to see Grandma. I'm pretty sure my dad's in the Guinness book for the world's largest bladder.My dad still has it and it still works.

author: SL4P
author_rank: Super Contributor
timestamp: August 03, 2016, 12:25:08 pm
content: Dave,You seemed to be enchanted by the tape threading mechanism...There's quite a lot involved if you get the chance to read back in time.For example, the different wrap patterns of VHS vs Beta, and consideration of tape speed vs drum speed to optimise the head-to-tape speed... all of course entangled with line rates, PAL, NTSC and the other variables.Then you get into the RF element of video recording... that Walkman is a video8 deck (effectively low-band), which was later complemented by Hi8 (high band), and eventually D8 (digital).Also, those pin micro switches also detected the type of cassette (metal/oxide etc) inserted, not just write protect status.There was an amazing amount of technology jammed in those consumer and prosumer gadgets. Digital almost made it 'easy'!

author: R_Gtx
author_rank: Regular Contributor
timestamp: August 03, 2016, 02:20:53 pm
content: Dave should really acquire aNagra VPR-5portable C-format video recorder for teardown, released circa 1983 (approx £25,000), this was truly one of the most gorgeous pieces of professional equipment ever manufactured.

author: N2IXK
author_rank: Frequent Contributor
timestamp: August 03, 2016, 05:14:50 pm
content: Nice teardown! Spent the early part of my electronics career working on this kind of stuff.You should pull the video head drum assembly out and tear it down. There is a lot of interesting engineering inside, including a 3 phase brushless motor, multiple hall effect sensors for motor commutation and servo feedback, a multiple winding rotary RF transformer to get signals to/from the rotating video heads, and a bunch of finely machined components and bearings.If you like the tape loading mechanism here (which is very VHS-like), you really should check out a Betamax or U-Matic transport sometime. A much more convoluted tape path involving a loading/guide ring that completely encircles the head drum.

author: nctnico
author_rank: Super Contributor
timestamp: August 03, 2016, 05:52:40 pm
content: Things like this make me feela) oldb) happy because all the tablet goodies we've seen on Star Trek back in those days can now be bought in a store around the corner.

author: max_torque
author_rank: Super Contributor
timestamp: August 03, 2016, 06:40:21 pm
content: I guess portable playback devices like this were obsoleted by portable recording devices, ie camcorders etc! For most people, it's much more useful to be able to record video on the move, rather than watch it on the move. The consumer demand for camcorders probably just meant companies like SONY focused their dev teams on those, much higher volume, products, and that is what killed these portble playback devices quite quickly!

author: SeanB
author_rank: Super Contributor
timestamp: August 03, 2016, 06:50:17 pm
content: Funny enough I bought a Panasonic MS50 camcorder recently on auction for $5. 2 of the 4 Panasonic batteries it came with were leaking that lovely blue NiCd death so went straight to the bin, along with the RF converter and most of the cabling. It might still work, but the viewfinder is dead, and this probably is terminal capacitor failure, as it is the right age to have those early miniature electrolytics inside that are so problematic.Charger still works, of course, but I suspect the remaining 2 battery packs are close to dead. Came in a nice hardshell case, with the usual rotten foam inner, so the foam came out, and I will use the case for something else, like the rest of my camera gear. The teardown is scheduled for when I get down to it, still have some stuff ahead of it.

author: retrolefty
author_rank: Super Contributor
timestamp: August 03, 2016, 07:48:35 pm
content: Quote from: dr.diesel on August 03, 2016, 12:23:08 pmUsually bladder capacity decreases with age, so your Dad is quite the specimen.

author: Kilrah
author_rank: Unknown
timestamp: August 03, 2016, 08:49:24 pm
content: What's most interesting to see IMO is the TV tuner, which suggests that at this time they were apparently actually hoping to sell some to your regular consumer. Later models (Sony has had portable players/recorders for pretty much every media they marketed to pros up to SxS) dropped that and were really only meant for pro use e.g. so the director could play back a recording on the spot to validate it while the camera was shooting the next scene.Another use of these things was as the Camera port suggests to act as a recoder for "miniature" cameras. No action cams back then, but you could have miniature "camera heads" that only housed the sensor/optics and some varying amount of processing, while the recording was done on the deck further away down a cable that was typically either of fixed length or ridiculously expensive. There's one in the attached pic (top left corner behind the screen), this relatively recent one just supplied straight composite and thus thankfully worked over great lengths, but the recorder's left side had a cover that you could remove with a mount and a bunch of contacts underneath so you could latch in the processing unit for presumably earlier cameras that couldn't quite miniaturize the processing down to composite generation in a "reasonable" head size. Obviously it's a battery hog too.Had this unit on my bench back in 2009 for repair because the flat flex going to the Firewire port was torn due to the mechanial restraints going loose and the port wiggling, the owners were using the same unit to transfer video to the computer for editing as for recording so they were slightly in trouble. It has recorded some very unique and memorable aviation footage back when nearly nobody saw the interest in it.The fix was too crude to dare posting given current knowledge, but it worked...

author: SNGLinks
author_rank: Regular Contributor
timestamp: August 04, 2016, 07:20:56 am
content: Quote from: R_Gtx on August 03, 2016, 02:20:53 pmI've got one, along with about 10 other Nagra models. I used to be a Nagra service engineer from '69 to '75 so never got to work on the VPR5.

author: strangersound
author_rank: Regular Contributor
timestamp: August 04, 2016, 02:25:19 pm
content: As Dave noted repeatedly, an amazing amount of engineering in there and getting it all in that form factor. The only sad part being that those names mentioned, Sony, Sharp, and Mitsubishi hardly stand for the level of quality they used to. Not that they're the only ones. You really can't go by brand names anymore, you really have to do a lot of research to try and get a quality product these days. Thank goodness for forums like this and all the other resources available online, and the people that do the serious legwork to determine the origin of products and do real quality testing. Electronics, tools, appliances, you name it...somebody out here in cyberspace is taking the time and effort to help consumers make better choices.AvE pointed out a major issue in all this in one of his recent videos. When people make uneducated buying choices, especially based on price, what they are doing is forcing quality products off the shelves. Lowes is a good example of a big box that used to have a selection of tools that spanned the range from el-cheapo to good quality. But over time, all the quality tools have been phased out in favor of el-cheapo products that sell the most and provide the most profit for Lowes. And it's easy to blame the big box stores, but the responsibility resides with the consumer. As long as people provide a market for el-cheapo crap, that's what will dominate the marketplace.The average homeowner just goes into a big box store, finds what they need at the cheapest price, and goes their way. And then they likely turn around and complain about jobs being shipped overseas, not realizing that it's their purchasing choices that drive this. I personally spend hours researching a product before I ever make a purchase, but I think most people are typically in a hurry and have little time to or money to spare and so the cycle continues.

author: nctnico
author_rank: Super Contributor
timestamp: August 04, 2016, 04:23:29 pm
content: Quote from: strangersound on August 04, 2016, 02:25:19 pmI agree. I don't research everything for hours but on big ticket items I do my homework and sometimes I end up with surprising choices (my current car for example).

author: Kilrah
author_rank: Unknown
timestamp: August 04, 2016, 05:26:14 pm
content: Quote from: strangersound on August 04, 2016, 02:25:19 pmI have and have had a ton of Sony gear and I really can't complain, to me it's at the level it's always been (i.e. right there at the top).Quote from: strangersound on August 04, 2016, 02:25:19 pmAgreed.Quote from: strangersound on August 04, 2016, 02:25:19 pmNo, to me the responsibility is mostly on the store because as you say the consumer is oblivious to all that. They get the cheap tool becasue there is a cheap tool for them to purchase... the store is the one who has the choice of not selling cheap crap and protecting the better stuff. It is of course tough because there's always another seller who will go for a quick buck and undercut any effort, that's why we're where we are now.

author: strangersound
author_rank: Regular Contributor
timestamp: August 04, 2016, 09:07:37 pm
content: Quote from: Kilrah on August 04, 2016, 05:26:14 pmMy last Sony purchase was a dud, but I would still likely choose Sony over others. I've always been a Sony fan and usually you get your bang for buck. The dud was a Sony Bloggie and it crashed all the time from the minute I got it, so I took it back. It was a short lived product, so it might not be a reflection of Sony overall. All companies have the occasional product that fails miserably. I really liked it, it was a very nice alternative to the Flip and related products at the time, but it should have been called the "Buggie".As for the last response, I agree the store also has a role. But the consumer can still play the strong role in the process. If people refuse to buy cheap crap, stores will stop stocking it. You noted the consumer is "oblivious"as an excuse of their actions, but ignorance is no excuse.

author: Kilrah
author_rank: Unknown
timestamp: August 05, 2016, 12:57:06 pm
content: Heh, I've toyed with Webbies back in the days and yeah they weren't of the level we're used to from Sony, and it seems they indeed understood quite quickly that this wasn't a market for them, but they worked. Mine have never stayed long in once piece, but they were good candidates to hack for special purposes.Still have a dusty relic here...

author: Bud
author_rank: Super Contributor
timestamp: August 06, 2016, 05:47:11 am
content: Quote from: German_EE on August 03, 2016, 07:56:12 amThey also separated audio subcarrier from video.