Sanyo VHR-M107 Videocassette Recorder

Awww, last real post was almost 2 weeks ago, but HAVE I GOT SOMETHING FOR YOU TODAY FOLKS. Remember VCRs? Of course you do, its not like they phased out that long ago (what, late 90's, early 00's?) - I mean, most good parents still have VCRs complete with a collection of Disney VHS tapes. Though at least some of them have relented and donated their machines to the local Goodwill. Which is where I found this gem for $2.49. Gotta love it.

This is really a fascinating machine. There's a bunch of great interweb links that explain how it works n' such, and I'd like to take a quick paragraph after the jump to explain briefly how it all goes down with said links embedded within. But feel free to skip that nonsense and jump into the fancy pictures. This is a picture blog first and foremost after all. Enjoy...

Right then, well we all know that without VHS tapes, the Videocassette Recorder would have nothing to do but sit there like the useless piece of plastic most people think of it as already. VHS tapes are really just two spools containing 812 to 1,210 feet (two major capacities were sold) of thin plastic film with a magnetizable coating. This film is pulled out of the cassette once inside the VCR via a remarkable set of gears, cogs, and tensioning heads and made to move across a recording head which reads and writes the analog television signal to and from the tape, an audio head, and an erasing head. A video of all this happening can be seen here. The recording head (according to wikipedia) "creates a fluctuating magnetic field in response to the signal to be recorded, and the magnetic particles on the tape are forced to line up with the field at the head." Which is damn cool. Interestingly, its also mounted on an angle to get more information per linear inch of tape. Which is doubly cool. Depending on the recording mode you set your VCR to the tape will move across these heads at different speeds (up to 25mph) - faster will get more information density and a higher quality image, but will have a shorter recording time.

So there you have it. Hopefully there aren't too many engineers facepalming right now. 

Next up... pictures.

This model seems to be one of the simpler ones - these are all the inputs and buttons on the whole unit.

I do love these stamped warnings/ cool logos you find every so often

A grounding arm that contacts the metal chassis (see scratches on chassis above) for the antenna and RF jacks - which connects the VCR to your TV through a coaxial cable)

With the top removed

With the front removed. These LED lights synced with the little viewing windows indicating power or recording status. What I like is the plastic part holding the LEDs has room for another right in the middle. From what I've heard it is a rather common practice to have relatively universal individual parts inside different models in a product line. In a more expensive model with more features, there might have well been that 5th LED

Also on the front panel are the buttons you hit for fast forward and what have you. Pressing that button causes these arms sticking out to press the 4 buttons on the circuit board we see in the picture below

This is the tray the VHS cassette is loaded into

Detail shot of just a few of the moving parts and arms connected with springs. Each part in this machine seemed to be like this - a marvel in its own right

With the VHS tray removed

Detail shot of a few of the tensioning arms, pads, and gears that are designed to, I assume, keep the tape taught as it is fed through the machine past the various heads

Here's the main attraction: the helical scan recording head. When you hit record on your VCR, this is where the magic happens. You'll notice it is indeed mounted on an angle, as explained earlier. It spun freely and smoothly. The pins you see sticking up at various angles are what help guide the tape itself across the head

Here are the other two heads, though hell if I know which is which: the audio head, and the erasing head. Together with the recording head above, these three parts are what actually manipulate and read the magnetic bits stored on the VHS tape

Brief intermission for this mystery part mounted against the back panel of the unit. What was interesting was that the metal housing wasn't screwed on or pressure fit in any conventional way, but rather soldered directly to the circuit board inside

No worries though, I pried that metal housing right off

Back to the good stuff - we see here the underside of the metal chassis mounted over the circuit board, which has all the sweet moving parts. It reminds me of those tabletop hockey games I used to play at my cousin's house on vacation...

Detail of just some of the gears n' such on the chassis

This is where the motor was mounted which actually powered all the arms and rollers to move

I dare you to not call this amazing. This little doohickey is what the motor spun, influencing the pin sticking up detailed in the shot below. What I assumed happened was according to if you hit fast forward, or remind, or play or whatever, the motor would spin this guy precisely to move the pin below to the right position, which in turn moves all the other arms and rollers to the position they need to be in. That, or I'm completely wrong...

To be perfectly honest, I'm not sure what this guy is, but it's cool as hell. Looks like a scale model of something you'd see on the Large Hadron Collider. I think it has to do with spinning the recording head

Other side of cool part above with the belt that spun it, or it spun

The recording head removed from its mount

Top of the circuit board

Bottom of the circuit board

Every circuit board has to have a few money shots of cool chips and whatnot on it, right?

That took a while, but worth it in my opinion. That two and a half dollar VCR was an engineering marvel. Gets you thinking about all the time and effort put into designing the myriad of machines we use everyday, only to see them become obsolete in a few years time (or at least become reduced to a fraction its former worth). I'm gonna keep my eyes out for one of the mythical "4 head" VCRs out there which I think are promising for more complexity. 

'Till next time...