Posts tagged: video

Oct 21 2012

So today I abused a 30yo robot

That was fun! He’ll be up on ebay on Sunday afternoon.

Aug 16 2011

Workshop updates, August 15th

Recorded a little bit of video from the workshop last night. Dumped it up to YT. Going to try and do this more often.

Apr 20 2010

Camera diagnostics, part 1

Always knew getting the service manual would be a good move.

Dug out the old JVC GR-S707’s. They’re a pair of SVHS-C semi-professional camcorders I picked up off ebay years back. One worked fine, only needing a new microphone muff. This came with me all the way to the USA to do some filming at a convention, and damn near broke my spine in the process.
The other was acquired a couple of years after that and turned out to be actually broken, as opposed to a little temperamental in high humidity. I set it aside as a parts camera, or something to try and fix later. It now may be “later”.

I still haven’t tested the capture rig, but will be in the next few days. I was actually looking for a lens this evening when I dug out the spares/repair cam. I had a couple of ideas though, and tried them out quickly.

The viewfinder displays a heavily distorted and rolling image when filming or on playback. The spares kit included all the proprietary cables, so I tried hooking it up to the capture card. Same result there, only in colour. Very heavy blue distortion.
Noticed however the viewfinder and AV output share the same connector type. May mean I can fit one or the other with a colour viewfinder from a different camera at some point. I think I have an even more elderly camcorder with a colour tube.
Found a tape to test in camera. Noticeably worse playback than on dedicated playback unit.
So here’s the interesting bit: PLAYBACK on the damaged camera works fine. However recording is badly affected.

A/V board eliminated. Viewfinder eliminated. Playback eliminated.

Now, from the diagrams it APPEARS that the viewfinder connects to the CPU board. Probably since on-screen info can be included on the video and the viewfinder separately, so that’s done there.

Pain the bum is a lot of these block diagrams had sections in green, and they were scanned in black and white for the PDF, so large portions are near-illegible grey smears.

Still, that both outputs from the CPU board are effected, including the portions that should be different for each output, says it’s either the CPU board itself, or the CPU board’s trying to fit the on-screen data to corrupted video. And since I can’t see how the CPU could corrupt the video feed as well, we move further down the line.

The overall wiring block diagram has the CPU connect to the THD (no explanation of abbreviations included for PCBs). Schematic diagrams show this to be motor and sensor control for the optics themselves as well as pass-through for video and character data, to the Video board.
The video board seems to have tonnes of lovely little trim-pots, any of which might have gotten out of whack. Two are named “Sync level” and “1H Delayed sig level”, both of which sound to me like they could be the cause of this odd issue. It does seem to be some sort of timing issue, afterall (and maybe more, if the blue tint isn’t an associated effect).

That said, the grip on the camera has always been.. sticky. As in coated with something. It could be something leaked down inside the camera through the zoom controls and onto the PCBs under it, altering component values.

In any case, opening it up and giving it a clean-out would seem in it’s best interests.

Ah, forgot I also bought an original non-PDF copy of the service manual. PCB diagrams are still in greyscale, but in much more detail. Schematics are detailed in colour. Indications of binder-holes though suggest either isn’t (wholly) original itself, or JVC actually sent out service manuals that were photocopied from an original.

Mind you, nice that it even goes into detailing the functions of the pins of each IC used, including part numbers. If I should ever need to make a new CPU board for one of these, it’s nice to know it’s only cost me $300 in processor chips alone. :P

[20/06/2010: Amalgamating old posts from “Dreamwidth Creative Blog” into to re-purpose DW blog account.]

Mar 29 2010

Well, the Shore 75 rubber is now here, the 60 has been returned. I’ve not yet caught up with the orders though. There’s a rare collective motivation going on in the house right now that’s saying “Yes, let’s actually clear stuff out!”

Over the past few days I’ve filled one of the wheelie-bins all by myself just with stuff from the workshop. And there’s more yet to come!
It’s been a really harsh thing to do though. I’m a packrat, and I do tend to use the things I pick up sooner or later. But it’s best not to dwell on it all. The space is far more important atm.

Ordered some more Bonsai prototyping bits, but the aluminium tube was out of stock in the end, so I’m going to have to go with stainless instead.
You see, the first simplification I’m making to the Mendel layout is to use the frame as the runners by wrapping the studding with push-fit tube. It should also have the benefit of making assembly and adjustment easier, if I cut the pipes to the correct lengths. Just assemble and tighten.

Also stripped down the big bicycle frame someone dumped in the alleyway. The front fork stem is the same diameter as the stem on the unicycle I picked up last year. Will have to do some careful grinding and welding, but fitting the unicycle up as the front wheel should be fine. And the frames pedal cranks look like they’ll swap with the unicycle ones, so I can hopefully get the mechanism I was after working alright.
It should make it all into a nice half-horse and buggy. Eventually.

I’ve got a rough forge assembled, but I still need to line it with refractory. Have fire cement and perlite, but think I need to pick up some dry sand too. Well, and some charcoal.

Got some footage from the digital camera that needs editing. Also haven’t yet tested the capture machine I assembled last week. It’s on my to-do list.

Seeing who’s interested in what types and sizes. Think I can afford to get one atm. No reply from supplier atm. Will call them in the morning and make an order for the large blue UKFur shirts.
Also converted the carrying case that came with the shirts into something more like a portable shop by chopping down an Ikea hanging rail and mounting fixings inside the case. Now I can store the rail inside the case and use the case as the base of it.

Yeah, I’m behind on this. But I am catching up.

[20/06/2010: Amalgamating old posts from “Dreamwidth Creative Blog” into to re-purpose DW blog account.]

Mar 11 2010

Vacuum de-gasser progress/update

Just a little something recorded with the new digital camera. The one that you get the video off via USB.

[20/06/2010: Amalgamating old posts from “Dreamwidth Creative Blog” into to re-purpose DW blog account.]

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