DVCPRO archival transfer fun

I feel spoiled. I use DV video tape equipment sometimes and none of my stuff ever gives any issues. It just works. My stuff is Sony, Ikegami, and a couple of consumer grade mini dv camcorders. Every camera’s tape works in every other deck, dropouts are minimal and usually happen in the first second or two of rolling so if you preroll for “speed” it’s fine. My Sony DSR-1500A will even read DVCPRO media, though I’ve never tried it. Maybe I should?

Our station used to have a bureau down south in another city. This station had a 3-deck a/b roll editing system using DVCPRO. This was in service until about 2008 when everything was switched to HD when the network bought it and actually spent money on the station, unlike Shitclair which owned it in the past. Anyway, they had over 300 tapes of file footage there which were mostly dubbed on this one deck. The time finally came to get this footage transferred to the current digital archive system in use.

I’d been warned that DVCPRO tended to have alignment and timing drift issues that cause tapes to not interchange freely between equipment unless it’s all been field aligned to work together. So, thus, I tried the deck they were recorded on. First thing I found was a filthy transport, so I cleaned it up and replaced the little roller that cleans the video heads on load/eject. Please note in the picture above that there are two heads on the drum – the small interconnect boards just link the two heads to the rotary transformers.

Failure. The deck had severe picture breakup trying to play anything back.

I talked to one of my more experienced coworkers who told me to stop there and use a better deck. See, this 450 series, these were the cheap seats in the DVCPRO bowl. It didn’t even dawn on me until then that the 2-head deck is just not common! My consumer grade DVCAM stuff tends to have four or even six. I opened up one of the nicer decks and found four – it uses a finer pitch head for playback, making it even compatible with the narrower tracks of consumer DV! Also, uh, my decks are in good condition and not packed with 12+years of dust.

Clearly it’s time to deploy superior firepower, which is to say, the cybergoth falls and the air compressor….

Ok, time to get serious about reviving some old forgotten crap.

I want to appropriate the content of these for vaporwave purposes

These decks were known for having terribly bad capacitors; before the great Capacitor Plague and Samsung’s current habit of putting out lots of home electronics with crap caps, Panasonic put out a lot of gear that needed dozens of crappy smt electrolytics changed….. some on boards like this

Oh ok uh wait uhhhhh no no no no what the no the whole thing is just aaaaaaaaaaaaAAAAAAAAAA

I’m gonna go hide now ok

*possum noises*

Finally… After hours of work I got three decks up and running and they all read the tapes from the other bureau fine! I did wind up having to revise the cabinet using brute force and power tools though because the Evertz Video Passport turns out to double as a nice space heater and almost roasted itself once I started rolling video from the 3/4″ deck through it. It needed lots and lots of ventilation. The DVCPRO decks aren’t much better about that but at least they have forced front to back airflow.

The most perplexing moment of all this was when I had one deck working great then I ejected the tape and looked back inside and found the pinch roller lying in the bottom! What the heck? I just replaced it. I don’t know.

More colorful shitposting

The thing around my hair is not a ferrite core. It’s more like a slap bracelet and it’s awesome. It keeps the tail from just lying on the back of my neck.

The big hoop is an old TV/monitor degaussing coil and the box is what it came in. Don’t confuse this Jif with that other Jif. I don’t think either rhymes with Gif. Also, one of my coworkers gave me that beautiful blue hair dye, it’s from the Manic Panic line and I love it.

Channel condition: partly cloudy
Cute lil’ dvcpro transport in need of a dental cleaning
The Smurfhair roller was pretty filthy

Thankfully I don’t have to really do any major overhaul work on these — we have the tooling in house to do it, including PCs loaded with custom software to perform certain adjustments (yikes!) and these decks don’t even speak plain English to you like my Sony DVCAM stuff does… you have to have The Fine Manual in front of you because everything is just by numbers with no text labels in any of the menus! Hurrrrrrrrrrrrrrrrrrrrrrrrrr

The Silliest Voltmeter Ever…

The year…. something like 2004.

The transmitter…. Harris Broadcast PowerCD, a funky Inductive Output Tube based system with modular architecture supporting multiple cabinets.

The silliness: much. Much, much silliness. So here’s a hilarious one: this board is right at the power input to each cabinet and watches for power supply phase loss and provides voltage metering outputs. Power in this case is 480v 3 phase delta and the metering circuits on this card measure the voltage between A and B, B and C, and C and A. The measurement circuit is uhhhh the CACA type. 😉

This Got Hot. The resistors’ markings bleached out from the heat!

So, here’s what you’re looking at. The three resistors are 15K ohm 3 watt and are wired in series with R27 (a PTC 0.15 amp polyfuse device) and the sensor coil inside that LEM current sensor.

The LEM LV25-P sensor is a Hall effect current sensor with galvanic isolation. It accepts 0-10mA and puts out a sense voltage proportional to the current input.

The resistors are dissipating 3.84 watts total on each phase, well within their rating. However, this rating was not assuming they’d be piled up like this and crammed on a board stuffed in an unventilated space in the cabinet!

The end result of this was that one of the voltage readings constantly jumped around and caused false alarms to fill the alarm log…. while we were trying to diagnose another issue.

Note the power reading at the top– that was the Other Issue. Ow. Signal go down the hoooooooole.

I’m entirely confused as to why such a roundabout approach was taken to this when a set of isolation amplifiers with one side being powered off a voltage divider or even a small transformer on each phase would have worked with less bill of materials cost and less heat, but uh

Have a good laugh at this stupid thing.

And I never could even figure out where that leakage came from

Behold, my poor hacked on Ender-3. I had bought a clone of the Micro Swiss hotend (I believe off Amazon) so I could print PETG and other high temp materials without PFTE tubing damage issues. I’d also had issues back then with getting the PTFE tubing to seal against the nozzle so I figured this setup would be great!

Unfortunately, I bought… the lowest caliber of dumpshit.

In what I thought was just desperately throwing parts at my printing issues, which led to “missing layer” kind of faults everywhere, I bought this titanium heat break from TH3D. It works with all the other stock hotend parts, which I’d saved in a box of bits. Turns out that’s exactly what I needed… So here’s what I replaced.

Strange, unlike the stock setup, that heat break doesn’t go in there very far…
’bout five millimeters
Uh. That looks awfully rough. In fact… I ran filament down by hand and could feel it snagging.
This is how far it actually goes together

I’m not actually sure what kind of metal this was made of to be honest or if it was even advertised as titanium, stainless, —???

All I can say though is I suspect it’s way too thermally conductive. I had to print hotter than I expected on this machine and the PID tuning values were WILDLY different after changing the heat break. Previously, with the same filament, this temp tower was just starting to print acceptably at the lowest floor which is 230C; now the lower floor is string city, which makes a lot more sense for PLA. Oh, and no missed layers either.

May I just take a microsecond here

Hey, it’s me, I want to give you some good frequencies. (The part I’m referring to is the very end, and the bandpass filtered beat you hear in the background is the beat to Eple, which follows it on the album. Eple will sound familiar to anyone who’s ever fired up a fresh install of Mac OS 10.3…)

But all that aside, this is about metrology and frequency standards and things my cat likes to loaf herself on top of because they’re warm.

We’re preparing for the installation of a new GatesAir Maxiva DTV transmitter at work. I was gonna say it’s an ATSC transmitter, but… I’d at least like to hope… it’s ATSC3 ready, whenever that rolls out. Sitting in the space it was going to reside in was a weird old Axcera transmitter that never worked right and was yanked out in pieces to be e-waste’d. Sitting on one of the pallets of refuse left over was the reference oscillator for the exciter, which, interestingly, was just a standalone thing without GPS synchronization. The tub in the middle is an insulated chamber containing an oven controlled crystal oscillator. Basically, this is an oscillator in a thermostatically controlled heated chamber that keeps it stable. It MUST be allowed to warm up to full operating temperature before use, or, well… it just ain’t gonna be in spec!

(insert commentary here on how silly it is that I’ve seen OCXOs in battery powered equipment that has a shorter battery life than the warmup time)

Most modern stuff uses GPS sync because it’s a good inexpensive way of obtaining a stable reference frequency and timecode. The usual arrangement is to have a voltage controlled oscillator that’s PLL locked to a 10khz timing signal output from a GPS receiver head. Aside from a little bit of phase noise possible in the system, it’s always spot on. This is why you’ll see funky little cone shaped GPS receiver antennas all over the place at broadcast facilities.

Here’s the Evertz system we have that takes GPS time and frequency references and generates our facility master clocks, black burst, and trilevel video sync. I’ve never really gotten that good a look at the way it operates but I think the black burst is generated inside the automatic changeover unit which also has some distribution amplifiers in the back as well. One of the outputs is a 10.000.00000 (I’m not sure how many significant figures) reference which can be used by a wide range of equipment. After having an, uh, experience, with one of these changeover units (see link above) I wisely do not even look at it hard while we’re in anything but 4:00 AM Sunday morning backwash programming. A frame of Grass Valley distribution amplifiers near it is used to distribute its black burst, LTC timecode, and 10mhz signals to where they’re needed throughout the facility.

This will come into play later.

The toroidal power transformer has two primary windings which were series wired for operation on 240vac. That’s why it says 240 on the AC terminal block shield. I swapped them to paralleled for 120.

More pictures and calibration process — onward

Read more “May I just take a microsecond here”