I was digging around in the… uh… museum… here at work and found a whole box of worn out video head drums. Some of them had a very interesting feature to them— piezoelectric tracking.
The head can be shifted up and down on a piezo bender.
Why is this here, you may ask? Well, here’s the reason—
Normally, when you play a tape in a helical scan transport like this, the video heads trace an arc across the tape as the drum spins. This arc more or less perfectly matches the way the video frames/fields are recorded across the tape *as it moves* at normal operating speed.
Purpose of the fixed heads and other gribbles on this drum will be read out of a dusty old service manual some day when I’m not fighting the migraine from hell.
But what about when you are NOT at normal operating speed? The tracking angle will not be correct, and the picture “tears” as the head runs across the boundaries between fields.
Enter the piezoelectric tracking mechanism. By applying a sawtooth waveform synchronized with the head drum’s rotation, Sony was able to cause the head to perfectly track a video field beyond angle differences caused by different tape speeds. Thus, when you grab the jog/shuttle dial on one of the decks employing this system and start moving around, or settle down on a still frame (don’t do this too long!), the picture remains clear.
The Sony J-1 Betacam/SX compact player I use at my desk doesn’t have this, and the picture tears when you mess with the speed or pause on Betacam SP (analog) tapes. On BetaSeX tapes, as my coworker calls them, the digitized frame data seems to land in a RAM buffer somewhere and you can still frame or slow down. The tape transport speed and drum rotation speed in Betacam SX mode are much different, and the angle error doesn’t cause as much of an impairment.
I recall seeing a high voltage warning on or near the head drum inside these decks. Not just for show. It’s about 200 volts!
A much more thoughtful description of the dynamic tracking system and better view of the heads and benders may be found here:
Today’s— uh, victim— JBL LSR2325P active studio monitor. It’s a nice sounding biamplified monitor with an active crossover system and suspicious “Imagine” brand capacitors. Hmmmmm. 😉
Our music producer came to me with this loudspeaker he uses to play his creations for our news director, among other things, because it was crackling and popping ferociously when the input gain knob was touched. I found the input gain knob loose on the rear panel and guessed I’d also find cracked solder joints. But where?
Input gain control is below the inverted plastic bathtub under that board. So how do you remove this plastic bathtub? Desolder the shitty thermoplastic power switch—- which will melt and eject its metal parts. WTF??!!
You can see the switch on the panel here – it’s a snap in flange mount – the only way to get around doing this would be to cut away the plastic flange and back it out, I guess. The tub it’s in is sealed so this wouldn’t create an air leak. But still— AARGH!!! Also, WHY THERMOPLASTIC? I have a problem with this. See, if the switch starts warming up, the plastic will soften, removing pressure from the contacts, creating more heat. Eventually the fault will only clear when the switch either totally loses contact or the thermoplastic erupts into flames.
Proper electronic assemblies use thermoSETTING resins. Glass reinforced polyesters/epoxies are nice. These are resins that set either when two parts (a resin and a hardener) are mixed, or enough heat+pressure are applied to kick over a curing reaction. This reaction is a one way process and the resulting product WILL NOT MELT and soften. It may eventually be flammable, but most thermosetting resins, especially glass fibre filled ones, have a very good track record of self extinguishing.
Phenolics are very common in solderable connectors. You can always tell when you’re dealing with a phenolic resin because it will not soften and allow the connector to deform with extended heating during soldering. These resins are often colored teal blue/green, or a tan color on Amphenol products. Ever wondered what the name “Amphenol” is about? 😉
I don’t even want to think too hard about what that AC power inlet fixture is made of, all things considered.
The header pins leading to both the boards inside this tub were also graced with total shit-grade soldering and I reworked them. There’s one board below with the three jacks and one board above with the amplitude pad and the HF/LF trim filters. I resoldered the input pot and tightened the nut around it with some Loctite purple on it. In theory, I probably should have used blue, but I can’t find the blue, and red is right out of the question. Whatever works, right? I’ve had just as good luck with things like this using nail polish on them.
That’s the fate that befalls any nail polish I buy that looked GREAT in the store but when I put it upon my claws it turned out all watery looking or otherwise unsatisfying. (“NYC Color”, this means you. Well– some of their shades. Some of their newer ones are actually formulated with, well, color, in them.)
After this– I can’t wait for my assistant here to show up so I can run my fingers through his thermal insulation and hear him make silly happy squeaky meows.
I figured now that I wrote all this up I should copy it here finally.
Believe in what you will, or what you won’t, but there are things that lurk in the airwaves aside from our electromagnetic waves.
There’s a radio tower southwest of Miami in the middle of nowhere. Well, kinda not exactly middle of nowhere as McMansions are encroaching on it and it’s next to a country club, but still. It used to be the broadcast tower for Channel 6 before the digital transition. Due to the fact that there was another 6 in Orlando, they had to stick this one waaaay south of Miami to “protect” from co-channel interference between the two destroying the signals of both.
There was an old engineer there, Richard Van Hook, who absolutely loved his job. He was in charge of maintaining the transmitter at the site and the associated equipment. As he got on in years he was fighting cancer but continued going to work there every day until about a week before he passed away. The next day, after he passed, he went right back to work. The security guard at the site (it used to be manned 24/7/365) saw the door open, heard footsteps down the hall.. but…. there was no physical body there anymore 😉
Shortly afterwards they put another engineer down there to watch the site until the analog was switched off for the DTV conversion which put their transmitter at another site about 40 miles north. He was always a little creeped out by the site but refused to believe there was a ghost there.
I was working for a radio station whose transmitter was there at the time. The tower had been sold from NBC to a total smeghead management company, Richland Tower, who laid off the guard and left the site unmanned and unmaintained. I’d often be down there doing maintenance and hear doors opening and closing and footsteps in the hallway, but there was nobody else there in this little tiny building in the middle of a field miles from anything other than a berry farm.
Richland refused to negotiate on a new lease with the university who owned that radio station so we had to abruptly remove all our equipment… then put it back! The transmitters* didn’t survive the moves out and back so I was left to assemble a good one out of the guts of two dead ones.
It was like 3 in the morning and I was sitting on a paint bucket with transmitter parts everywhere when the door opened to the room I was in and closed again. Across the room from me was a small Crown Broadcast transmitter that was keeping the station alive for the time being, connected to an Optimod 2200 processor to handle audio levels and compression.
The Optimod’s front panel lit up like someone had turned the adjustment knob or pushed a button. I looked over just in time to see the display change from MODE -> OPERATE to MODE -> TEST. A test tone started screeching out of the radio across the room (as it did over the airwaves).
I looked over and said “Stop that!”.
The processor turned back to OPERATE mode, the station went back to normal operations, the door opened and closed again and I heard footsteps down the steel staircase fading into the distance.
I fell on the floor laughing, it was the most hilarious thing I’d seen ALL FREAKING YEAR.
There were another couple of times I went to try to contact spirits in haunted buildings. One was in the Biltmore Hotel in Coral Gables. I was there with some of my friends from the station and we were walking down a stairwell in the tower next to where Al Capone used to have a suite and we all heard a whisper “hello!”. One of my classmates had a portable Minidisc recorder running on him with a funky field mic that looked like a pair of earbuds in reverse. We’d tested it prior to going in but now… it was recording *dead silence*. Testing it afterwards showed the equipment was working perfectly fine. Trolled again, but that’s not ALL we we were gonna get. We found access to the rooftop which was via two staircases and an equipment room and were walking around up there when we all heard, very clearly, a toilet flush.
There was no toilet on the roof. The nearest toilet was two floors below us. The only thing above us was a weird architectural dome full atop a ladder that’s potentially made of solid pigeon shit that also housed the 147.150 Mhz amateur radio repeater…
We all just couldn’t stop laughing at this point.
We later went back there with an Ouija board and the first thing that came out of it was my ham radio callsign KG4CYX. I guess they’d heard me use the repeater at some point in time. We asked the spirits there if they or their friends ever hung out on campus, and someone did reply that they often visited one of the older buildings there.
I had been reading about the “Spiricom” experiments and decided to try replicating that, first off because I’m freaking obsessed with electronics and radio, but also because I’d hoped to actually get a recording like they did out of that project. Instead of using a bunch of discrete tone generators to create the voice band audio frequencies, I just synthesized them in Audacity and played the result on loop. As I was messing with the janky little iPod transmitter and receiver I had up there, I heard a voice from behind me (seemingly out of the solid plaster wall) say “Shut up!”. It caught me by surprise and I tried to play back the recording in Audacity—-
You guessed it, DEAD SILENCE. I mean, the least significant bit of the analog to digital conversion didn’t even change (meaning, there was literally, absolutely, no sound there.)
Ridiculous pranksters, they are.
Say, wouldn’t this make a fairly good Creepypasta? Dunno, since it’s not a work of fiction……..
Boy, the clickbait “news” sites are thick as a brick nowadays. So you see a link, or maybe even clicked it – how can you tell if it’s clickbait garbage or not?
First off, take a look for the story they’re talking about by searching via Google News. Look to see if the same subject comes up in a well established source such as the New York Times, Reuters, Washington Post, etc. Huffington Post kinda doesn’t count that much anymore, sadly.
But second, well, visit the link with uBlock Origin installed and active on your browser and see what happens. Do you get bombarded with prompts asking you to disable ad blocking and/or turn on desktop notifications for that site? Yeeeah—- chances are good you’ve found bullshit clickbait. Well, unless you’ve gone to Forbes, but that’s malware spewing bullshit of a different stench. Actually, I primarily run uBlock to protect against malvertising– I don’t really mind ads so much as long as they don’t block the page content or require interaction to get them out of the way first, but the ad networks have allowed sponsors to abuse the privilege of injecting active content for years. Oh how great were the days when ads could only be a 468×60 pixel jpeg or gif??
Look at the article. Sometimes you can actually, once in a blue moon, find a good reliable source cited in clickbait, then sometimes laugh as it contradicts the clickbait article you found it from. More often than not it’ll just lead you to some cesspool like Alternet though.
And then other times you’ll find something that looks so bloody insane that you think it HAS to be clickbait and then you find it proven true by Reuters, BBC, NPR, PBS, NBC, Fox, CBS, CNN, and official White House press releases, and you lose a good chunk of your faith in humanity…. oh wait, that’s just the last week or so… and the next four years… nevermind
Just a quick look at this after it arrived in the mail today– for under $20 shipped, I’m impressed. 170 white LEDs and a clever power system.
You can use AA cells or any of a long list of camcorder batteries.
Boost converter. When it’s running full bore I measured 13.8vdc across the led array. This from six aa NiMH cells…
The board at foreground is a push button LED battery fuel gauge. One to four lights indicate the voltage. When I crank the light on the NiMH cells, it drops to one or two immediately. This thing will really shine on lithium ion…
A ventilated cover goes over that…
Thermal issues? Not particularly. I ran the light full tilt a while and the board got barely bath water warm.
It includes two color matching filters and one diffuser. Hopefully it’ll get a test drive tonight.
I’m wondering if it will handle being hooked up to a 14.4v pack. Specs on their website say 7.2-12v but the TI switcher chip and caps are rated for enough… I guess there’s just one way to find out! Where’d I put those D-tap plugs?
A little background: I drive a car that was made when Ford and Mazda shared a lot of engineering and manufacturing resources. They both used the same engine, but with different intake systems and controls and stuff. I have the Mazda and the dipstick says FoMoCo on it! In addition, well— nobody but me knows what oil filter it takes. It actually takes a CARTRIDGE type filter. Most of the auto parts stores try to convince me it takes a spin on– it’s not. Anyway, this same cartridge filter is used on the Ford models, and I always got either the Motorcraft OEM filter or the Purolator cartridge for each replacement.
Until last night—-
I went to a Walmart store for some late night grocery shopping fun (with extra bonus pallet jack traffic and floor refinishing fumes) and picked up the Motorcraft filter. I noticed that all the boxes on the shelf looked like they’d been previously handled, and some visibly opened. I picked up the nicest looking one… Then I noticed… the box was rattling as I carried it back to my cart.
Pandora’s box.
This simply has never happened before. I opened the box to see why– what was rattling?!
What?!
The shaking was the plastic cage inside the filter rattling end to end. Curious— I’d never seen one of these where the cage was free to slide back and forth. That seemed like a ludicrously terrible idea, as if it did that with the filter in service in the engine, it’d eventually start wearing through the paper.
Then I noticed it was totally askew.
The whole thing tilted a bit like the Leaning Tower of Pisa. Hey, what’s up with that seam? Normally those are pretty closely bonded.
OR NOT! Not bonded at all! I could totally open the seam up with no real effort.
Now I’d like to point out the color of this filter media. Normally, oil filters are made of a thick paper with resin coated fibers, or sometimes a synthetic nonwoven fabric. In the case of resin coated cellulose fiber paper, a thermosetting resin may be used. This is a material that remains workable and flexible during the assembly of the filter, then kicked into its final set state by the use of heat.
This filter shows signs of very uneven heating, coating, or both. No loose fibers were visible… which was a cut above the fresh hell you are about to see here.
Briefly— if you were to place THIS filter in your engine and run it there is a good chance most of the oil circulation would bypass it. Chances are you’d get away without any engine damage.
What follows are weapons of engine destruction.
Fram.
Fram is a name known widely for low cost, retail channel filter products— the cheap ones you’ll find at your local auto parts store. They were originally built by a division of Allied Signal, who have been bought out by Honeywell.
A wonderful testament to the quality of Fram filters follows. This is from the excellent Oil Filters Revealed page that showed me, years ago, that not all oil filters are created equal.
Russell,
I obtained great satisfaction from reading your oil filter survey.
I worked for two years as the oil-filter production line engineer in
an Allied-Signal FRAM facility and I can confirm every bad thing you
have said about FRAM automotive filters. That’s from the horse’s
mouth, as it were.
I’m also a quality engineer and can confirm that FRAM applies no
quality control whatsoever to any of the characteristics for which we
buy oil filters. I frequently saw filter designs which were barely
capable of meeting J806. Many of FRAM’s designs will block and go to
bypass after trying to filter very little contamination. There were
often leakage paths at the paper end discs when these were not
properly centered on the elements. Some designs had the pleats so
tightly packed against the center tube that they would block off in no
time. I had discovered that the FRAM HP1 that I had been buying for
about $20 Cdn was EXACTLY the same as a PH8 inside – the only
difference being a heavier can – no advantages in flow capacity. The
paper filtration media was of apparently poor quality and the process
of curing the paper resin was very inconsistent – elements would range
from visibly burnt to white. FRAM’s marketers admitted that there was
just about no way the public could ever prove that an oil filter
contributed, or did not prevent, engine damage. The only thing FRAM
tested for was can burst strength. Another problem that they have from
time to time is in threading the filter base – often there are strands
of metal left behind on a poorly formed thread.
I have not used a FRAM filter since I started working there. Their
claims are entirely and completely marketing bullshit.
If people really want to protect their engines, a good air filter is
vital (which excludes FRAM from that list as well) and a combination
of one depth and one full-flow hydraulic filter, together in parallel,
will do the job of filtration to perfection.
Thanks for doing a great job in trying to get the truth out! You can
quote me anytime.
[name omitted to protect submitter]
Nice to see that Fram’s complete and total lack of quality control continues to this day. The nice thing about having a car that takes a cartridge filter — NO SECRETS. In fact, I always inspect the cartridge after removing it and letting it drip dry a few minutes to check for any metal or plastic bits. Try that with a spin-on filter!
First up– the Fram Tough Guard.
Well, nice to know the resin curing issues were not present as there simply appeared to be no resin. None at all. On handling the filter, paper fiber came off on my hands. The uneven pleating is a little weird but not a show stopper (I’ve even seen it on Purolator filters for the first pleat or so right near the seam) and the seam is at least sealed, albeit… questionably so, with a great besplodging of glue.
But we need to have a look inside.
Hey wait WHAT?
First of all, that sealing ring around the edge appears to literally be a heat sealed on piece of kitchen scrubber. It’s got enormous pores and would allow contaminated oil to bypass right through it. Second, do you see the support structure?
No.
There is no support.
Oil flows through the filter from the outside in. Under high RPM operation, it may be presented to the filter media at a pressure of over 100 PSI. In response to this, I suspect this filter would simply cave in. Combine that with the loose fiber issue and this filter may spell death to your engine. A structural failure of the filter would shower paper fibers through the entire engine, where they can clog the fine oil passages to bearings, build up in the variable valve timing system, jam up solenoid valves, and possibly even block the oil pump’s pickup screen. That’s a whole lot of GAME OVER right there.
Well, at least this one only left slight amounts of fiber on my hands, compared to the next model up—
This is supposed to be Fram’s finest. The crem de la…. CRAAAAAAPPPPPPP
A mesh backs this filter media. It looks a little like the mesh that supports the cotton gauze media on my K&N air filter. The K&N, however, never has to deal with this kind of pressure!!
Royal Purple’s oil filter has a similar mesh as part of its media, however, its media is actually
a) bonded together;
b) backed up by a metal tube to hold the oil pressure!
Now let’s look at that media— as it RAINS loose fibers all over my hands.
This is Fram’s fancy schmancy “synthetic” media. I guess it’s supposed to be bound together by a resin, but that resin appears to be… just… not cured. Not at all. This filter sheds like our assistant overnight guard at work.
Dear human, please take your other hand off that shiny rectangle and place it upon me as well. And go buy yourself a Purrrrrrrrrrrrrolator.
A metal channel is crimped over the seam, and kind of…. rudely crushed at one end. Possible weak spot, as if the media ITSELF isn’t.
The filter media.
what fresh hairy hell is this
If the other two filters were merely bad, this one… this one is malevolently awful. This one was shedding little dust bunnies of fiber as I handled it. Touching the surface would raise a layer of fibers. Whatever the method used to form and cure the nonwoven fabric media was, it was not done right– resin not cured, insufficient heat/pressure, who knows. It’s a major ugly quality control issue– oh wait, what quality control?
(Note that the manufacturing has been offshored to China since that statement about the quality control was written.)
So, in the case of the two Fram filters, this “quality” is believable. The Motorcraft one is an odd duck though and I honestly suspect a supplier FAKED IT. Here’s why– all of the boxes on the shelf had wear as if they’d been handled, opened, and repacked at some point in time. I have to wonder– were they boxes from factory rejects or overstock that got restuffed with fakes? Dare I say— could their own service centers be involved, saving the retail boxes from filters they install in customers’ cars and repacking them with bulk packed shit filters? This wouldn’t be the first time I’ve seen a lot of defective crap hit shelves at Walmart – I once got burned on an entire purchase of *SIX* SD cards there that turned out to be genuine yet defective repackaged Sandisk products.
They also had some filters from K&N and Bosch there. The Bosch filters, as I recall, are Champion Labs “Performance” line filters and they looked just fine.
From K&N’s website.
The K&N’s– they were the “Pro Series” being sold at the HP series’ prices. See this image for why the HP series rules. Not only does it have better filter media inside, but you don’t need an oil filter wrench to install and remove it. The “Pro Series” are just the ‘Performance’ model Champion Labs filter with the K&N name stamped on it and a higher price tag. This same filter element is used in ACDelco OEM filters.
In short, do not buy a Fram filter or any oil filter from Walmart unless you really want an excuse to do a full engine teardown and overhaul. And if you want a K&N, spend the few extra bucks on the HP series. You’ll be glad you did. For all practical purposes though, it’s the same as the Mobil 1 filter with an easy installation/removal tool built in.
A module upon which the Unobtanium evaporated as the Magic Smoke was lost.
Unobtainium and Expensivium are very vital, curious, yet annoying elements. They are commonly used in parts for electronic devices, particularly those in the world of broadcast RF transmission.
Although no link between actual physical toxicity to humans or any other animals has been proven with Unobtanium or Expensivium, those involved in occupations where they have to procure and work with Unobtanium and/or Expensivium parts tend to suffer a greater number of headaches.
Facebook does not allow this to be shared, interestingly…
It’s a great article I saw mentioned in Ted Koppel’s “Lights Out” on how the Red Cross mismanaged their emergency response in Hurricane Sandy.
I’ve seen many of these same issues with the Red Cross from working with their Miami chapter; while they do a good job of helping out small groups of people after things like house fires, they only appear prepared to deal with a larger situation and are not given the resources to actually provide mass care.
The head can be shifted up and down on a piezo bender.
