How 2" Quadruplex Videotape (VTR) Machines Worked

[@colourist.]

I was a recording operator in the early 80s using all of these machines and still a colourist today! This is a great video!

[@pswooley]

I used this gear in the late ‘80’s. This is one of the best videos explaining the theory of operation I have ever seen. Good work.

[@GregorPQ]

I am currently getting a Rank Cintel machine to work. Do you happen to know some old engineers who could help?

[@TaufiqMarhaban]

Who ever made these video is a genius, clear and scientific yet understandable

[@lambertax]

Not very scientific using the imperial measurement system ;(

[@simonbone]

@@lambertax Yep, that was an annoying thing in an otherwise great film. Especially since he's Canadian.

[@HughWaters]

I still have a Quad head assembly from one of our old VR2000 machines, and a length of tape with the magnetic tracks made visible with magnetic fluid and protected with varnish. Did it almost 40 years ago and the tracks are still visible.

[@TheLawrenceWade]

That's just absolutely great. It's a great introduction to why videotape was such an achievement, and that the $99 VCR from Wal*Mart is just short of turning water into wine. And what makes it cooler is the VHS head switch artifact at the bottom of the screen. I love KZbin but I miss videotape. :) I got to run production Quads in a TV station. I remember sitting on night shift in Master Control, reading a Stephen King novel, just enjoying the sound of one of the machines running happily as it played that night's programming.

[@coffeehigh420]

the music makes me feel like i'm watching a video from some state park where they show videos in they're local small "theatre" in between the time you are looking around the museum of indian artifacts cased in glass.

[@danalee1000]

coffeehigh420 Lol. I know. It was 1995... :)

[@jaspervanderblint7986]

+Dana Lee How!

[@MaroonCorey]

​@@danalee1000 that flute on loop is killing me

[@manonthedollar]

Used to work in a taperoom at a movie studio. Quadruplex was my absolute favorite to work with.

[@jkmac625]

The Ampex AVR-2. I was trained how to use one of these in 1999 to help with some 2 inch archiving to D-Beta. I'd been using the 1 inch format since the early 90's mainly on the Ampex VPR-2B.

[@TysonNeil]

I did some of that around the same time.

[@UNOwen1]

+Dana Lee; I'm a lifelong (at-heart) techno-geek, and stuff like this always fascinates me. I was very impressed by this, because usually, in similar videos which are explaining a bit of techno-history, they keep the story simple, whereas you dig down to the root, and explain the 'minutæ', so to say. There's nothing inherently 'bad' about this type of documentary, but, it oft-times leaves those of us of us who want to understand these things with just the barest of facts, feeling 'half-full'.

[@xmttrman]

The Ampex AVR-2 that is featured was a real workhorse. The station I was at had two... they were the last quad R-R recorders we used until the 1" 'C' format machines totally replaced them. We did continue to run the Ampex 2" cart machines until replaced by the Sony LMS D-2 system.

[@kingbee1500]

+xmttrman The Ampex carts...you mean the ACR-25 mono/ACR-225 stereo, right?

[@mikecumbo7531]

@@kingbee1500the 225 was a D2 modern design

[@Fazemod]

An excellent instructional video. Nice job! My first introduction to VTR technology was repairing Sony Broadcast Umatic machines, much smaller but the same principles in use of course.

[@MikinessAnalog]

Even in the era of television's birth in the late 20's there were issues with synchronization. Timing between the source (camera) and the mechanical television. It still amazes me the maths involved and the brains it took to figure out a way to record (document) it. I believe some of the first 20 - 30 line broadcasts were actually recorded on record using modified record lathes then transmitted over the air (radio) as unintelligible audio noise were some people connected their radios to their lathes.

[@2packs4sure]

Man, i love that music. I feel like i'm on safari with Marlin Perkins and Jonny Quest. Of course Jim is busy wrestling an Anacona.

[@SnepperStepTV]

Excellent production. I'm working with these machines now

[@static-san]

Absolutely fascinating! First time I'd heard of how they got from a composite video signal to a magnetic recording in Quad! Using a modulation signal was genius. This video also neatly fills in a gap in an Usborne kids book I have from the 1980s which talks all about TV production. There is a page that describes (too briefly) the Quad system including showing the rotating head, but next it describes the helical scan approach that VHS uses. I didn't realize until very recently that it just didn't explain Quad at all well!

[@manusudha4269]

Great video .Best explanation. Thank you .

[@Geebax2]

Unfortunately there is an error in the with relation to Amtec. It is not Ampex Tape Error Corrector, it is Ampex Time Element Compensator.

[@stephenbeecher7545]

I said the same thing to myself while watching this.

[@Odessia-ij5ys]

Technology from video recording tape to video discs great leap ahead

[@glynnetolar4423]

I sure would have like to have seen the next section(s) of this video.

[@tekvax]

and I even know exactly where you shot that video! sadly those machines and that audio board are LONG gone now!

[@ihartmacz]

What an excellent video! Thank you very much

[@jeantetreault132]

Very complex technology!

[@marktubeie07]

Loved this - ah, memories! Gotta love the AVR-2s...

[@crappyatlife]

Great video very engaging

[@robfriedrich2822]

One amazing thing, tape recorders were introduced in the USA about 10 years before the first video recorder.

[@datacreed]

well done - great history on recording heads. :)

[@eddievhfan1984]

So on the scale of analog TV signals, magnetic tape is effectively a high-pass filter up until the record/repro head's gap creates a hard stop in the tape bandwidth?

[@MancaveEffects]

This video should have way more views.... shame on KZbin nowerdays.....

[@kirknelson156]

very interesting and well presented :)

[@Tomsonic41]

The BBC experimented with recording video in a linear format for their 405-line system. In this case, the tape had to pass the heads at 16.7ft per second! It was very short-lived, however.

[@jethro1963]

There is a vid on KZbin called - 1958: Introducing VERA - Britain's First Videotape Recorder

[@javierjimenez798]

I love solid state analog devices

[@bobskie321]

I remember during my childhood years in early 1970s our B&W TV not only has a V-hold but also the H-hold as well. We hardly touch the V-hold but the H-hold needs occasional adjustment. The picture falls on its side and we adjust the H-hold and after few seconds it falls again but on the opposite side and we adjust the H-hold back. I presume they were using quadruplex. In late 1970s we don't touch the H-hold anymore. I presume our local TV stations are already using helical scan.

[@danalee1000]

+bobskie321 That's more a factor of the old analog television standard, than what type of VTR was playing back the material at the station, since all stations' outputs would go through a processing amplifier (proc amp) to stabilize the picture before transmission. TVs back then were prone to falling out of H sync with weaker TV signals, especially. We all had to do what you did - how I remember!

[@webbox100]

This is awesome, Dana.

[@SirKenchalot]

Great video, very interesting. Grea to see some actual math in a vid like this and wow they could make a head of 0.01mm back then?

[@erwintimmerman6466]

Looking at this in 2020... Still very interesting. Funny how the wide tape allowed vertical tracks instead of the oblique tracks used by the later equipment. Also nice to see all the different techniques used split over all the modules. Makes it a lot more understandable.

[@Thermionman]

.very cool and interesting!

[@Eli_Santin]

Thanks for putting this up! Did you use an Amiga for the 3D visuals?

[@Odessia-ij5ys]

Had only the fortune to see u-matic system in use ...... video recording on reel to reel only from vintage film footage

[@TinLeadHammer]

"Cycles per second" in 1995? Hertz has been established in 1935 and adopted by CGPM in 1960. Wikipedia says that "cycles per second" was largely replaced by "Hertz" by the 1970s. Ah, at 2-minute mark I see "Hz" onscreen without explaining that it is the same as cycles per second. The formula that follows equates recording time to tape length, this is just bad math syntax, you would be marked down on your high school test. The same math silliness continues. Then you pronounce "Hertz" without introducing this unit of measure. In your playback level vs. frequency story you did not mention that the level starts to drop after a certain point. "Expressed in dB as we do in audio" - dB is just a power ratio that has no direct relation to audio. Small errors notwithstanding, this was fun to watch.

[@robfriedrich2822]

I thought, they introduced FM for video signals with storing video signal onto optical media.

[@honestguy7764]

yes, laserdiscs were in fm at first, until digital audio was implemented. later, one of the fm channel were used to store modulated dolby digital

[@michaelmcgee8543]

interesting!

[@tekvax01]

what was the bed used?

[@DelilahThePig]

Hi8 was a decent format for projects like this. I never quite liked DV. It always seemed to want to go yellow and throw out color information.

[@johnpower68]

Hi8 was a toy format and not professional

[@stephenbeecher7545]

Tach phase!

[@srfurley]

Is that a AVR2?

[@colourist.]

Yep !

[@marathonchartsradio]

What is this music?

[@ArtStoneUS]

For people with hearing loss, that washes out of the voice audio. I can barely understand what he's saying

[@nztv8589]

Looks interesting but can't hear/understand a word being said!

[@leeshepherd6512]

Fantastic video ruined with that awful repeating music.

[@alijanlondon]

totally ruined by the intrusive and unnecessary music

[@paulwalker6297]

Please lose the annoying and unnecessary muzak !

[@louco36957]

man i really HATE that stupid measurement system (inches, feets etc.). Why don't you use a decent system of units like metric? Use METER for distance, KILOGRAM for mass, CELSIUS for temperature and so on. Think Metric!!!!!!!!!!

[@Tmanaz480]

Louco ... Relax mate. Why don't you pop down to you local pub for a nice 568 ml.

[@emilpater2865]

A "half liter" sounds better mate

[@johnhoward3042]

Metric is the work of the devil!

[@Patrick_AUBRY]

I'm Canadian, I use both depending of the subject 🤣

[@AlexEssex8]

We use both imperial and metric systems in England (although probably imperial a little more…)