A new project for springtime A Pair of Ampex VR-1200 Quadreplex VTR's - Page 1
Forum section: electronics / projects

author: oldtvguymatt
author_rank: Contributor
timestamp: March 13, 2018, 04:55:18 pm
content: Well springtime is almost upon us here in in Northeastern Ohio and Northwestern Pennsylvania.Time to get a new project started in earnest, late last summer I was able to acquire a pair of 1967 Ampex VR-1200 Quadruplex videotape recorders. After retrieving them from very upstate New York, I was able to assess that they where in good physical condition and had been treated well, but as with anything as large and complex as these machines are they would need a full restoration.To that end I spent the summer acquiring parts, and pieces, along with assembling a very basic compressed air system to use for testing purposes. I also went to work on rewiring all of the removable power cords and fans in one of the machines. I also mounted a color video monitor and did quick testing of the Tektronix waveform monitor. The way the restoration will go is one machine will be restored as close to its 1967 original configuration as possible (it was set up for color recording and monochrome playback). The other machine will be restored and upgraded/enhanced to make it usable as a videotape recovery machine additions such as dropout compensator and possibly a digital time base corrector will be made.Now it is time to really get started on bringing the machine back up. I am lucky to have a complete manual set for the machine as well as extender cards and spare video heads and known good videotape to use for testing.The first order of business will be rewiring the monitor bridge and mounting a newer Waveform/Vectorscope combo in place of the 1967 Tektronix original, also properly mounting the Tektronix Trinitron video monitor on a pull out slide. Once that is completed then the testing and repairing of each individual video processing module will commence (each rack mount module has it's own power supply and can operate independently).After the self powered video modules are in order, then time to work on the constant current power supplies for the video head servo electronics and the modulator/demodulator subsystem. Then those subsystems will be tested/repaired.The final step will be to work on the compressed air and vacuum systems inside the machine, replacing lines and parts as necessary, as well as doing a rebuild on the GAST vacuum pump.I will be posting updates here and on my YouTube channel as things progress, so keep tuned!MattKD8AMGhttps://www.youtube.com/user/mspysu79

author: jmelson
author_rank: Super Contributor
timestamp: March 13, 2018, 07:41:39 pm
content: OHHHhhh MY! This is a level of insanity that brings me to my knees! Geez, do you know the condition of the heads? These are a consumable part, and I'm pretty sure there is no outfit left alive that can do the overhaul on them. (I don't know if they deteriorate over time.)GOOD LUCK with your project!Jon

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 13, 2018, 11:37:06 pm
content: I notice there's two. I can make room in my parent's house.

author: oldtvguymatt
author_rank: Contributor
timestamp: March 14, 2018, 01:59:58 am
content: Jon,The condition of the video heads installed on the machines appears to be good, according to notes written on them, there is less the 250 hours on the set installed on the color capable machine. But I also have several other sets that are refurbished and unused, some 10 mil for 15 IPS recordings and a couple of 5 mil heads for 7.5 IPS recordings.

author: BradC
author_rank: Super Contributor
timestamp: March 14, 2018, 02:46:49 am
content: Beautiful. We had a pair of those in our school studio back in the 80's. They required fairly constant love and attention to keep in top nick and I have very fond memories in being a tiny part of that. Still love the smell of a freshly opened tape reel.

author: floobydust
author_rank: Super Contributor
timestamp: March 14, 2018, 03:45:46 am
content: I worked on Ampex MM1200's no videoand my biggest mistake was I ended up cracking some of the tuned inductors doing calibration.I did have a set of color TV alignment tools but they did not fit well or the slug's were corroded in place as I recall.Just letting you know, to be extra careful.

author: flynwill
author_rank: Regular Contributor
timestamp: March 14, 2018, 04:04:30 am
content: Well that should keep you busy for a while. Best of luck!So it sounds like there are still folks out there with closets full of tape they want to get transferred before it's too late.

author: oldtvguymatt
author_rank: Contributor
timestamp: March 14, 2018, 12:01:48 pm
content: The MM-1200 was a different beast, about 10 years newer then the VR-1200, the audio equivalent of the VR-1200 was the MM-1000 2" 16 track, it used the same frame, deck plate, reel and capstan motors, as well as reel servo control systems. 8 channels of electronics form the AG-440 sat above the transport where the monitor bridge would be and the other 8 channels, power supplies and servos sat in the lower portion where the video electronics would be.But yes advice taken, no tweaking without the manuals and proper test equipment setup

author: oldtvguymatt
author_rank: Contributor
timestamp: March 14, 2018, 03:40:39 pm
content: For those who have never seen 2" Quadruplex videotape, I have attached a diagram from the manual on what is recorded on the tape, plus pictures of a generic reel of the tape with a MiniDV cassette sitting on top the reel.

author: cvanc
author_rank: Frequent Contributor
timestamp: March 14, 2018, 03:52:21 pm
content: Oh wow, this takes me back.I have a background in (among other things) broadcast television. Back in the day there were 2 primary vendors for 2" videotape machines - Ampex and RCA. Different markets seemed to choose one brand over another; I always wondered if this was a sign of nothing more than one company had a more persuasive salesperson than the other did?Anyway I saw few Ampex's but I kept a bunch of RCAs running for years. I actually attended the very last TR-600 school that RCA offered before they shut the school down completely in the early 80's.Best wishes on your restoration project!

author: Keicar
author_rank: Regular Contributor
timestamp: March 15, 2018, 03:04:50 am
content: Awesome project Matt - I have subscribed to your YouTube channel.Karl.

author: tecman
author_rank: Frequent Contributor
timestamp: March 15, 2018, 06:23:58 pm
content: When I was young I always yearned to have a quad recorder. However I knew that even if I had the opportunity to get one, the sheer size and infrastructure requirements would always be a roadblock. I studied the workings and schematics and was always impressed with the complexity, precision and performance of them. RCA and Ampex were the big guys for them. Both firms basically dead today.paul

author: SL4P
author_rank: Super Contributor
timestamp: March 17, 2018, 07:58:58 am
content: I spent the best part of 10 years operating, working on, keeping alive an upgraded VR1200 and 2x VR2000’s - and that was quite an experience - a lot of fun.We also had a VR-3000, HS-100 disc and AVR2’s - moving on later to 1-inch and D2/D1 and BetsSP and DigiBeta.A lot of fun - good luck.We also had RCA-TR60!s / TR-70’s and allSorts of oddball stuff.I loved that sound of the headeheel spinning up - still do!

author: oldtvguymatt
author_rank: Contributor
timestamp: March 19, 2018, 02:38:34 am
content: Part one of the restoration series is on YouTube now:https://youtu.be/Mz3Fx0yUkfM

author: oldtvguymatt
author_rank: Contributor
timestamp: April 02, 2018, 02:18:50 pm
content: Did a bit more work on the VTR over the weekend, no new video as of yet, because I left the tape sitting on the work table where the VTR is in Pittsburgh. Started the work on the audio monitor amp and video switching module, with is the bottom right in the monitor bridge below the waveform monitor.Replaced the filter capacitors with new Nichicon axial capacitors, as the old ones where so large it is unpractical to replace them with radials. Also replaced the other axial capacitors with some new Sprague/Vishay axial capacitors, reconnected the internal speaker and replaced the decrepit rubber insulated power cord. The only things left to do with that module is to spray contact cleaner in every switch and pot then work them and then place the unit back in the bridge, reconnect all the coax and multipin connectors.

author: floobydust
author_rank: Super Contributor
timestamp: April 02, 2018, 10:24:20 pm
content: For replacing vintage axial electrolytics, sometimes I take radials, bend one lead over and solder on extra lead length, with teflon spaghetti. Then I use some silicone glue to tack the cap to the PCB. It depends on the budget I guess and if the cap is really hard to find/expensive in axial, some are 10X the price.Maybe post pics of the PC boards, need some vintage Ampex VTR porn here

author: cvanc
author_rank: Frequent Contributor
timestamp: April 03, 2018, 03:27:16 am
content: Quote from: floobydust on April 02, 2018, 10:24:20 pmLOL yeah me too!

author: oldtvguymatt
author_rank: Contributor
timestamp: April 03, 2018, 03:07:08 pm
content: For most of the Axial capacitors, they are common values, that are still relatively easy to find. The only radial capacitors are the large "Computer grade" Mallory ones that, if they are bad, get expensive quick.Next time I am up where the machine is, I will take some pictures of PCB's, maybe of things like the transistor Flip Flop in the servo system, or the electronic variable delay line in the time base corrector subsystems.

author: oldtvguymatt
author_rank: Contributor
timestamp: April 06, 2018, 02:49:22 am
content: Quote from: cvanc on April 03, 2018, 03:27:16 amHere you go, the Video processing amplifier. Front and back of unit, old crusty and new power cables, boards and component closeups.First the front, back and the power cords, and board closeups.

author: oldtvguymatt
author_rank: Contributor
timestamp: April 06, 2018, 02:50:40 am
content: Here are the additional board pictures.