Yep searched the entire machine no counter at all...
2" Tape 16 track help?
- Thread starter iomegaman
- Start date
Help Support GroupDIY Audio Forum:
So a bit more info:
Just got off the phone with Cinemag:
The input "7463" is just a simple 1:5 made in July 1974, he said he wasn't sure why it was such a simple design except to suggest there was very little inductance from the heads.
The output "7433"was a little different bifilar 1:1 using 2/3 "Steel 29M6" and 1/3 Nickel made in February 1975 he said its the same as the current CMOB3 but with different metal.
Inputs made in July 1974, outputs ordered in February 1975
It also has a Sequential Shaft Angle encoder connected to a Honeywell Microswitch DC Control motor that is missing the belt between it and the capstan idlers which are connected and have a flywheel underneath...almost identical to a 3M M79 except there is not a single capstan in the head assembly, it uses dual capstans under the reels, the counter system is belt driven from the capstan idlers...(belt is missing)
Just got off the phone with Cinemag:
The input "7463" is just a simple 1:5 made in July 1974, he said he wasn't sure why it was such a simple design except to suggest there was very little inductance from the heads.
The output "7433"was a little different bifilar 1:1 using 2/3 "Steel 29M6" and 1/3 Nickel made in February 1975 he said its the same as the current CMOB3 but with different metal.
Inputs made in July 1974, outputs ordered in February 1975
It also has a Sequential Shaft Angle encoder connected to a Honeywell Microswitch DC Control motor that is missing the belt between it and the capstan idlers which are connected and have a flywheel underneath...almost identical to a 3M M79 except there is not a single capstan in the head assembly, it uses dual capstans under the reels, the counter system is belt driven from the capstan idlers...(belt is missing)
Brian Roth
Well-known member
I'm confused.....how many motors on the transport?
Bri
Bri
The little Honeywell DC control motor is missing a belt that attaches to the capstan idlers on the tape head assembly...both capstan idlers are connected to a flywheel below that is missing a belt that goes to the Sequential encoder/Microswitch motor
It reminds me of the 3M M79 tape path EXCEPT in the 3M model there is a single capstan roller built into the tape head assembly...this is using two motors and then the capstan tensioners in the tape head assembly send control data to the microswitch DC motor/etc...
It reminds me of the 3M M79 tape path EXCEPT in the 3M model there is a single capstan roller built into the tape head assembly...this is using two motors and then the capstan tensioners in the tape head assembly send control data to the microswitch DC motor/etc...
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Brian Roth
Well-known member
OK....best I can see is that it is semi-conventional with a motor for each reel and one for the capstan. The latter is odd, being mounted sideways. I was making sure it wasn't an oddball like a Stephens which has only two motors driving each reel (no capstan or motor).
Unusual design!
Bri
Unusual design!
Bri
Well I'm not sure thats it...the "sideways" black motor at the back is a Bodine fractional horsepower gear motor...it actually controls what I would call the "tape tensioner" rollers...
It IS like the Stephens in that it uses two motors driving each reel...
Here's some more pics...first pic the "tensioner rollers" they are connected and do not move independently of one another...the two long roller assemblies at back have a rubber roller at front and hard plastic roller at back...they are both free spinning...but their assembly is connected to the reduced gear motor by way of a push/pull shaft/encoders
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I joined the Ampex MM 1200 group on facebook and RTZ Professional Audio has come up with some new boards to control the Ampex machines...if this one follows the electronic topology of those there's a chance I can get it controlled via these newer boards and even the possibility of remote control via Windows 10!
musika
Well-known member
Yeah I tried to track down "audio electrical supply" in the internits, seems like they shifted over to "Audio Concepts by Dave Kelsey Sound"...he was in L.A. but I think by the 80's had relocated to Florida and passed away a few years ago...
Here's some screen grabs of the Aug. 1976 ads from R/E/P
Here's some screen grabs of the Aug. 1976 ads from R/E/P
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thakava
I´m into gear...
A Stumpex?
waltzingbear
Well-known member
still not following the capstan drive arrangement yet.
I got, there is a motor (blue) above the encoder (tach) that has a pulley on top that we assume is missing a belt to drive the two capstan rollers.
What is the belt driving? large or small, large like the 3M machines? How does this driven element transfer to the capstans, rim drive type Ampex 300 or various old turntables?
Is it possible to get a picture of that assembly that makes sense (top plate removed perhaps)
re reading some of it, the gear reduction motor looks to be the pinch roller(s) actuator as you describe it.
How are the two outer rollers hooked up, any wires or just physical?
Cheers
Alan
I got, there is a motor (blue) above the encoder (tach) that has a pulley on top that we assume is missing a belt to drive the two capstan rollers.
What is the belt driving? large or small, large like the 3M machines? How does this driven element transfer to the capstans, rim drive type Ampex 300 or various old turntables?
Is it possible to get a picture of that assembly that makes sense (top plate removed perhaps)
re reading some of it, the gear reduction motor looks to be the pinch roller(s) actuator as you describe it.
How are the two outer rollers hooked up, any wires or just physical?
Cheers
Alan
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My take on it (which should be regarded with a huge grain of salt) is that the blue honeywell Microswitch motor that has the Sequential Shaft encoder attached is belt driven from the two aluminium rollers (that is the belt that is missing) is basically for sending counting information...this would be where a tachometer would normally function...although after opening the front black box the magnetic disc might do that as well...as I gather info the two aluminium rollers right next to the tape heads are belt driven together, the one on the right side has a larger flywheel beneath it that I am assuming connects to a belt (missing) that drives the Sequential encoder...the main 2" large roller at the front has a thin flat metal disc flywheel connected to its shaft...it is most likely driven by the tape and the disc looks to be some sort of magnetic reading system...
I will take the top plate off but it requires removing the main motors to the reel hubs (which I am assuming is the capstan function)
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If you look at that first picture that I have labelled "Flywheel Rt head roller"...the large flywheel in the middle of the pic (sorry for quality) is connected to the right aluminium roller that sits right behind where the tape heads are...it is connected to the left roller by a small round belt...but it lines up for a flat belt to drive the Sequential counter on the far right that is blue...
The black box on the left side with the red wire crimps is dead center front of machine and houses the flywheel magnetic disc in the following pictures (I remove the front plate to get those pictures.)
Although now that I look into it, it DOES have a small light bulb over the housing that the disc spins through, with a hole in the top for light to pass through...so it apparently does have an optic reading system that is directly connected to the main roller.
In the second picture you can see the light bulb and the aluminum block with the slit for the disc an a hole for the light.
The black box on the left side with the red wire crimps is dead center front of machine and houses the flywheel magnetic disc in the following pictures (I remove the front plate to get those pictures.)
Although now that I look into it, it DOES have a small light bulb over the housing that the disc spins through, with a hole in the top for light to pass through...so it apparently does have an optic reading system that is directly connected to the main roller.
In the second picture you can see the light bulb and the aluminum block with the slit for the disc an a hole for the light.
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Which two outer rollers are you considering here? The actual rollers for the tape reels both have a motor under each so tape take up and send are both direct driven...the two tensioner rollers on the round aluminum discs are free spinning and simply spring based tensioners.
The two rollers right behind the heads might be driven by the Honeywell Microswitch DC control motor with the Sequential Encoder via a flat belt to the right hand rollers flywheel...I'm not sure how the honeywell functions...need to look u a data sheet on it. I did find an OEM Sequential encoder same model and make as the one here (on ebay) and immediately purchased it.
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waltzingbear
Well-known member
the rollers I was referring to were the tension rollers, the motors would never be referred to as rollers, they are supply and takeup reels.
so tensioners are purely mechanical (L and R arms)
so tensioners are purely mechanical (L and R arms)
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Correct...they are mechanical spring loaded and activate a switch when fully rotated (which is a little more than 90 degrees)...upon inspecting them the left side switch is missing the metal contacts.
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waltzingbear
Well-known member
that is an optical disc, not magnetic. the red and white wires to to LED and phototransistors on both sides of it.
on a Stephens that disc on the underside of the turnaround idler is where all the speed data comes from for control. Here is could be either speed or simply tape location. don't know yet.
so if I understand correctly, the left capstan is the shaft of the large pulley under the deck that should have the belt to the blue motor. and the right capstan is driven by a small belt on the upper portion of the shaft.
on a Stephens that disc on the underside of the turnaround idler is where all the speed data comes from for control. Here is could be either speed or simply tape location. don't know yet.
so if I understand correctly, the left capstan is the shaft of the large pulley under the deck that should have the belt to the blue motor. and the right capstan is driven by a small belt on the upper portion of the shaft.
