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#1
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Ampex ATR100 operating issues
Hi,
quick question. I have an Ampex ATR100 here that when you rewind a full reel, the machine does not brake the supply wheel once the tape runs out. Leaving a full reel at full velocity flapping about for ages. Should it do so? I have read the Service Manual but can't find any reference to what is supposed to happen when the tape runs out. This has been reported as a fault with this machine. I know the reel motors do not have brakes, and their primary function is to keep the correct tension between both reels and the Capstan motor, and can run backwards and forward to achieve this. I would guess running backward as a brake at tape runs out should be a feature. The only braking I can see though, is the Emergency braking employed on loss of power during operation, when the motors spool down by driving a lamp via a relay opening at power loss. I can't find these lamps to check them, where are they? I have carried out the tension arm checks as stipulated in the manual, they all check out fine. What is a bit weird is that with no tape threaded, moving the supply tension arm past midpoint causes the capstan motor to operate forwards. I have no idea whether this is normal or not. I have a feeling there is a problem here, but am struggling to identify it. Cheers, Gareth. |
#2
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Ampex ATR100 operating issues
Gareth Magennis wrote:
I have an Ampex ATR100 here that when you rewind a full reel, the machine does not brake the supply wheel once the tape runs out. Leaving a full reel at full velocity flapping about for ages. Should it do so? If you put your finger on the righthand tape guide and pull it toward you, does it stop? I have read the Service Manual but can't find any reference to what is supposed to happen when the tape runs out. This has been reported as a fault with this machine. When was the tension adjustment last done on this machine? You will need a scope and a tentelometer... you CANNOT do the adjustment with fish gauges like you can with the 440. Go through the whole tension procedure and you will either find that the problem is solved or you will come to a point where you can't get some adjustment to come in at all. This is likely the result of one of the tension servo loops having drifted. The only braking I can see though, is the Emergency braking employed on loss of power during operation, when the motors spool down by driving a lamp via a relay opening at power loss. I can't find these lamps to check them, where are they? They are 211 lamps, I believe they are under the top cover. I have never seen one fail, ever. Your problem is not braking, your problem is a servo slamming full-on. I have carried out the tension arm checks as stipulated in the manual, they all check out fine. Does this include all the servo adjustments or did you just check the arms with the tentelometer? What is a bit weird is that with no tape threaded, moving the supply tension arm past midpoint causes the capstan motor to operate forwards. I have no idea whether this is normal or not. That's how it's supposed to work! You move that, the transport thinks there is too much slack on the supply side, so it moves the capstan forward to equalize tension between both sides. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#3
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Ampex ATR100 operating issues
I have carried out the tension arm checks as stipulated in the manual, they all check out fine. Does this include all the servo adjustments or did you just check the arms with the tentelometer? *********************** This procedure was just to check the tension arm sensors were reading the position of the arms correctly. All done on a 5v go/nogo reading from testpoints 5/6 on the Reel Servo PCB as per manual. I don't have a tentelometer. I might get one, though. Gareth. |
#4
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Ampex ATR100 operating issues
Gareth Magennis wrote:
This procedure was just to check the tension arm sensors were reading the position of the arms correctly. All done on a 5v go/nogo reading from testpoints 5/6 on the Reel Servo PCB as per manual. Okay, the whole transport alignment will take an afternoon, and it will require a scope, a tentelometer, a greenie screwdriver, and the extender card that was shipped with the machine and ought to be in the card cage if nobody has scavenged it. It is a royal, royal pain in the neck. The manual has complete details on the whole procedure. But the machine will be much easier to use afterward. Are you located somewhere where you could have ATR come out and do it? Mike Spitz is gone but he had a couple guys working for him who were okay. Might be best to have someone show you the procedure. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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