SimonSays

To complete the thread, I can confirm that a 70mm (OD) 3mm nitrile o-ring fits the rewind pulley beautifully. you could probably use something smaller (say, 65mm OD) but bigger would be too loose. I would also say that the nitrile is probably too taught to be used as the main pulleys. Thanks for the Mike Harris link, Dela. I doubt I’ll be leaving him unbothered for long

Thanks, Dela. I’m certain that’s it (now it’s been pointed out!)… That rewind o-ring looks to be ~65mm x 3mm from what I can see. It’s fairly easy to source modern nitrile o-rings of that spec so I’ve bought a few around that size to experiment with - as long as it grips the pulley and engages with the drive wheel i should be able to find something suitable. I couldn’t find your recommended Gearspace post but there are a couple of helpful YouTube videos so I’ll get busy and report back. I do have the grey silicon drive belts so the o-ring should see me right.

Any more info on both the Nagra III service manual (i have one in German but not English) and the source (preferably UK/Europe) for a rewind belt? thanks

(Apologies for the shameless click bait title) I've just acquired a 1963 Nagra III B. Long story short, it plays silently from a mechanical noise perspective. Accelerated fwd is also quiet. Rewind, however is making a fair amount of what sounds like spindle play/oscillation noise. Today, having been cleaning and investigating (unit all ways up and down) it started making a more alarming bumping noise on rewind. When I went under the hood I noticed the pulley connected to the right/take-up spindle was bumping on each revolution. I disconnected that spring tensioning it to the motor plate and turned the tachymetric wheel by finger to try and track the bump down. This crumbly brown/white stuff started falling from around the area of the tachymetric wheel... I've done a bit of macro photography with a loupe (pics attached). Any idea what this is? The bits are around 1-2mm down to more-or-less dust for rough scale. My best guess is some sort of (very old) bushing. The teeth marks in bits of it might be the result of it sticking to the outside if the tachymetric wheel. Could the lack of this be the cause of the oscillation noise? I'm hoping it's not something impossible to replace?! Thanks for any assistance.

Hello everyone - I’m also jumping into this thread as a first time Nagra owner I have just purchased a Nagra III (a basic B model from 1963). I’m London, UK based. It looked like a good bet - has the leather case, looked tidy but not too clean in the pics, helpful seller etc. I’ve given it a thorough and careful clean - heads look good, pinch roller seems to have lots of life in it, playback sounds good through the internal speaker, dust cover was moderately yellowed so I’m peroxiding that as I type. Couple of possible issues - the lower tape speeds/EQs function as expected but the 15ips speed seem to be inconsistent… under no tape load it actually slows down from the 7.5ips setting. I heard absolutely no mechanical noise from the internals with normal playback but rewind creates a loud whirring noise. I’ve opened it up and have spotted a bit of what I assume is battery discharge gunk crystallised around the underside of the back left of the unit - easy to clean up but I don’t know what it may have done to anything it contacted. I can see it in the battery compartment but that’s probably been cleaned previously. The unit had a calibration seal (from 1981) that I removed to open it up. The motor has a large Dymo tape code on it - not sure what this might signify? A previous service/repair perhaps? The noise seems to be play somewhere around the top of the motor area causing vibration. It’s noisier with no tape causing loading but not noticeable at normal playback speed. I’ve not been able to test recording (no suitable mic or banana plug cables - Amazon is delivering the latter so I can test line input and output which is how I plan to use it). All thoughts and advice gratefully received!