G'day all,

I was given a Beocord 1600 about 17 years ago, and being a bit of a "Magpie", I've cherished it, doing all the electronic and mechanical repairs it's needed (dried-out electrolytic caps, cracked tantalums, rotten belts, mice elimination, relubricating, etc), and it now forms a major part of my business - recovering other people's old reel recordings (I also do vinyl, and so on).

But the poor thing's main capstan drive belt finally gave up the ghost a little while ago, and while I've found a replacement belt here in Australia, I seem to be unable to perform what (to me, at least, it seems) should be a very simple and straightforward belt replacement. I've ended up disassembling the whole transport assembly, the head assembly, and I still couldn't see any light at the end of the tunnel - so it's all been reassembled carefully, but not working.

Could anyone help to point me in the right direction to get some help to get the beastie running again? I can't find any reference to service manuals anywhere online, not even from the nice people at B&O (and they tried to be very helpful).

If anyone can assist, I would be most grateful. I noticed a lady's earlier post regarding a Beocord 3300, but I can't seem to find the gentleman's reference anywhere.

Thanks in advance for any ideas,

Kind regards,

PC Pete

I would suggest two ports of call! Martin Olsen (Dillen on site) is a whizz with tape players of various shapes and sizes and may offer some advice. Or try the forum at Beocentral where Tim Jarman is as he has repaired my 1600 in the past. He will probably be rude about it (the earlier models were much better!) but he secretly likes the Reel to Reel decks so I am sure he will offer some tips.

Yes, it's a tricky job.
It has been some time since last I had one of these on the bench but
I do remember that you have to form a loop of the belt and
feed it in under the capstan flywheel through a hole in the chassis
with the aid of a couple of toothpicks, icecream sticks or similar.
I'm sure Tim can explain better.

If you got the belt on but it still does not work, you will have to tell more about the exact symptoms.

They are wonderful machines, maybe not technically better than the older ones but in my opinion certainly nicer looking and still not the worst specs.

Martin

Thanks so much for that information - that's exactly what I'm looking for. I guess the capstan spindle has to be eased out of it's bearing somehow, that's where I was getting confused - I think I'm going from the wrong direction.

The belt is the only thing wrong with the Beast. It plays, records, and works just superbly. The volume and tone sliders are getting a bit noisy, but that's only to be expected, and I'm looking around to find a good quality replacement for them (Alps has some that are an almost exact fit!), but apart from that (and a couple of old age problems not unlike my own :) this deck is just wonderful to use.

I've even rewound the end-of-tape kicker coil so it works with a new-model transistor in the EOT board. This was engineering in its truest sense, IMHO. I almost love it when something goes wrong, because it's such a delight to work on.

I'll try and update shortly with the results of the "heart transplant" drive belt.

Thank you all once again.

Pete

The patient lives! But I'm afraid there's bad news...

First, thank you so much for your help and guidance. I finally figured out how to move the flywheel spindle forward without disassembling the play head assembly. Then, with all four of my arms (there's something terribly familiar about this kind of work in every aspect of electronics, and that's that I only have 50% to 66% of the number of hands needed for any given job) I managed to thread the new belt through the spindle hole from the rear, and... eventually.... got it around the capstan spindle while simultaneously undoing and getting past the little spring-laden thingumabob.

But sadly, now I've found that both belts are too long by about 6mm (at a guess). I actually measured both belts (main drive and play clutch belts) from the original (broken) belts, but although these belts had not worn (i.e. no wow or flutter in playback), they must have been under some tension to begin with, and as they're broken, that's impossible to guess at.

So here's a more specific question, and I understand completely if it's not answerable...

Is there some way that folks like us on the other side of the globe can find the correct belt details, apart from the B&O part numbers? In other words, if someone could find out how long the belts are, (and perhaps what their profile is), then users like me would be (hopefully) able to source the correct type of belts locally.

I'd even be interested in putting together a "belt kit" for any models, so other folks wouldn't be in the same position I'm in.

Of course, if someone knows of any manufacturer who already provides these belts, if you could perhaps forward some details, I'd be happy to make them available.

I'm so sorry to keep asking for more information, but I would very much appreciate any ideas.

By the way, I took some high-res photos of the belt-loading operation, which I'd be happy to make available for general interest. I can even put some highlights and pointers and things in, so they might be useful not only for 1600 owners, but other (similarly-constructed) models as well. But I'm not sure how to do that on this site. If anyone is interested, please do let me know.

Thanks everyone!

Cheers,

Pete

If you do a good description with pictures and send it to me, I will put it on site. I can make most things into pdf files if necessary. The 1600 was a very nice Jensen design but they were more problematic that the earlier range. The ability to stand them up was nice though.

Peter, thank you for the offer. I used to do technical documentation, so I will try to put something together with an eye for different models if possible.

I agree, being able to stand up makes the 1600 great to work with in confined areas. I already have a Behringer mixer, Korg MR1000, Stanton turntable, and many VHS and Beta devices, so I can tuck the 1600 back out of the way, and it's still very usable.

I just like working on any device that's been beautifully and thoughtfully engineered. The swing-out preamp boards and modular design of the 1600 is just such a nice touch. Of course, the main switchpanel (where the mains is switched on and off) is an absolute nightmare to work on with older wiring, but the ideas incorporated in the rest of the unit must have been cutting edge at the time.

Not so much of this kind of quality any more, I must say. Mass-engineered for profit instead of practicality and serviceability, most modern designs are just eye-candy at best, and irritating and wasteful at worst. Sigh. I must be getting old. :(

I'll be in touch with some data for you.

Thank you!

Just a flying update... the belts are on, the photos are taken, and the 1600 lives again! My heartfelt thanks to Peter and Dillen for their suggestions. It took about an hour to get the belt on, and then the clutch needed adjustment and so on, but once it's done, it's quite straightforward to do again. The catch is doing it the first time! I will be in touch with Peter to try and get some guidelines and good quality photos, I just need to add some nice helpful arrows and circles and stuff to the photos first...

Very good of you. With your permission, I will get some of our technical gurus to have a look at what you send me and add anything else they can think of!!

Martin and Tim spring to mind, and probably Frede as well! 

Hello Peter, I too am a Beocord 1600 owner, and yesterday I discovered that I no longer can play tapes.

I actually hadn't turned it on for about half a year and was a bit disappointed to discover that the play mechanism no longer worked. The motors were fine (you can hear it when you switch to 19 cm/s) and forward and rewind work perfectly.

I took it apart this morning and (of course) the drive belts were dead - one broken in one place, the other in two places.

The good news: I have a service manual, which I obtained before leaving Britain 30 years ago, in order to convert the beast(!) to 60Hz. This involved getting a new capstan for the motor and a new pair of drive belts. Maybe someone supplied you with the 60Hz drive belts! The manual tells you exactly what to loosen off to replace the drive belts. (removal was no problem because they were busted).

The bad news: B&O no longer have any of the drive belts left. They look like standard O-rings to me. Can you tell me where you got yours?

Here for the record are the part numbers:  50Hz  2732005, 60Hz 2732020.

If anyone is interested how I made the conversion, I can try to document the details. It seems to me that I only had to replace the driver pulley and the belts, but my memory is getting pretty hazy, and I will have to look more closely at my annotations to the service manual.

Presumably your belts were the 2732005 pair.

Stephen

Vancouver BC

Canada
 

G'day Stephen,

 I hope I'm the Peter you meant... (Maybe I'll change my name to Rumpelstiltskin to avoid difficulties in the future?)

Yes, the belts I tried to obtain were the 2732005 (main capstan drive belt) and 2732014 (play clutch belt - that's my name for it, your manual might be more accurate!).

The O-ring belts should be relatively easily obtainable (read: far more easily obtainable than in a backwater joint like Australia) in Canada or the US. You'll need to measure the total length of the belt, and divide that by pi (3.14), this will give you the "radial size" (or the 'overall diameter') of the belt, which is apparently what most belt suppliers use to identify the belts. Your mileage may vary!

I found that a 128mm diameter 2mm profile belt worked for the capstan fairly well, and a 78mm diameter belt for the play clutch belt works OK, although it needs to be stretched a little. I can't measure any worse wow/flutter using this combination than for the original belts, but again, the side bearing loads due to the stretched belts may be something I don't want to think about right now.

Since the belts are liable to have been stretched, you'll probably need to allow a few mm for that, and unless you're lucky enough to find the perfect rubber compound, you may need to order a slightly smaller diameter belt and stretch it a little. (I'm not sure what that will do to the capstan load bearings'side load, though). I obtained the belts from a small specialist belt dealership in Sydney, Australia. Unfortunately, I can't recommend the supplier, as they only stock square profile belts for small model cassette repairs, and they are unable (actually, unwilling) to obtain round profile belts. That might give you an indication of the flawed success I had.

I found this part of the process (identifying the "size" of the belt) by far the greatest obstacle to finding a belt to work! Something which should be so simple (i.e. the total length -or circumference- of the belt, or the length/2 -folded length- would seem to me to be so much simpler and far more accurate than having to figure out how big a circle the belt made and dividing a tiny measurement by 3.1415926535....!!!) is made so ridiculously complicated. I ended up having to send the belt specialist a photo of the broken belt laid out over a sheet of 10mm graph paper with a ruler for clarity. And then they sent me the wrong belt entirely. (It seems they thought it was 1-inch graph paper...)

I'll hurry up the replacement method photos if that would help, but I suspect your manual will describe and document the process far better than I can!

The manual you have is a rare jewel indeed, if you ever decide to make any photocopies or scans, I would be more than willing to reimburse you for the time and effort (hint, hint :) )

 I hope this is helpful (but I suspect not). But I'm happy to offer any other information if it would help!

PCPete:

G'day Stephen,

 I hope I'm the Peter you meant... (Maybe I'll change my name to Rumpelstiltskin to avoid difficulties in the future?)

Yes, the belts I tried to obtain were the 2732005 (main capstan drive belt) and 2732014 (play clutch belt - that's my name for it, your manual might be more accurate!).

Yes, sorry I realise that there is a Peter and a Pete. Whenever people can't remember my name they always introduce me as Peter too

I hate to disappoint you but the manual simply says "Belt" (or "Riemen" - the manual is bilingual English and German!!!) in both cases.

I actually hadn't thought about the belt underneath. It probably behoves (?) me to check that out before I go rushing off to find O-rings. I rather thought that there were a lot of different kinds of O-ring, some neoprene, some from other materials, some with built in lubricant and on and on... but this was many years ago when I had access to someone who knew about these things (I was at the time trying to replace the belt drive on my Connoisseur turntable - I since switched to a direct drive Technics).

PCPete:

The O-ring belts should be relatively easily obtainable (read: far more easily obtainable than in a backwater joint like Australia) in Canada or the US. You'll need to measure the total length of the belt, and divide that by pi (3.14), this will give you the "radial size" (or the 'overall diameter') of the belt, which is apparently what most belt suppliers use to identify the belts. Your mileage may vary!

I found that a 128mm diameter 2mm profile belt worked for the capstan fairly well, and a 78mm diameter belt for the play clutch belt works OK, although it needs to be stretched a little. I can't measure any worse wow/flutter using this combination than for the original belts, but again, the side bearing loads due to the stretched belts may be something I don't want to think about right now.

Since the belts are liable to have been stretched, you'll probably need to allow a few mm for that, and unless you're lucky enough to find the perfect rubber compound, you may need to order a slightly smaller diameter belt and stretch it a little. (I'm not sure what that will do to the capstan load bearings'side load, though). I obtained the belts from a small specialist belt dealership in Sydney, Australia. Unfortunately, I can't recommend the supplier, as they only stock square profile belts for small model cassette repairs, and they are unable (actually, unwilling) to obtain round profile belts. That might give you an indication of the flawed success I had.

I'm puzzled: did you get square belts (and modify them), or did you get round belts with a lot of arm twisting?

PCPete:

I found this part of the process (identifying the "size" of the belt) by far the greatest obstacle to finding a belt to work! Something which should be so simple (i.e. the total length -or circumference- of the belt, or the length/2 -folded length- would seem to me to be so much simpler and far more accurate than having to figure out how big a circle the belt made and dividing a tiny measurement by 3.1415926535....!!!) is made so ridiculously complicated. I ended up having to send the belt specialist a photo of the broken belt laid out over a sheet of 10mm graph paper with a ruler for clarity. And then they sent me the wrong belt entirely. (It seems they thought it was 1-inch graph paper...)

Heheheheh see here for the story about the Mars lander

 http://www.cnn.com/TECH/space/9909/30/mars.metric.02/

PCPete:

I'll hurry up the replacement method photos if that would help, but I suspect your manual will describe and document the process far better than I can!

Here's a scan of the relevant page. This is a BIG manual. 103 pages.

http://www.microtopia.net/family/music/Page74-DriveBelt.jpg

This likely won't stay there forever.

PCPete:

The manual you have is a rare jewel indeed, if you ever decide to make any photocopies or scans, I would be more than willing to reimburse you for the time and effort (hint, hint :) )

 I hope this is helpful (but I suspect not). But I'm happy to offer any other information if it would help!

It's got lots of good stuff - including some emendations from B&O that I pasted in with sellotape, and some that I wrote by hand (sigh).

Scanning this manual properly will be a big project. I'm willing but currently swamped. I'm mildly surprised that B&O don't have this one in their archives as part of Gold membership.

Very nice to hear back so quickly. Thanks.

Stephen

PS: I have in my hand the unbroken "english" belts if that is any help at all.

Stephen

G'day Stephen,

Sorry about the confusion!

I eventually settled on a 1.4mm square profile belt for the capstan belt, as it was the largest square-profile belt that didn't rub against the various pulley flanges and other mounting points. I couldn't get round-profile belts from that particular supplier for love nor money. I'm still looking, though.

Since you have the drive belt (like me, unfortunately with 2 more ends than is actually required ), just measure the total length of the belt and divide by pi. That will give you the diameter of the whole belt. I calculated 132mm for my 50Hz belt, but the 132mm belt I was sent was way too loose - I ended up using a 128mm diameter belt - it's not as tight as I'd like, but I don't want to over-stress the captsan motor or capstan bearings too much.

By the way, looking at the manual page you so kindly provided, one of the worst and most fiddly damn things about the replacement was getting the little 'E' clips and springs off the guide posts (we used to call 'em "Jesus Clips" in my old life, because they were almost impossible to catch if they flew off, and it would be "Jesus, did anyone see where that clip landed?"

The belt catalogue I used had all the belt sizes ordered by diameter (as opposed to length...grrrr....). The belt I ended up with was listed as 128x1.4x1.4. I assume (HA!)  that each manufacturer uses a similar system of belt sizing. But I live to be proved wrong these days. Sigh.

I understand completely about copying the manual, I really appreciate the image you provided, that's above and beyond the call!

Yeah, I was very much involved with the Mars orbiter (as an observer only), that was just so funny to see happen to someone else. NASA are still trying to live that down. That's what happens when a bureaucracy designs an orbiter, I guess. That wouldn't happen if B&O designed the orbiter. It'd still be sending data in quadraphonic stereo to this day!

I hope that covers your questions, if I've forgotten anything, just yell!

Oops, I misread your belt details.. if the belt is unbroken, either lay it out on a flat surface as round as you can make it, and measure the diameter of the circle, or else squish it flat so it lays parallel to itself, and measure that length, double it, and divide by Pi.

There's got to be a better way to measure this stuff...

Well I started with the 50Hz one and got 124 mm so that sounds within the range for yours. I dunno how accurate I was, maybe B&O will get back to me with proper dimensions. Before starting all this I placed a call to their service centre and the guy was emailing "the oldest employee of B&O" and hopefully we might get an answer as to exactly what we are looking for.

I seem to recall that getting the belt on was pretty tough - ie it was a tight fit.

The 60Hz seems to be about 131mm so I am going to see if there is a 130.

A lot of O-ring technology came from Nasa didn't it? That would be the circle complete if so......

Stephen 

 

http://www.superiorseals.com/

I'm guessing mine is the largest one that has 0.070 diameter, namely -050

Yours is probably a -049, tell me what you think.

 But what I really want to know from B&O is do they use BUNA, Neoprene, or ????

We're looking at 44 cents per ring, it looks to me.....

 Stephen 

 

SHHHHH! Don't mention the "o-" word to NASA! They're very sensitive about... you-know-what (I didn't mention any booster)!

That site you mention is a good resource to find. I never even thought about using a bloody great big O-ring... I'm assuming (!) that the best material will provide the same wear and tear characteristics as the factory original belts. Perhaps one of the nice B&O folks could comment on that?

You're right, doing the conversion from miles to nanometres reveals... hmm, carry the 5.... 049!. I'd be inclined to select a buta- type ring (pending official feedback from Peter or other technical folks), as (from my vaguely-remembered polymer science classes) the buta-type results in longer crosslinks and more resilience (but I could be, and often am, wrong!). If I'm right, then a more flexible elastomer should result in less heat build-up and longer life for the belt.

At $0.49 per shot, it might be worthwhile to order a "set", from 046 on to 050, to see what works best. As long as the belt doesn't slip in normal use (the most friction seems to be required at "full reel" rewind/fast forward) and it doesn't overload the motor bearings, it should be fine. If you do find one works well, I would be strongly inclined to try and order a "set" internationally (I'm really unhappy with the square section belts, and the few o-ring manufacturers I've called today here in Australia only sell in commercial quantities... but I'm still looking for an antipodean retail supplier, and I'll update when I've found one!)

The play clutch belt (the one that goes around the back of the capstan spindle, under the filter capacitor stand) is probably the most stressed of all the belts (at least in my experience), so maybe a "thicker" o-ring might be a better option for that belt, in which case a more accurate diameter will be needed, so the side loading is minimised. Sorry to go on about the side loading, but with the age and state of the bearings, I'm really reluctant to overload them, as finding a belt, hard though it is, is infinitely easier (and cheaper) than finding bearings!

I'd better have it out and look at the 2732014 belt

I don't think it's failed on mine.

But clearly it would be a good idea to know what size it is.

I'm pretty sure I didnt replace that when I migrated here. So yours will be the same. What size is it please? I was only talking about the main drive belt.

Of course, rewind and fast forward work fine because they don't use belts at all. Silly of me not to think about this other belt. 

S

The "back belt" (play spool clutch belt) on mine was 102mm diameter (measured using the old belt), but it must have stretched badly before it broke, because even a 98mm diameter belt was way too loose. I'm sure that the square belt profile didn't help at all, although I tried 4 different belt thicknesses. The square profile belts I could get at that size were very "stiff", and just didn't work at all on the tight capstan spindle.

I think (!) an 043 or 044 ring would be about right, but I suspect the ring's thickness (the diameter of the ring rubber) would have to be at least 2 to 3mm to ensure a good fit and to reduce the chance of the ring riding up the groove walls and causing wow problems. That means that we may be better off looking at a relatively large diameter 240/241 for the rear belt, and maybe a smaller 158 or 159 for the main capstan belt.

I've found an Aussie supplier who uses the same O-ring sizes (hooray! some standardisation at last!) but they're in a remote location (near a mining area), so it may take some doing to get the right information back to me. Due to physical limitations, I'm only able to deal with online suppliers, and since I haven't found a good supplier who will provide individual belts/rings, I haven't had any further success at this time, but as soon as I get some information, I'll try and post details here.

 That way, we've got both sides of the Pacific more or less covered (assuming the o-rings work as hoped!).

I'm actually using 2-cent heavy rubber bands for the clutch drive belt, as they work fine for long enough to recover a full 6-inch reel, and they're easy to change (if totally annoying), and they don't introduce any measurable wow (remember, I'm dealing with absolutely shockingly poor media to start with, so a bit of wow doesn't matter one whit when the alternative is the dustbin. Plus, I can take care of absolutely any wow or other speed variations during the edit stage, which is more difficult to explain than actually do!)

OK (it's now Saturday morning and I am thinking things may need to wait until Monday - or perhaps if I am quite sure of myself I can order online but either way it won't get dealt with till then).

1. I had the bottom off this morning finally

a. Who but B&O would put a schematic of the electronics in an envelope pasted to the bottom, for someone servicing this?

b. There is a brown plate made of a material whose name I don't recall whose function is clearly to suppress electronic noise, glued to the base. Unfortunately it has come UNglued - any ideas on what to use to stick it back on with? It sits next to the large electronic circuit board (the one that's hinged, though I didn't touch it. I have an idea some glues are going to be better than others if we are promoting non-conductivity - I recall a taperecorder I owned from a rival Scandinavian manufacturer (no names) that used to pick up radio stations when you used the mike :)

c. My "clutch belt" is completely intact. It's a much bigger cross-section than the other, as you say. I'd be happy to order 2 (or more) of these if we can only suss out the size. I am less happy about taking it OFF my machine when it's working. Once again, some specs from B&O might help.

I think the thing is to wait and see if I get some hard info about O-rings from Denmark. I'm sure that's what they used, but knowing the quality/material/additives/size will make this go easier, if they can tell us. 

I am sorely tempted to put the "english" belts back on, but I will restrain myself. Better the right tools than mess something else up through being impatient.

Just so you know, I have just started scanning the very large manual for this machine! It will be on site soon!

Peter:

Just so you know, I have just started scanning the very large manual for this machine! It will be on site soon!

I hope my reply doesn't turn up twice: I must have misclicked the first time....

I wonder if you got (as I did) the emendations to the manual eg pages 44,84,96,97 and of course the part numbers for 60Hz operation which I wrote in by hand from somewhere (this was a loooong time ago)?

If not, I would be happy to help. I'm just delighted not to have to scan the whole thing (including oversize coloured diagrams)!!!!

Cheers

 

Don't think mine has that! It is however now on site! I didn't do it in colour - it is in two parts already because of size but I will happily do a colour scan of any page if someone wants it. I am lucky in that I have an A3 scanner!

Hold on a second!

Would we expect the 60Hz capstan to be larger or smaller than the 50Hz capstan? I can't find the dratted old one (it probably got lost years ago though I'm mildly surprised it's not with the manual).

Wouldn't we expect the 60Hz make the motor go faster? In which case we would expect MY capstan to be smaller than yours. In which case I should be fitting even smaller drive belts, and it absolutely costs me nothing to try the 50Hz ones.
 

I need some basic electrical theory help here. I'm not gonna do anything till I hear from Denmark - which I was warned might be a few days.

Unless one of the experts here already has the answer to the question: exactly what are the specs (size,material) of the drive belts?
 

(added 40 mins later)

I just found the 50Hz capstan (and the capacitor too that needed to be changed for conversion). It is, as expected, considerably bigger at the point where the twin belts go. So my measurements don't make sense, unless I mixed up the belts somehow. The pair I have are in quite good nick and I think the next thing is to try and install them. The fact that they are considerably smaller than the ones that busted are suspicious. Maybe I went and got the right Orings a long time ago and never installed them.....

More in the morning