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Old 5th Dec 2021, 5:26 pm   #1
_Cosmic_
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Default BSR Factory Workers: reaching out..

Hi everyone,
Would anyone happen to know any of the former BSR factory staff involved in the manufacturing of their crystal cartridges. I think that particular factory might have been at the Monarch site in Old Hill Staffs.

I have been taking to pieces several of their cartridges TC8's C1's etc and know how they work now. I'd quite like to have a go making some elements from the salt as of course you can't get them anywhere now.
I'm hoping that there are ex-members of the BSR work-force on our site?

Many many thanks
Cosmic
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Old 5th Dec 2021, 5:47 pm   #2
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Default Re: BSR Factory Workers: reaching out..

That sounds like you're up for a challenge! I admire your courage.

If you just want to get an old record-player going, then of course there are many suppliers of compatible cartridges around. Musonic for one.

The problem with crystal cartridges has always been that they are hygroscopic; i.e. water-seeking, and usually over time disintegrate, as do crystal microphones.
The modern ceramic cartridges are available in various output voltages, should you wish to pursue the easier route!

Good luck with the project,
David.
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Old 5th Dec 2021, 8:08 pm   #3
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Default Re: BSR Factory Workers: reaching out..

Interesting project, I wish you well. I have taken apart several cartridges over the years, and apart from the crystal element you will need the supporting yoke etc which you obviously know about.
Good luck and let us know how you get on.
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Old 6th Dec 2021, 12:43 am   #4
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Default Re: BSR Factory Workers: reaching out..

Yes, I have several TC8's I bought as a job lot when trying to buy a mounting bracket for a new Sonotone T-20 2 version I bought from the well known dealer in America. (I know, along with most others I didn't realise there was a type 2 either! They didn't send the bracket. The cart doesn't fit my broken T-20 Type 1 as the spindle diameter is very slightly different.

I know how to make the crystal solution but I need to know how they used to make the crystals grow into the small rectangular elements. Or how they cut them down to size.
The newer carts don't output as much voltage as the crystals used to send out to the one valve amps (+rectifier valve) and more importantly they don't fit the deep BSR UA-14 head-shell like the TC8 brackets do. That's why I am reduced to trying to rebuild my carts. Also if i can pull it off, renovate everyone else's that are just lying around useless. Anyway, I would far rather rise to the challenge and renovate things instead of throwing all the history away in the bin forever. It MUST be possible somehow....
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Old 6th Dec 2021, 12:49 am   #5
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Default Re: BSR Factory Workers: reaching out..

I have managed to rebuild a working BSR C1 from 2 broken ones today. These are fairly straight forward if you have time to experiment. The ceramic elements are quite sturdy so you can dismantle everything and rebuild if you have a steady hand and the tools. I just need a bracket for that now so I can try it out on a disc and not just testing with the voltmeter.
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Old 8th Dec 2021, 8:54 pm   #6
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Default Re: BSR Factory Workers: reaching out..

Thanks for all your interest.

I'm still hoping that one of our members who used to work for BSR and knows a little about how their crystal elements were manufactured would kindly get in touch. I know it's a big ask in 2021 but the longer we leave it...

I have ordered the chemicals to make the crystals. I'm wondering what they used to cut the crystals in the right orientation and to the right size.

And also how to monitor the purity of the solution without scientific equipment..

Thanks, Cosmic.
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Old 11th Dec 2021, 3:57 pm   #7
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Default Re: BSR Factory Workers: reaching out..

Has anyone attempted to use the crystal from a piezo gas lighter? It should have a high output. John.
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Old 11th Dec 2021, 6:18 pm   #8
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Default Re: BSR Factory Workers: reaching out..

I agree that piezo ceramic elements can be very robust. I was successful a while ago in rebuilding an HMV 'Double-C' turnover cartridge. These are notorious for broken foil connections to the element, which has metallic plated ends. It was something of a surprise to have success soldering fine wire connections directly to the plated ends of the ceramic material - much more reliable than the previous foil connections retained by the pressure of rubber clamps.

The suggestion of a ceramic element from a piezo gas lighter is interesting. It may well be practicable to grind it down to a size that fits the cartridge.

As for growing Rochelle salt crystals, that sounds like the sort of project that could occupy the next year or so! I recall school chemistry competitions where we grew rather attractive crystals of compounds such as copper sulphate and chrome alum by starting with a small 'seed' crystal on a length of cotton suspended in a saturated solution that was gradually allowed to evaporate. The crystal slowly grew as the evaporating solution deposited more solid on the seed. Rochelle salt might work similarly, but of course it's hygroscopic which presents an additional challenge.......

Ceramic is probably easier.

Martin
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Old 12th Dec 2021, 8:49 am   #9
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Default Re: BSR Factory Workers: reaching out..

Lots of hits on Google Scholar - https://scholar.google.com/scholar?h...crystals&btnG= the first hit being a 1931 paper entitled "The Use of Rochelle Salt Crystals for Electrical Reproducers and Microphones"

This one looks interesting "Influence of magnetic field on growth rate dispersion of small Rochelle salt crystals" from the Journal of Crystal Growth... Journal of Crystal Growth, who knew? There's probably a Journal of Cat Hair Mastication : )

Andy.
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Old 12th Dec 2021, 11:23 am   #10
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Default Re: BSR Factory Workers: reaching out..

I have sometimes wondered if it's possible to do the same thing.
However, when I weighed up the aggro involved against the actual usefulness of the finished item, it didn't add up. Even when working, those carts had low compliance and you'd be limited to mono records from the 50s and 60s. Being unable to play the last 50 or so years' worth of music is a major drawback.

I seem to recall reading on a US forum how someone restored old carts by making new elements (piezo IIRC) but the tone was very harsh. Also how someone else restored those old Philips AG 3012 crystal heads, will try and find the link. Whatever, it seems like it can be done!

Personally, I'd look at making or restoring high output ceramics like the BSR X5H, which have a vastly greater usefulness.
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Old 12th Dec 2021, 11:55 am   #11
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Default Re: BSR Factory Workers: reaching out..

Quote:
Originally Posted by Diabolical Artificer View Post
Lots of hits on Google Scholar - https://scholar.google.com/scholar?h...crystals&btnG= the first hit being a 1931 paper entitled "The Use of Rochelle Salt Crystals for Electrical Reproducers and Microphones"
A link to that paper (from page 2020 going): https://worldradiohistory.com/Archiv...RE-1931-11.pdf
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Old 12th Dec 2021, 6:47 pm   #12
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Default Re: BSR Factory Workers: reaching out..

Somebody here sugeested using these: https://uk.rs-online.com/web/p/vibra...ensors/0285784
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Old 12th Dec 2021, 8:33 pm   #13
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Default Re: BSR Factory Workers: reaching out..

Wow, Nick, they look really good. And being 'bender bi-morphs' they ought to have reasonable output. They look a bit like the two elements which the yoke clips onto in a BSR cartridge.

Having (in a previous life) spent a lot of time measuring things with piezo-electric accelerometers, and using *very* hi-Z_in 'charge amplifiers' to do so (this being before the more recent trend of incorporating that amplifier in the transducer package itself, along with a chip which knows the device serial number and calibration etc etc) - I wonder what happens when you stick the output of these things into a 60s record player input. I suppose they got it to work originally.
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Old 13th Dec 2021, 12:48 am   #14
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Default Re: BSR Factory Workers: reaching out..

Quote:
Originally Posted by ben View Post
Even when working, those carts had low compliance and you'd be limited to mono records from the 50s and 60s. Being unable to play the last 50 or so years' worth of music is a major drawback.

Personally, I'd look at making or restoring high output ceramics like the BSR X5H, which have a vastly greater usefulness.
Exactly! I couldn't agree more.

It's not that I don't like the old turn-over cartridges, I do, but I understand their limitations - horses for courses...and all that!
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Old 24th Dec 2021, 3:32 pm   #15
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Default Re: BSR Factory Workers: reaching out..

Quote:
Originally Posted by Nickthedentist View Post
Somebody here sugeested using these: https://uk.rs-online.com/web/p/vibra...ensors/0285784
Thanks Nick, Yes they do look like like they would work don't they, especially at 1 meg ohm impedance and with a 10um deflection producing 4 volt output.
I think I will order a pack to see what happens. They look more practical than cutting up a flat disc piezo element and fitting it into position. That idea I think was proven not to produce enough voltage to replace crystal cartridge elements in the youtube videos I have watched.
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Old 24th Dec 2021, 4:37 pm   #16
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Default Re: BSR Factory Workers: reaching out..

Wow, everyone has been busy posting since I have been away growing Rochelle crystals.. Thanks to all and all those who have viewed.

Basically what you do is to dissolve 80g cream of tartare in 100ml distilled water in a water bath at just under b.p. Then add sodium carbonate until its saturated then filter off the impurities.
I've tried this 3 times and produced seed crystals It took literally hours attaching 8 of the larger ones onto nylon line so as to suspend them in a saturated solution. This I did and waited for them to enlarge. Next day they had all dissolved into solution! All my work gone.
I evaporated off some of the solution and put it in the cool to recrystallise. It wouldn't, even in the fridge overnight. Even a few hours in the freezer didn't work. It did however crystallise overnight in the freezer and, at least, it didn't look like water ice.

Suspecting that I hadn't filtered off the potassium sodium tartrate and that it was still present in the solution, I heated it in the water bath and the left the resultant solution to cool. After 2-3 days... Success. A couple of relatively large crystals started to grow. I am now letting them grow slowly. It's been about a week now. I have several large crystals and hundreds of seeds in a separate solution. I have documented everything in a lab book so I can try to reproduce my experiments. I am posting some photos of the crystals so far in case anyone else fancies a go at it.

I could do with a few more lab beakers and flasks and glass petri dishes but am improvising with pyrex cooking measuring jugs and plastic containers. And have you tried buying distilled purified water (not just simply deionised) lately? The cost is prohibitive.

Just in case anyone has read this far, I just thought I would let you know how I was getting on.
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Old 28th Dec 2021, 2:55 am   #17
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Default Re: BSR Factory Workers: reaching out..

For those who are really interested please feel free to watch this fascinating US Government Research achieve documentary film about crystal manufacturing during WW2.
It's called Crystals Go To War. 1942.

https://vimeo.com/292256226

It's quite long but very educational, historically speaking and pretty relevant to this thread. Would be a disaster if this footage ever got lost forever.

Another update of my growing crystal experiments coming up soon.
Cosmic

Last edited by _Cosmic_; 28th Dec 2021 at 2:56 am. Reason: More info added
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Old 28th Dec 2021, 11:43 am   #18
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Default Re: BSR Factory Workers: reaching out..

That was an interesting video, thanks!

Bit like some of the videos from Mullards', where they had to have one room just stretching wire to the miniscule diameters to be used in other processes, we forget how all encompassing the manufacture was, and how many discrete processes were working in sync, and how many different skills were contributing to the final product.

Also interesting that it was in colour? Must have been an early application. Did not look like it was added in recent years.
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Old 28th Dec 2021, 2:02 pm   #19
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Default Re: BSR Factory Workers: reaching out..

What a great video it shows a lot of work for a little price
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Old 28th Dec 2021, 8:31 pm   #20
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Default Re: BSR Factory Workers: reaching out..

Thank you Cosmic I enjoyed the film.
John
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