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What Are You Working On Now

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Menahem Yachad
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I just received a BG4002 AC from South Africa, for restoration. It appears to never have been worked on, in excellent all-round condition.

Here is the challenge for those with SHARP eyes. 

It is NOT a standard BG4002 AC, by any means.

This is a very unusual piece, with 2 components which are hardly ever seen in the BG4002/4 or BG6000.

I probably worked on one of these special units as a young apprentice B&O tech, over 40 years ago, but since I started CondorAudio in 1998, I have never seen this specific special version.

Who can identify these special ingredients?


the_o_master
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Menahem Yachad:

Who can identify these special ingredients?

It is a DC version and has a CD4/RIAA pcb?

Vintage Bang & Olufsen

Dillen
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Dillen replied on Thu, Jan 21 2021 11:55 AM

Opto reader on the threaded shaft.
Leads soldered to main board rather than plugged.
Carriage position switches rather than an opto ruler.

Martin

Menahem Yachad
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Martin

I should have excluded you! There's not much which you haven't seen.

No, it's not a DC version - the large AC motor and the big 4 caps are clearly visible.

 

So what's so special about this unit?

It was one of the very first BG4002's ever made, immediately after the BG4000 stopped production. 

There were some components left over from the BG4000 production.

One of the most common leftover BG4000 parts which were transferred to the 4002 production was the 4000 platter, which has the strobe markings underneath for the neon lamp (abolished on the BG4002)..

 

But on this unit, there is also the BG4000's Carriage position switches and associated PCB, instead of the later perspex opto-ruler.

As soon as I noticed that, I automatically looked for bits and pieces of the 4000's red indicator slider.......

And of course, as Martin also identified - the lamp on the threaded shaft whose associated circuit counts the revolutions of the plastic wheel.

So this unit is actually a hybrid BG4000/4002.

 

What over-engineering!

It all disappeared shortly afterwards, on the first full BG4002 production (no more BG4000 leftovers)..

 

I love working on these machines - a real pleasure!

 

berni2907
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berni2907 replied on Thu, Jan 21 2021 5:12 PM

Hi Guys!

I am a bit of an electronics virgin. Am working on a beolab 4000 with a spot of foam related damage......

fkatze
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fkatze replied on Tue, Feb 16 2021 5:03 AM

fkatze:

So this has been a while in the works...a few delays here and there...being stuck in another country, etc etc.

 

But I finally put an order in for a new board and keypad for my beocord 8000 to be printed on a commercial printer using better material than I can do.  Found a place with a more reasonable price, and if the test order works out, I hope I'll be able to offer a plastics kit for the BM2000 for anyone interested.  I should receive the test parts in about a month.

Here's hoping.

Orava
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Orava replied on Fri, Mar 5 2021 7:26 AM

How do you people deal with this kind of scrathes and wear outs? Paint, sanding, acid or something else? Tips?

 blah-blah and photographs as needed

Dillen
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Dillen replied on Fri, Mar 5 2021 2:21 PM

Menahem Yachad:

And of course, as Martin also identified - the lamp on the threaded shaft whose associated circuit counts the revolutions of the plastic wheel.

It doesn't actually count. Its output is sensed and filtered for fast pulses and (in some versions) held up against the carriage position to determine when the needle runs in the lead-out groove.

Martin 

chartz
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chartz replied on Fri, Mar 5 2021 8:11 PM

Orava:

How do you people deal with this kind of scrathes and wear outs? Paint, sanding, acid or something else? Tips?

I use a silver cleaner product called Argentil. No idea if that’s available abroad. Silvo perhaps?

 

Jacques

Dillen
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Dillen replied on Sat, Mar 6 2021 7:15 AM

Magic eraser, perhaps, for the superficial dark marks.
if the scratches are deep, the answer is you don't deal with it, instead replace the damaged parts.

Martin

Orava
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Orava replied on Mon, Mar 8 2021 7:17 AM

Big Smile Yes, you are absolutely right, but in this case I should scrap the whole thing, what I dont like to do. Aim is just a make it usefull.

 blah-blah and photographs as needed

Johan
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Johan replied on Mon, Mar 8 2021 8:15 PM

 

 

Hi, I was working on imprving my BeoLab 8000 frets. I used 'Akustikstoff' and double sided thin polyester HPX 'Ultra Mount tape'. The Akustikstoff fabric for me works much nicer than the 60 denier tights I used before (less stretch) and I am pleased with the result that has a bit more texture. Further the LEDs are a bit better visible. The tape is extremely sticky. I used it on the outside and the inside of the sidesSome photographs below.

Also did my BeoLab 6000s that were a bit easier :-).

Regards, Johan 

mmmoller
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mmmoller replied on Tue, Mar 9 2021 12:23 PM

Hi Johan,

 

Good job! Do you have any experience in cleaning dirt spots on the fabric (BeoLab 6000/8000 speakers) ? I have a pair with white fabric and I want to remove the dirt, but I'm looking for ideas how to do it best.

Living Room: BeoVision 7-55 MKII / BeoLab 7-6 + BeoRemote One +  2x BeoLab 8002 + BeoLab 2 + 2x BeoLab 6002 + BeoSound 9000 MKII + BeoSound Core + BeoCom 2 + BeoLink Gateway + BLC NL/ML
Master Bedroom: BeoVision 11-55 MKIV + BeoRemote One + 2xBeoLab 6000 + 2x BeoLab 4000 + BeoTime + BeoCom 2
Guest Bedroom: BeoVision 6-26 MKIV + BeoRemote One + BeoCom 6000
Home Office: BeoVision 10-32 + BeoRemote One + DVD1 + BeoCord V8000 VHS + BeoSound 8 + BeoSound 1 (CD version) + BeoPlay A1 + BeoCom 2
Sewing Room: BeoVision 10-40 MKII + BeoRemote One
Bathroom: BeoPlay M3 + BeoRemote One

 

Johan
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Johan replied on Tue, Mar 9 2021 5:01 PM

Hi, thanks!

I have no experience with cleaning (white) frets, mine were so bad they needed to be replaced. But I do remember threads like this one https://forum.beoworld.org/forums/p/46169/332869.aspx#332869 where the frets were washed. With these large frets this probably will be probably best done in the bathtub :-).

Good luck! Let us know what you will do. If things go really wrong you can always recloth.

Regards,

Johan

Orava
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Orava replied on Sat, Mar 13 2021 10:51 AM

Well, this is confusing.

While reading this https://forum.beoworld.org/forums/p/46214/332959.aspx#332959

I did dig out one of those mechanisms and do some measuring. Beocenter control feeds 3,7v 38mA under load to motor and that does not change when motor is oiled and cleaned like gear wheels. But when I did feed 4,5v from outside supply to test meanings, it had no problem to play and wind. 

Now confusing part is that after that test it did work with out problems with it's own supply too. Nothing has changed on beocenters power feed.

EDIT: Back to problematic Sad

 blah-blah and photographs as needed

fkatze
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fkatze replied on Sat, Mar 13 2021 12:57 PM

I had a delivery today Smile

 

 

 

Yes, I know they are white - nothing a bit of dye can't fix.  The keypad is still really a prototype as all my home prints break the retaining tabs almost instantly when test fitting, they just don't have the flexure required out of my Ender3.  This seems much more promising.

The tuner board is basically be done, as I have tested fit extensively, albeit printed as two parts and glued together - not a long term proposition, but fine for prototyping.  So this should be 100% fully functional.  If anyone wants one, let me know.

Orava
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Orava replied on Mon, Apr 26 2021 12:59 PM

Possibly bad idea for long term usage but it gives me change to make adjustmenst until I get the real thing.

 blah-blah and photographs as needed

lausvi
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lausvi replied on Sun, May 9 2021 7:00 PM

I just fixed a second LC2 light dimmer with the same problem as before.

Sold as non-working, it was again resistor R3 that had gone open. No visible damage anywhere, and a simple replacement of the resistor (5.6ohm, 10% 0.4W) bought the unit back to life.

This unit had some issues with the contact between the dome and the contacting rubber on the PCB. I used some conductive silver paint on the contact surface on the dome and with some trial and error it now works pretty much Ok.

Orava
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Orava replied on Mon, May 24 2021 9:36 AM

Isn´t that beautifull? And it works like a clockw... like a Beogram. Thankyou to Solderon for perfect pulley.

 

 blah-blah and photographs as needed

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