UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Vintage Audio (record players, hi-fi etc) (https://www.vintage-radio.net/forum/forumdisplay.php?f=14)
-   -   BSR UA8 tonearm problem (https://www.vintage-radio.net/forum/showthread.php?t=153630)

Armbored 1st Feb 2019 12:17 am

BSR UA8 tonearm problem
 
Hi all,

Continuing saga of the UA8 for me... I feel things are getting closer to a conclusion now though. I stripped down the autochanger and reassembled after cleaning and greasing where necessary. My issue now is that when the autochanger starts the cycle, the tonearm raises and then sets down in the rest again, without swinging in to set down on the record. The size selector seems to be working okay, the finger gets flicked on the way down. Thanks to members of this forum, I have the manual courtesy of the ad 'up top', which states this to be an issue with the Stop Pin or Stop Bracket assembly bearing. I've checked these and I think the Stop Pin is not falling or coming down when required but I can't think what's stopping it, I have watched the cycle numerous times but nothing is apparent to me. If anyone has had a similar issue, please let me know your thoughts.

Thanks in advance, as always.
Mike

RojDW48 1st Feb 2019 1:57 am

Re: BSR UA8 tonearm problem
 
I have had that issue but it has always been old, gluey grease. I read that you have cleaned it all up.....but try heating up the mechanism with a hair dryer and see if it improves (very un-technical therapy). You might have missed a bit!

leslie5555 1st Feb 2019 6:50 pm

Re: BSR UA8 tonearm problem
 
I think it could be the same problem I had a while ago.
Do a search for BSR UA8 intermittent fault. And read my thread about it.

Michael Maurice 1st Feb 2019 7:15 pm

Re: BSR UA8 tonearm problem
 
this is the thread Leslie is referring to

leslie5555 1st Feb 2019 10:22 pm

Re: BSR UA8 tonearm problem
 
Thanks Michael thats it

Armbored 2nd Feb 2019 10:13 pm

Re: BSR UA8 tonearm problem
 
Thanks all for the feedback, I will research and see what I can find.
Mike

Armbored 5th Feb 2019 10:07 pm

Re: BSR UA8 tonearm problem
 
I've managed to work out what was wrong here. After some trial and error and slowly examining the complete autochanger mechanism, I found I had reassembled it incorrectly. Thankfully I had taken plenty photos before dismantling, so I had a reference. Two pins were not in the right place, preventing them from acting when required. Once corrected, the whole system is working well. Just need to replace the flex now and we're done! Thanks to all for your help, this is a great site!

Armbored 7th Feb 2019 12:44 am

Re: BSR UA8 tonearm problem
 
Ahem, I was a little hasty saying it was 'fixed'. Need to read the thread about intermittent fault... Sometimes it works, invariably it doesn't.

Now, a problem which seems to be worse than before, is really bad hum. I replaced the old flex with a 2-core double insulated cable, 3A fuse and wired it exactly as the original but the hum is worse. It gets louder as you increase the volume. Any suggestions, folks?

When I touch the top plate of the deck, there is also electrical leakage or 'capacititive coupling' as I believe is the correct term. I seem to be particularly sensitive to this while others not so much, does anyone think it's anything to worry about?

Mike

Edward Huggins 7th Feb 2019 11:24 am

Re: BSR UA8 tonearm problem
 
So far we have only covered the BSR UA8 deck, now you are reporting as to it's relationship to the amplifier. Is the UA8 deck plate earthed to the amp?

AC/HL 7th Feb 2019 11:44 am

Re: BSR UA8 tonearm problem
 
Yes, more information required. What player is your UA8 installed in?

Techman 7th Feb 2019 1:03 pm

Re: BSR UA8 tonearm problem
 
Possibly if it's a combined volume/on-off switch unit, then when you rewired the mains lead you may have got the mains lead too close to the signal wiring/connections to the volume control part, particularly as you say it increases with volume control adjustment.

As said, more information is required.

Armbored 7th Feb 2019 11:48 pm

Re: BSR UA8 tonearm problem
 
Sorry guys, agreed!

@ AC/HL; It's a Dansette Major Deluxe.


@Techmnan; Not sure what you mean there, I just de-soldered the pins attached to the old cable and re-soldered the new cable in. Is there any other consideration? Thanks.


@Edward; Not at home at the moment so I can't check but I don't think so.

Edward Huggins 8th Feb 2019 11:38 am

Re: BSR UA8 tonearm problem
 
What are you calling "Pins", do you mean the solder tags on the on/off switch at the rear of the volume control that the mains lead is connected to?
Your Dansette has a main isolated chassis, so you might consider using a 3 core mains cable instead. This should reduce any hum to a minimum if correctly wired - we can advise as to this so as to avoid an "earth loop".

'LIVEWIRE?' 8th Feb 2019 1:07 pm

Re: BSR UA8 tonearm problem
 
One of my current projects is the repair of a Dansette Major (not Major Deluxe, but they are very similar). As the amp. has a mains transformer, a three-core mains lead can be fitted, so that the amplifier chassis can be earthed, as can, if necessary, the front panel, including the metal speaker grille, though, in the case of the Major, this is earthed via the amp.'s fixing screws. Careful routing of the mains and signal leads is still needed to ensure minimum hum, though.

John10b 8th Feb 2019 7:37 pm

Re: BSR UA8 tonearm problem
 
On the Dansette Major Delux that I’m refurbishing the speaker grill is plastic and not metal.
Cheers
John

'LIVEWIRE?' 8th Feb 2019 11:28 pm

Re: BSR UA8 tonearm problem
 
Fair enough, John, but the remainder of my post #14 still applies.

John10b 9th Feb 2019 10:38 am

Re: BSR UA8 tonearm problem
 
Yes Livewire I agree. I’ve just fitted a 3 core mains cable and earthed the chassis and deck, After replacing a number of the usual components the rp is now working fine.
Cheers
John

Armbored 12th Feb 2019 1:35 am

Re: BSR UA8 tonearm problem
 
Hello all,

Thanks for your replies, I responded a couple of nights ago but the message doesn't seem to have come through.

@ Edward; yes the tags are what I mean. I've replaced the 2-core with a double insulated 3-core, wiring in the live and neutral as before. Where would be the best place to connect the earth?

@ Livewire; thanks for the advice re the cable routing, I did not realise this was significant, but have now taken more care with the replacement cable.

Thanks
Mike

'LIVEWIRE?' 12th Feb 2019 9:49 am

Re: BSR UA8 tonearm problem
 
On the Dansette Major I'm in process of repairing, I've replaced the twisted pair of wires used to connect the P.U. to the amp. with a length of screened audio lead, which, IMHO, should reduce the hum level, but I've yet to try it as there are issues with the cartridge wiring to be sorted out first. My feeling is that Dansette only used twisted pairs of wires for this purpose as it was/is cheaper than screened lead, though I may be wrong.

Edward Huggins 12th Feb 2019 11:26 am

Re: BSR UA8 tonearm problem
 
Yes, they used twisted wires as it was cheaper, but usually quite effective. Connect the yellow/green mains earth wire to a good solid point on the metal chassis of the amplifier.


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