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Old 28th Apr 2022, 6:23 pm   #1
Mr_H_RetroTech
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Default Dansette Bermuda Refurb

Hi everyone,

My current project is a Dansette Bermuda Mk 1 (1962ish) refurb. I found this thread - https://vintage-radio.net/forum/showthread.php?t=137767 - which is a Dansette Major restore and contains a lot of useful gen. So, I just wanted to post what my refurb plan is and ask for your comments and advice on it.

I've attached the cct dig for reference.

First, the Bermuda works as is but as ever there are certain components that should be replaced. These are:

The multistage electrolytic will be replaced by individual 33uF and 22uF at 400Vdc and 22uF at 25Vdc. (Originals are 32uF and 22uF at 275Vdc and 25uF at 25Vdc). BTW this can does not have any markings to indicate which terminals belong to which cap so I shall have to trace the connection on the PCB. Any tips?

I'm going to replace the 0.05uF and 1800pF caps with modern versions as a matter of course. Any recommendations for suitable replacements? I'll replace the 2 resistors just because I can

I would welcome advice on replacing the metal rectifier - it looks like a Siemans E250 C50 - so, what would be the best way to replace that?

The mains transformer looks in poor shape. Looks like much of the wax around the windings has melted and the waxed paper wrappings are badly distorted. So, I'm thinking it needs replacing. Problem is, so far, I've been unable to identify a suitable modern version. I'm guessing noone wants a 6.3 v secondary these days. Any suggestions?

Other than the above the amp electronics look OK

Another request for advice is about earthing. The amp is chassis ground and isolation is provided by the mains transformer (as per cct dig). However, someone had wired the mains earth from a 3 core mains cable to the common terminal on the tone are terminal block. Would adding some earth bonding between amp chassis, record deck chassis and mains input be a good idea? Added safety and reduced hum, perhaps?

Regarding the deck - a BSR UA 14 Monarch - it is in good shape. It was gummed up, as usual, but I applied my recent experience of bringing back to life a Garrard SP 25 Mk 3 and a Garrard SL95, have degreased and relubed it. The motor runs smoothly and quite quietly. I have sourced a NoS drive wheel so that should help get the platter running at the correct speeds. I have a source for a NoS stereo cart but the output will be a little low for this amp. If that proves to be an issue (output volume too low) I shall introduce a preamp. Sound like a plan?

That's all for now - any suggestions/comments/advice very welcome.

Thank you!

Best

Barry

Last edited by Cobaltblue; 28th Apr 2022 at 7:26 pm. Reason: Rule B8
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Old 28th Apr 2022, 6:34 pm   #2
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Default Re: Dansette Bermuda Refurb

That schematic will get removed.....Forum rule B (8)

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Old 28th Apr 2022, 6:47 pm   #3
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Default Re: Dansette Bermuda Refurb

Apologies. I thought because I had purchased the schematic legitimately I could use it in a post. 🙁
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Old 28th Apr 2022, 7:15 pm   #4
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Default Re: Dansette Bermuda Refurb

If you would like to send me the capacitor, please pm me first, I can restuff it for you, the contact spacing will line up with the current layout for ease of replacement and to keep it original looking.
If you bring a three core 3Amp mains cable into the chassis, live and neutral are as the old was but the earth connects directly to the chassis with a crimped eyelet, nut and bolt.

Nice little record players.
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Old 28th Apr 2022, 7:16 pm   #5
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Default Re: Dansette Bermuda Refurb

Yu will have great diificut t in fin a suiablester cartridges for the amplifier - the ideal one being a BSR X5H. You will need to use a simple Op-Amp (Pre-Amp) and take its power sut source from the EL84's cathede c.25V. Be careful you do not create an Earth Loop by connecting the amp chassis, motor plate and mains earth all together. The ideal cartrdhes is BSR T
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Old 28th Apr 2022, 7:34 pm   #6
Lucien Nunes
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Default Re: Dansette Bermuda Refurb

Quote:
Looks like much of the wax around the windings has melted and the waxed paper wrappings are badly distorted.
This is not uncommon and I would not condemn a transformer just for looking a bit shabby. It might be generally sound internally where it matters; if it is not running excessively hot (indicative of shorted turns) I would retain it.

Quote:
I would welcome advice on replacing the metal rectifier
A UF4007 diode or any similar, plus a series resistor to replicate the forward resistance of the selenium rec. Others might have top-of-head experience of the ideal value. Many would disagree but if a selenium works OK (some do not, the resistance goes up with age) I tend to leave them in circuit.

Quote:
replace the 0.05uF and 1800pF caps with modern versions
If the 1800pF is a ceramic type it is unlikely to need replacing.

Quote:
Would adding some earth bonding between amp chassis, record deck chassis
With a fully isolated circuit it is arguably a very good idea. However, if one wants to be pedantic, one would note that modifying the safety arrangements away from the original manufacturer's design, puts the onus on the modifier to demonstrate suitability and compliance. When maintaining the original configuration, that onus is on the (defunct) manufacturer.
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Old 29th Apr 2022, 10:55 am   #7
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by Edward Huggins View Post
Yu will have great diificut t in fin a suiablester cartridges for the amplifier - the ideal one being a BSR X5H. You will need to use a simple Op-Amp (Pre-Amp) and take its power sut source from the EL84's cathede c.25V. Be careful you do not create an Earth Loop by connecting the amp chassis, motor plate and mains earth all together. The ideal cartrdhes is BSR T
Thanks for that. You are correct but I found a couple of Dansette refurb specialists on line who offer packages of stereo cartridges and preamp. So, I might try them.
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Old 29th Apr 2022, 11:04 am   #8
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by Lucien Nunes View Post
Quote:
Looks like much of the wax around the windings has melted and the waxed paper wrappings are badly distorted.
This is not uncommon and I would not condemn a transformer just for looking a bit shabby. It might be generally sound internally where it matters; if it is not running excessively hot (indicative of shorted turns) I would retain it.

Quote:
I would welcome advice on replacing the metal rectifier
A UF4007 diode or any similar, plus a series resistor to replicate the forward resistance of the selenium rec. Others might have top-of-head experience of the ideal value. Many would disagree but if a selenium works OK (some do not, the resistance goes up with age) I tend to leave them in circuit.

Quote:
replace the 0.05uF and 1800pF caps with modern versions
If the 1800pF is a ceramic type it is unlikely to need replacing.

Quote:
Would adding some earth bonding between amp chassis, record deck chassis
With a fully isolated circuit it is arguably a very good idea. However, if one wants to be pedantic, one would note that modifying the safety arrangements away from the original manufacturer's design, puts the onus on the modifier to demonstrate suitability and compliance. When maintaining the original configuration, that onus is on the (defunct) manufacturer.
Re the transformer - thanks for advice. I shall se how it runs once I get to testing amp again.

Re the MR, which I believe is Selenium, I would be happy to leave as is. My concern was about the H&S concerns around Selenium. However, the MR looks in very good condition. So, I shall leave in place and think about replacing later.

Re the caps, the 0.05uF is a blue 'plastic' cylinder construction. The 1800pF looks like an old wire wound resistor. I was going to replace them because I do not recognise their construction - especially the 1800pF.

Good point about the earthing and bonding. I guess originally the mains in was 2 core as the mains transformer provided isolation. I was musing about bonding to reduce hum and perhaps give some added protection. As I shall never sell this player on I am only concerned with my own safety. As you say original manufacturer defunct so no possible claim there anyway

Barry
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Old 29th Apr 2022, 3:20 pm   #9
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Default Re: Dansette Bermuda Refurb

Here are photos of the 2 caps mentionedpreviously - unsure what type they are.

The blue one is definitely the 0.05uF but what type of construction is it?

The brown one is the 1800pF cap, I think. It is certainly occupying the position of the 1800pF in the cct dig. What type is that one?

All advice/comments welcome.

B
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Old 29th Apr 2022, 3:23 pm   #10
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by ms660 View Post
That schematic will get removed.....Forum rule B (8)

Lawrence.
The rule states: Do not post or request service data, or links to service data, if it is for sale at www.service-data.com. The service data website funds this forum. You may post a small section from published data (such as a section from a circuit diagram or other diagram) to illustrate or help with a discussion.

Please explain why my use of the extract from the service data I purchased contravened this rule. Thanks.
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Old 29th Apr 2022, 3:35 pm   #11
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Default Re: Dansette Bermuda Refurb

Quote:
The brown one is the 1800pF cap, I think. It is certainly occupying the position of the 1800pF in the cct dig. What type is that one?
It is ceramic and trustworthy.

Quote:
The blue one is definitely the 0.05uF but what type of construction is it
That one is mixed dielectric and not so trustworthy.
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Old 29th Apr 2022, 4:51 pm   #12
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by Mr_H_RetroTech View Post
Quote:
Originally Posted by Edward Huggins View Post
Yu will have great diificut t in fin a suiablester cartridges for the amplifier - the ideal one being a BSR X5H. You will need to use a simple Op-Amp (Pre-Amp) and take its power sut source from the EL84's cathede c.25V. Be careful you do not create an Earth Loop by connecting the amp chassis, motor plate and mains earth all together. The ideal cartrdhes is BSR T
Thanks for that. You are correct but I found a couple of Dansette refurb specialists on line who offer packages of stereo cartridges and preamp. So, I might try them.
Sorry, I sent my Post before I edited it! I meant to say that if you can source a BSR X5H, then that will be a 100% perfect option. Stereo safe and with no pre-amp needed. But they are as rare as hen's teeth at around £50-00.
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Old 29th Apr 2022, 6:18 pm   #13
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by Mr_H_RetroTech View Post
Quote:
Originally Posted by ms660 View Post
That schematic will get removed.....Forum rule B (8)

Lawrence.
The rule states: Do not post or request service data, or links to service data, if it is for sale at www.service-data.com. The service data website funds this forum. You may post a small section from published data (such as a section from a circuit diagram or other diagram) to illustrate or help with a discussion.

Please explain why my use of the extract from the service data I purchased contravened this rule. Thanks.
Because you posted a whole schematic (aka circuit diagram) which is available from this website via www.service-data.com as a download or whatever.

Lawrence.
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Old 30th Apr 2022, 3:49 pm   #14
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by Lucien Nunes View Post
Quote:
The brown one is the 1800pF cap, I think. It is certainly occupying the position of the 1800pF in the cct dig. What type is that one?
It is ceramic and trustworthy.

Quote:
The blue one is definitely the 0.05uF but what type of construction is it
That one is mixed dielectric and not so trustworthy.
Thanks for all the advice, much appreciated.

Trying to identify a suitable replacement for the blue 0.05uF 350V cap. Could you suggest a suitable alternative, please?
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Old 30th Apr 2022, 4:01 pm   #15
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by Edward Huggins View Post
Quote:
Originally Posted by Mr_H_RetroTech View Post
Quote:
Originally Posted by Edward Huggins View Post
Yu will have great diificut t in fin a suiablester cartridges for the amplifier - the ideal one being a BSR X5H. You will need to use a simple Op-Amp (Pre-Amp) and take its power sut source from the EL84's cathede c.25V. Be careful you do not create an Earth Loop by connecting the amp chassis, motor plate and mains earth all together. The ideal cartrdhes is BSR T
Thanks for that. You are correct but I found a couple of Dansette refurb specialists on line who offer packages of stereo cartridges and preamp. So, I might try them.
Sorry, I sent my Post before I edited it! I meant to say that if you can source a BSR X5H, then that will be a 100% perfect option. Stereo safe and with no pre-amp needed. But they are as rare as hen's teeth at around £50-00.
Thanks for all that info - great stuff and very helpful.

I sorted through some parts I salvaged from another BSR deck I had laying around and I found a BSR X5H cartridge. What are the chances? Anyway, once I have repaired the amp and put everything back together I shall try that cart - fingers crossed it will work. Thanks again you have been very helpful
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Old 30th Apr 2022, 4:05 pm   #16
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by JonSnell View Post
If you would like to send me the capacitor, please pm me first, I can restuff it for you, the contact spacing will line up with the current layout for ease of replacement and to keep it original looking.
If you bring a three core 3Amp mains cable into the chassis, live and neutral are as the old was but the earth connects directly to the chassis with a crimped eyelet, nut and bolt.

Nice little record players.
Thanks for the offer of restuffing that multistage cap. However, had a bit of a disaster removing it and ended up cutting it off (don't ask ). So in addition to replacing the electrolytics I need to make some PCB repairs. Luckily I can remember my PCB battle damage repair techniques from my RAF days, so no major deal

Thanks again
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Old 23rd May 2022, 4:36 pm   #17
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Default Re: Dansette Bermuda Refurb

Update on my Dansette Bermuda project for anyone interested. Recapped the amp and it works well. Good solid output through the BSR X5H cart I located. Only issues remaining are mechanical for which I need some hints, please..

The deck is a BSR Monarch UA 14. I degreased everything and relubed all the usual parts. Here's the but - although the platter rotates at just about the correct speed, when the tonearm auto lift/lower mechanism cuts in the platter grinds to a halt. If I rotate the platter by hand in the auto mode I can feel a definite resistance to rotation. Once the tone arm has lowered onto the record the resistance stops. The resistance is apparent again when the auto lift starts.

The main cam gear and trip pawl are nice and free. I have replaced the intermediate drive wheel with a NOS item.

Any ideas on what to do next much appreciated

Barry
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Old 23rd May 2022, 5:52 pm   #18
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Default Re: Dansette Bermuda Refurb

Usually down to a slipping drive wheel, even though you've replaced it, it may need redressing also clean the inside rim of the platter with methylated spirit and also the motor spindles
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Old 24th May 2022, 6:54 am   #19
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Default Re: Dansette Bermuda Refurb

Also, make absolutely certain that the end peg that engages with the groove in the underside of the cam is free to rotate, they often seize and can be missed. I generally heat them with my soldering iron until it rotates then plenty of isopropyl alcohol to clean out old lubricant, then a few drops of sewing machine oil does the trick, this will reduce the rotational friction when auto is engaged and may be all that's needed (Along with previous suggestions)
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Old 25th May 2022, 5:09 pm   #20
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Default Re: Dansette Bermuda Refurb

Quote:
Originally Posted by leslie5555 View Post
Usually down to a slipping drive wheel, even though you've replaced it, it may need redressing also clean the inside rim of the platter with methylated spirit and also the motor spindles
Thanks. I had cleaned the inside of the platter and the spindle but not dressed the drive wheel. Having done the latter the platter continues to rotate now during tonearm lift and lower but slows down markedly. So, those actions have kmproved matters but the lift/lower operation does not work correctly. There is some marked resistance to platter rotation during the tonearm lift/lower.
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