Dansette Severn - UK Vintage Radio Repair and Restoration Discussion Forum

roadster · 27th Nov 2018, 1:20 pm

I have acquired a Dansette Severn to play with / practice on / refurb

it's a real mess and unworking apparently.

I can find very little information on this model. Is there a schematic or any other information available for it or of any other similar model?

Station X · 27th Nov 2018, 1:31 pm

Dansettes used very similar circuits in a number of models.

I can see two valves. What is the valve line up and cartridge type?

roadster · 27th Nov 2018, 2:37 pm

I'm just having trouble getting the 4 rusty screws out of the surround that holds the turntable in so I can have a good look. I may have to drill 2 of them out. It looks like the whole thing has been damp at some time.

Edward Huggins · 27th Nov 2018, 3:09 pm

This uses the ubiquitous UL84/UY85 live chassis combo and a BSR X5H stereo-compatible cartridge. The speaker in these is an unusual sized 8" x 4" unit.

Station X · 27th Nov 2018, 3:21 pm

Quote:

Originally Posted by roadster

I'm just having trouble getting the 4 rusty screws out of the surround that holds the turntable in so I can have a good look. I may have to drill 2 of them out. It looks like the whole thing has been damp at some time.

You may be able to reach under the turntable and flip the toggles on the transit screws. The rear slotted panel may be a separate piece or you may be able to fold it forward. The valves are accessible as the player stands.

roadster · 27th Nov 2018, 8:53 pm

Thanks all. My ALDI version of a Dremmel literally fell apart in my hands as I was cutting a slot in the first screw head. I can't get access without taking the deck out, its jammed solid anyway so needs de greasing and lubricating.

roadster · 29th Nov 2018, 4:28 pm

The story goes that the original owner told me that there was a wisp of smoke and it stopped. He took it to a repair shop and it ran for a while then it did the same. I can't see any burn marks or any sign of a previous repair. When I get to the stage of getting the electrics detached from the cabinet should I try plugging it in? I have an RCD I can plug it in to.

It is the UL84/UY85

I have basic electronic knowledge from many years ago and my old but trusty analogue Ammeter

I'm just struggling to get the last nut off the speaker, it's just turning, and then it will all be free.

Station X · 29th Nov 2018, 4:51 pm

The circuit will be similar to the Dansette Popular. You can download it here:-

https://www.service-data.com/product...15/1521/a11115

The first thing to check is whether HT is present on the smoothing capacitors.

roadster · 30th Nov 2018, 10:31 pm

I risked a switch on, no drama, the motor is on constantly which I believe is correct but I have some mechanical issues which I am addressing. Mainly sticky horrible grease over everything. Both valves light up.

However, there is no sound coming from the speaker when I run my finger over the stylus nor any hum.

Station X · 30th Nov 2018, 11:33 pm

See post #8.

roadster · 1st Dec 2018, 12:26 am

Quote:

Originally Posted by Station X

See post #8.

May I ask what values should I expect and what should I set my meter to?

I have only basic knowledge of electronics. I started of as an adding machine engineer

John10b · 1st Dec 2018, 10:28 am

Hi, post #4 tells you valve type, post #8 gives info on how to obtain circuit diagram, which is well worth you obtaining.
What type of meter do you have?
Cheers
John

Station X · 1st Dec 2018, 11:26 am

I posted an extract from the circuit in post #8. This will be enough to get you started and will guide other members giving you advice.

Set your meter to measure DC volts. Connect the negative lead of your meter to the negative land of the Printed Circuit Board (PCB). This will be the point which the can of the smoothing capacitors is connected to. I believe this is the land at the bottom left hand corner of your picture in post #7, but the picture is unclear in this area.

Switch on check that the valves light up and allow a couple of minutes for them to warm up. Now use your meter's positive lead to probe each end of the 12k resistor (Colour coded Brown, Red, Orange) in turn. The two readings should be in hundreds of volts. Post the results here and we'll advise you further.

roadster · 1st Dec 2018, 12:46 pm

Thanks for your patience.

Yes I downloaded the circuit diagram.

My meter is RS Components branded Robin analogue Multimeter model OM 500T

The voltage readings are 290 and 220 . I think from the circuit diagram that 290 is the C4 and C1 end of the resistor and 220 is the C3 end.

Station X · 1st Dec 2018, 1:43 pm

Those readings are good, assuming they're in volts? They prove that the UY85 rectifier valve is working and that HT voltage is present.

Please take a reading across R1 330R (Orange, Orange Brown), the cathode resistor. Expect just a few volts here.

John10b · 1st Dec 2018, 1:47 pm

Hi again, in post #11 you asked for values, sorry I misread that as valves hence my reply, bit early in the morning, for me.
Getting the circuit diagram is always a good place to start.
Cheers
John

roadster · 1st Dec 2018, 2:23 pm

Quote:

Originally Posted by Station X

Those readings are good, assuming they're in volts? They prove that the UY85 rectifier valve is working and that HT voltage is present.

Please take a reading across R1 330R (Orange, Orange Brown), the cathode resistor. Expect just a few volts here.

That reading is 20 Volts

Station X · 1st Dec 2018, 2:33 pm

That indicates a combined anode and screen current for the UL84 of 330/20 which is approximately 60mA and is good.

Do you hear anything from the speaker if you touch the centre tag of the volume control potentiometer with a screwdriver blade? Make sure not to short this tag to the mains switch which is ganged with the volume control.

If you hear nothing, check the loudspeaker coil and secondary winding of the output transformer for continuity. You'll need to disconnect one speaker lead to do this.

ms660 · 1st Dec 2018, 4:03 pm

290v at the reservoir at 60mA load current seems a bit high to me for mains voltage feed to the rectifier via 175 ohm surge limiter.

Lawrence.

Station X · 1st Dec 2018, 4:10 pm

When the OP returns I'll suggest he checks the value of all the resistors.

27th Nov 2018, 1:31 pm	#2
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Dansette Severn Dansettes used very similar circuits in a number of models. I can see two valves. What is the valve line up and cartridge type? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

27th Nov 2018, 2:37 pm	#3
roadster Triode Join Date: Nov 2018 Location: Smeeton Westerby, Leicestershire, UK. Posts: 20	Re: Dansette Severn I'm just having trouble getting the 4 rusty screws out of the surround that holds the turntable in so I can have a good look. I may have to drill 2 of them out. It looks like the whole thing has been damp at some time.

27th Nov 2018, 8:53 pm	#6
roadster Triode Join Date: Nov 2018 Location: Smeeton Westerby, Leicestershire, UK. Posts: 20	Re: Dansette Severn Thanks all. My ALDI version of a Dremmel literally fell apart in my hands as I was cutting a slot in the first screw head. I can't get access without taking the deck out, its jammed solid anyway so needs de greasing and lubricating.

30th Nov 2018, 10:31 pm	#9
roadster Triode Join Date: Nov 2018 Location: Smeeton Westerby, Leicestershire, UK. Posts: 20	Re: Dansette Severn I risked a switch on, no drama, the motor is on constantly which I believe is correct but I have some mechanical issues which I am addressing. Mainly sticky horrible grease over everything. Both valves light up. However, there is no sound coming from the speaker when I run my finger over the stylus nor any hum.

30th Nov 2018, 11:33 pm	#10
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Dansette Severn See post #8. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

27th Nov 2018, 1:20 pm	#1
roadster Triode Join Date: Nov 2018 Location: Smeeton Westerby, Leicestershire, UK. Posts: 20	Dansette Severn I have acquired a Dansette Severn to play with / practice on / refurb it's a real mess and unworking apparently. I can find very little information on this model. Is there a schematic or any other information available for it or of any other similar model? Attached Thumbnails

27th Nov 2018, 3:09 pm	#4
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,328	Re: Dansette Severn This uses the ubiquitous UL84/UY85 live chassis combo and a BSR X5H stereo-compatible cartridge. The speaker in these is an unusual sized 8" x 4" unit. __________________ Edward.

29th Nov 2018, 4:28 pm	#7
roadster Triode Join Date: Nov 2018 Location: Smeeton Westerby, Leicestershire, UK. Posts: 20	Re: Dansette Severn The story goes that the original owner told me that there was a wisp of smoke and it stopped. He took it to a repair shop and it ran for a while then it did the same. I can't see any burn marks or any sign of a previous repair. When I get to the stage of getting the electrics detached from the cabinet should I try plugging it in? I have an RCD I can plug it in to. It is the UL84/UY85 I have basic electronic knowledge from many years ago and my old but trusty analogue Ammeter I'm just struggling to get the last nut off the speaker, it's just turning, and then it will all be free. Attached Thumbnails

29th Nov 2018, 4:51 pm	#8
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Dansette Severn The circuit will be similar to the Dansette Popular. You can download it here:- https://www.service-data.com/product...15/1521/a11115 The first thing to check is whether HT is present on the smoothing capacitors. Attached Thumbnails __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

1st Dec 2018, 10:28 am	#12
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette Severn Hi, post #4 tells you valve type, post #8 gives info on how to obtain circuit diagram, which is well worth you obtaining. What type of meter do you have? Cheers John

1st Dec 2018, 11:26 am	#13
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Dansette Severn I posted an extract from the circuit in post #8. This will be enough to get you started and will guide other members giving you advice. Set your meter to measure DC volts. Connect the negative lead of your meter to the negative land of the Printed Circuit Board (PCB). This will be the point which the can of the smoothing capacitors is connected to. I believe this is the land at the bottom left hand corner of your picture in post #7, but the picture is unclear in this area. Switch on check that the valves light up and allow a couple of minutes for them to warm up. Now use your meter's positive lead to probe each end of the 12k resistor (Colour coded Brown, Red, Orange) in turn. The two readings should be in hundreds of volts. Post the results here and we'll advise you further. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

1st Dec 2018, 12:46 pm	#14
roadster Triode Join Date: Nov 2018 Location: Smeeton Westerby, Leicestershire, UK. Posts: 20	Re: Dansette Severn Thanks for your patience. Yes I downloaded the circuit diagram. My meter is RS Components branded Robin analogue Multimeter model OM 500T The voltage readings are 290 and 220 . I think from the circuit diagram that 290 is the C4 and C1 end of the resistor and 220 is the C3 end.

1st Dec 2018, 1:43 pm	#15
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Dansette Severn Those readings are good, assuming they're in volts? They prove that the UY85 rectifier valve is working and that HT voltage is present. Please take a reading across R1 330R (Orange, Orange Brown), the cathode resistor. Expect just a few volts here. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

1st Dec 2018, 1:47 pm	#16
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette Severn Hi again, in post #11 you asked for values, sorry I misread that as valves hence my reply, bit early in the morning, for me. Getting the circuit diagram is always a good place to start. Cheers John

1st Dec 2018, 2:33 pm	#18
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Dansette Severn That indicates a combined anode and screen current for the UL84 of 330/20 which is approximately 60mA and is good. Do you hear anything from the speaker if you touch the centre tag of the volume control potentiometer with a screwdriver blade? Make sure not to short this tag to the mains switch which is ganged with the volume control. If you hear nothing, check the loudspeaker coil and secondary winding of the output transformer for continuity. You'll need to disconnect one speaker lead to do this. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

1st Dec 2018, 4:03 pm	#19
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Dansette Severn 290v at the reservoir at 60mA load current seems a bit high to me for mains voltage feed to the rectifier via 175 ohm surge limiter. Lawrence. Last edited by ms660; 1st Dec 2018 at 4:10 pm. Reason: Re-wrote

1st Dec 2018, 4:10 pm	#20
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Dansette Severn When the OP returns I'll suggest he checks the value of all the resistors. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.