Dansette Bermuda MK II ?? - Page 10 - UK Vintage Radio Repair and Restoration Discussion Forum

martinpinner · 5th Mar 2018, 5:15 pm

The readings on the valves already given were DC !!!

Station X · 5th Mar 2018, 5:20 pm

AC only applies to pins 4 and 5.

martinpinner · 5th Mar 2018, 5:48 pm

I will check this later this week and advise.

martinpinner · 6th Mar 2018, 5:42 pm

Valve UCL82 removed and connected to the heater only.The volt readings are:
Pin1 -0.003
Pin2 -0.002
Pin3 -0.009
Pin6 0.22
Pin7 0.204
Pin8 -0.024
Pin9 0.210

Station X · 6th Mar 2018, 5:46 pm

I assume that UY85 was still in position, that power was applied and that both valve's heaters lit up?

martinpinner · 6th Mar 2018, 7:17 pm

Yes Uy89 was in position, power on and both heated up.

Station X · 6th Mar 2018, 7:26 pm

We are going round in circles here.

Do you have an AC voltage on pin 9 of the UY85?

Do you have a DC voltage on each of the three smoothing capacitors?

All voltages measured w.r.t to chassis.

martinpinner · 6th Mar 2018, 8:44 pm

Post 101 gives readings of The Can with the smoothing capacitors.
Will check Ac Voltage on Pin 9 UY85 tomorrow.

Station X · 6th Mar 2018, 9:12 pm

If you STILL have the same, or approximately the same, voltages on the can as stated in post #101 then there's no need to check pin 9 of the UY85.

If you haven't checked the can voltages since you connected the UCL82 using flying leads to the heater you need to do so.

Assuming the voltages are in order, what DC voltage do you get at each end of the 12k resistor and at each end of the 100k resistor measured w.r.t chassis?

martinpinner · 7th Mar 2018, 11:58 am

The Can voltages are not the same and are 3.05, 3.20 and 0.45 volts.

The AC voltage on pin 9 of UY85 is 70 volts.

Station X · 7th Mar 2018, 12:06 pm

Remove both valves and again check the AC voltage at pin 9 of the UY85. It should be close to the mains voltage. If it is, then you most likely have a near short across the HT.

martinpinner · 7th Mar 2018, 12:38 pm

Valve UCL82 is already removed and connected to pins 4 and 5 only. Do you mean for these to be disconnected? How long should the player be switched off before removing a valve.
It had been off for about 20 mins but when removing UY85 I got a shock.

What is a short across the HT?

Station X · 7th Mar 2018, 12:47 pm

The valves both need to be removed and any flying leads disconnected before carrying out the test mentioned in post #191. This prevents any fault in the UY85 pulling down the AC voltage at pin 9. It will also the prevent HT (High Tension) voltage being supplied to the rest of the circuit which could be pulling down both the AC and HT voltages.

If you got a shock when removing the valve after 20 minutes, then this points to the smoothing capacitors being in good order.

A short is a short circuit.

martinpinner · 7th Mar 2018, 1:04 pm

It reads 22.2Volts.

Station X · 7th Mar 2018, 1:09 pm

I'm very sorry, but I cannot help you with this any more. The test results you're posting are totally inconsistent.

I suggest you seek help from an experienced forum member living nearby.

martinpinner · 7th Mar 2018, 1:33 pm

Thanks for your help in trying to get it working properly. I just took a reading again on the 100R resistor connected to pin 9 as it sparked when taking the readings and this now only measures 47.9. Is a 100Kohms metal film resistor OK to replace with. I will then put it back together and seek help locally.

Perhaps you could just confirm for me that when readings are taken that it is normal for them to fluctuate up and down before finally becoming nearly settled and a reading taken.

Thanks to everyone who helped me in trying to get amplified sound.

Martin

Station X · 7th Mar 2018, 1:40 pm

You cannot replace a 100R resistor with a 100k resistor, it's 1000 times too big.

If there's capacitance in a circuit then, when measuring resistance, it's usual for the meter to take time to settle down as initially it will just be charging the capacitors.

I don't recollect seeing a meter fluctuating up and down though, unless the measured voltage is also fluctuating.

ms660 · 7th Mar 2018, 1:41 pm

I wouldn't bother replacing anything, just take it to the same person that repaired the Hacker Cavalier for you.

Lawrence.

Techman · 7th Mar 2018, 2:41 pm

This thread has really made me shudder.

I gather the amplifier was working originally and just needed a couple of capacitors replacing for future reliability.

Without checking back, I seem to remember that there was a 'watty' dropper that hadn't been properly soldered.

It seems that mistakes may have been made when removing components without taking proper note of where they were originally connected.

At one point I even wondered whether the valve pins were being counted the right way round for the voltage readings as some of them made no sense at all.

Before completely giving up on this altogether, I think it would be worth checking that the meter (DVM) is still working properly and giving correct readings by checking it against a known voltage source on the DC ranges being used - a known good 9 volt PP3 battery would be the safest way. I say this as I note in a previous post that the meter has shorted out the mains supply on the 10 amp range, blowing the house trip. This range will be un-fused - only the 200mA and below current ranges are usually protected by a fuse.

Martin has done his best with this player, having obviously very little experience of such things and has stuck with it and followed advice as best he could. I have to admit that I resisted getting involved with this thread and feared there was going to be an accident at one point. Perhaps it IS time to take it to someone else to repair, but I would still check the accuracy of that DVM.

martinpinner · 7th Mar 2018, 3:27 pm

Thanks for your response.I did check the meter as you suggested yesterday and it is OK.
You are right I am a novice at this and it has turned out to be a problem. In most cases I took photo's before disconnecting components but have removed some capacitors that may have been bridged across another PCB track.These are still an unknown.

I have read the valve pins correctly(clockwise) and as mentioned in my earlier post When taking measurements I dis get a lot of fluctuating on the readings before it became more or less settled. I am putting it back together and will seek someone to continue with it although I am disappointed that I could not complete it myself.

Martin

It was working at the outset although the volume was not great but probably a new stylus would have improved this.The auto changer is working but just needs fine tuning.

5th Mar 2018, 5:15 pm	#181
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? The readings on the valves already given were DC !!!

5th Mar 2018, 5:20 pm	#182
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? AC only applies to pins 4 and 5. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

5th Mar 2018, 5:48 pm	#183
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? I will check this later this week and advise.

6th Mar 2018, 5:42 pm	#184
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? Valve UCL82 removed and connected to the heater only.The volt readings are: Pin1 -0.003 Pin2 -0.002 Pin3 -0.009 Pin6 0.22 Pin7 0.204 Pin8 -0.024 Pin9 0.210

6th Mar 2018, 5:46 pm	#185
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? I assume that UY85 was still in position, that power was applied and that both valve's heaters lit up? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

6th Mar 2018, 7:17 pm	#186
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? Yes Uy89 was in position, power on and both heated up.

6th Mar 2018, 7:26 pm	#187
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? We are going round in circles here. Do you have an AC voltage on pin 9 of the UY85? Do you have a DC voltage on each of the three smoothing capacitors? All voltages measured w.r.t to chassis. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

6th Mar 2018, 8:44 pm	#188
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? Post 101 gives readings of The Can with the smoothing capacitors. Will check Ac Voltage on Pin 9 UY85 tomorrow.

6th Mar 2018, 9:12 pm	#189
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? If you STILL have the same, or approximately the same, voltages on the can as stated in post #101 then there's no need to check pin 9 of the UY85. If you haven't checked the can voltages since you connected the UCL82 using flying leads to the heater you need to do so. Assuming the voltages are in order, what DC voltage do you get at each end of the 12k resistor and at each end of the 100k resistor measured w.r.t chassis? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

7th Mar 2018, 11:58 am	#190
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? The Can voltages are not the same and are 3.05, 3.20 and 0.45 volts. The AC voltage on pin 9 of UY85 is 70 volts.

7th Mar 2018, 12:06 pm	#191
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? Remove both valves and again check the AC voltage at pin 9 of the UY85. It should be close to the mains voltage. If it is, then you most likely have a near short across the HT. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

7th Mar 2018, 12:38 pm	#192
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? Valve UCL82 is already removed and connected to pins 4 and 5 only. Do you mean for these to be disconnected? How long should the player be switched off before removing a valve. It had been off for about 20 mins but when removing UY85 I got a shock. What is a short across the HT?

7th Mar 2018, 12:47 pm	#193
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? The valves both need to be removed and any flying leads disconnected before carrying out the test mentioned in post #191. This prevents any fault in the UY85 pulling down the AC voltage at pin 9. It will also the prevent HT (High Tension) voltage being supplied to the rest of the circuit which could be pulling down both the AC and HT voltages. If you got a shock when removing the valve after 20 minutes, then this points to the smoothing capacitors being in good order. A short is a short circuit. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

7th Mar 2018, 1:04 pm	#194
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? It reads 22.2Volts.

7th Mar 2018, 1:09 pm	#195
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? I'm very sorry, but I cannot help you with this any more. The test results you're posting are totally inconsistent. I suggest you seek help from an experienced forum member living nearby. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

7th Mar 2018, 1:33 pm	#196
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? Thanks for your help in trying to get it working properly. I just took a reading again on the 100R resistor connected to pin 9 as it sparked when taking the readings and this now only measures 47.9. Is a 100Kohms metal film resistor OK to replace with. I will then put it back together and seek help locally. Perhaps you could just confirm for me that when readings are taken that it is normal for them to fluctuate up and down before finally becoming nearly settled and a reading taken. Thanks to everyone who helped me in trying to get amplified sound. Martin

7th Mar 2018, 1:40 pm	#197
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dansette Bermuda MK II ?? You cannot replace a 100R resistor with a 100k resistor, it's 1000 times too big. If there's capacitance in a circuit then, when measuring resistance, it's usual for the meter to take time to settle down as initially it will just be charging the capacitors. I don't recollect seeing a meter fluctuating up and down though, unless the measured voltage is also fluctuating. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

7th Mar 2018, 1:41 pm	#198
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Dansette Bermuda MK II ?? I wouldn't bother replacing anything, just take it to the same person that repaired the Hacker Cavalier for you. Lawrence.

7th Mar 2018, 2:41 pm	#199
Techman Dekatron Join Date: Nov 2009 Location: Lincolnshire, UK. Posts: 5,000	Re: Dansette Bermuda MK II ?? This thread has really made me shudder. I gather the amplifier was working originally and just needed a couple of capacitors replacing for future reliability. Without checking back, I seem to remember that there was a 'watty' dropper that hadn't been properly soldered. It seems that mistakes may have been made when removing components without taking proper note of where they were originally connected. At one point I even wondered whether the valve pins were being counted the right way round for the voltage readings as some of them made no sense at all. Before completely giving up on this altogether, I think it would be worth checking that the meter (DVM) is still working properly and giving correct readings by checking it against a known voltage source on the DC ranges being used - a known good 9 volt PP3 battery would be the safest way. I say this as I note in a previous post that the meter has shorted out the mains supply on the 10 amp range, blowing the house trip. This range will be un-fused - only the 200mA and below current ranges are usually protected by a fuse. Martin has done his best with this player, having obviously very little experience of such things and has stuck with it and followed advice as best he could. I have to admit that I resisted getting involved with this thread and feared there was going to be an accident at one point. Perhaps it IS time to take it to someone else to repair, but I would still check the accuracy of that DVM.

7th Mar 2018, 3:27 pm	#200
martinpinner Hexode Join Date: Oct 2015 Location: Sheffield, South Yorkshire, UK. Posts: 252	Re: Dansette Bermuda MK II ?? Thanks for your response.I did check the meter as you suggested yesterday and it is OK. You are right I am a novice at this and it has turned out to be a problem. In most cases I took photo's before disconnecting components but have removed some capacitors that may have been bridged across another PCB track.These are still an unknown. I have read the valve pins correctly(clockwise) and as mentioned in my earlier post When taking measurements I dis get a lot of fluctuating on the readings before it became more or less settled. I am putting it back together and will seek someone to continue with it although I am disappointed that I could not complete it myself. Martin It was working at the outset although the volume was not great but probably a new stylus would have improved this.The auto changer is working but just needs fine tuning.