Regentone Handygram circuit help needed - UK Vintage Radio Repair and Restoration Discussion Forum

snappermart · 11th Oct 2017, 4:32 pm

Hello,

I am a newcomer here and in need of some help please !
I have a Regentone Handygram which has cleaned up really nicely and works well with the following issue. There is a green wax covered component that is attached to the volume pot that is overheating and begins to smoke after the unit has been powered for a minute or so. The problem I have is that there are no markings on it, so I have no idea what to replace it with !
I'd be grateful for any help !
Thanks

Ed_Dinning · 11th Oct 2017, 5:07 pm

Hi, that looks like a normal wirewound resistor. They normally run quite hot, but yours looks to have been getting excessively hot or catching on the cables beside it and causing them to smoke.

I don't have the circuit with me, but have any capacitors been changed? If not that may be cause of other parts overheating.

Ed

ms660 · 11th Oct 2017, 5:26 pm

Does the inside look like this with the same number of valves?(link for ID only):

https://picclick.co.uk/REGENTONE-HAN...618965495.html

Lawrence.

snappermart · 11th Oct 2017, 5:53 pm

Thanks for the swift replies 👍
Yes Lawrence, it looks the same as that .

ms660 · 11th Oct 2017, 7:18 pm

The two valves are probably a UY85 (rectifier valve) and a UL84 (amplification valve)

The green resistor looks as though it's the rectifier valves surge limiter, under normal conditions these tend to run from quite warm to hot depending on the circuit design.

Sometimes they can emit smoke if the player hasn't been used for a long time, in such circumstances the smoke is usually caused by dust/grease build up on the resistor due to a long period of inactivity.

A fault condition can also cause the resistor to get very hot and emit smoke, usually if there's a fault condition it will manifest it's self as distortion of the sound from the loudspeaker or as an excessive humming noise coming from the loudspeaker.

Lawrence.

snappermart · 11th Oct 2017, 7:54 pm

Thanks again Lawrence,
I have noticed that the heat has caused the plastic on the body of the player to melt which I guess indicates excessive heat is being produced and that there's a fault somewhere.

Edward Huggins · 12th Oct 2017, 8:40 am

Do you mean the outside plastic trim around the volume and tone controls under the speaker grill is melted? Are you hearing excessive hum or distortion as raised in Post #5? Also the UY85 does not look seated vertically into its valve holder.

snappermart · 12th Oct 2017, 7:22 pm

Hi Edward, I've attached a picture to show where the plastic has distorted due to the heat. I'll try reseating the valves and power it up again this evening to check for humming and distortion.
Thanks,
Martin

snappermart · 12th Oct 2017, 10:06 pm

OK, I've just powered the player up again after reseating the valves and tidying up some of the wiring. There is no humming or distortion (other than a bit of crackle on the volume pot when turning which I assume is dirt) However after a couple of minutes, something starts to produce smoke, though it is difficult to see which component its coming from as I don't want to run it too long in that state. Any further help would be greatly appreciated

Edward Huggins · 13th Oct 2017, 9:49 am

Ok, then this might be a fault in the main smoothing capacitor (to the right of the UL84) or its resisitor. If you feel you don't have the skill to undertake this, you could seek help from a member local to you - see the section for this on this site. The amplifier is very simple and should be an easy fix. I would not use this again until repaired.

Techman · 13th Oct 2017, 1:24 pm

After it's been run for a short time and something starts to smoke, un-plug the player completely from the mains and feel the aluminium can of the smoothing electrolytic capacitor for any signs of warming - it should feel cold, or perhaps I should say room temperature. If it feels slightly warm, especially after several switch on and offs, then it's likely to be internally electrically leaky and will need replacing - they go off with a bit of a bang if they become very hot due to leakage!

snappermart · 13th Oct 2017, 4:14 pm

Thanks for all the advice chaps !
I'll see if there's someone nearby who might be able to help.
I'm a bit of a tinkerer at heart and keen to learn but due to dangerous voltages in these old players I think I'd best seek some expert help.
Many thanks again to everyone who took the time to post a reply !

Martin

11th Oct 2017, 4:32 pm	#1
snappermart Retired Dormant Member Join Date: Oct 2017 Location: Blackpool, Lancashire, UK. Posts: 6	Regentone Handygram circuit help needed Hello, I am a newcomer here and in need of some help please ! I have a Regentone Handygram which has cleaned up really nicely and works well with the following issue. There is a green wax covered component that is attached to the volume pot that is overheating and begins to smoke after the unit has been powered for a minute or so. The problem I have is that there are no markings on it, so I have no idea what to replace it with ! I'd be grateful for any help ! Thanks Attached Thumbnails

11th Oct 2017, 5:07 pm	#2
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Regentone Handygram circuit help needed Hi, that looks like a normal wirewound resistor. They normally run quite hot, but yours looks to have been getting excessively hot or catching on the cables beside it and causing them to smoke. I don't have the circuit with me, but have any capacitors been changed? If not that may be cause of other parts overheating. Ed

11th Oct 2017, 5:26 pm	#3
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Regentone Handygram circuit help needed Does the inside look like this with the same number of valves?(link for ID only): https://picclick.co.uk/REGENTONE-HAN...618965495.html Lawrence.

11th Oct 2017, 5:53 pm	#4
snappermart Retired Dormant Member Join Date: Oct 2017 Location: Blackpool, Lancashire, UK. Posts: 6	Re: Regentone Handygram circuit help needed Thanks for the swift replies 👍 Yes Lawrence, it looks the same as that .

11th Oct 2017, 7:54 pm	#6
snappermart Retired Dormant Member Join Date: Oct 2017 Location: Blackpool, Lancashire, UK. Posts: 6	Re: Regentone Handygram circuit help needed Thanks again Lawrence, I have noticed that the heat has caused the plastic on the body of the player to melt which I guess indicates excessive heat is being produced and that there's a fault somewhere.

11th Oct 2017, 7:18 pm	#5
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Regentone Handygram circuit help needed The two valves are probably a UY85 (rectifier valve) and a UL84 (amplification valve) The green resistor looks as though it's the rectifier valves surge limiter, under normal conditions these tend to run from quite warm to hot depending on the circuit design. Sometimes they can emit smoke if the player hasn't been used for a long time, in such circumstances the smoke is usually caused by dust/grease build up on the resistor due to a long period of inactivity. A fault condition can also cause the resistor to get very hot and emit smoke, usually if there's a fault condition it will manifest it's self as distortion of the sound from the loudspeaker or as an excessive humming noise coming from the loudspeaker. Lawrence.

12th Oct 2017, 8:40 am	#7
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,335	Re: Regentone Handygram circuit help needed Do you mean the outside plastic trim around the volume and tone controls under the speaker grill is melted? Are you hearing excessive hum or distortion as raised in Post #5? Also the UY85 does not look seated vertically into its valve holder. __________________ Edward.

12th Oct 2017, 7:22 pm	#8
snappermart Retired Dormant Member Join Date: Oct 2017 Location: Blackpool, Lancashire, UK. Posts: 6	Re: Regentone Handygram circuit help needed Hi Edward, I've attached a picture to show where the plastic has distorted due to the heat. I'll try reseating the valves and power it up again this evening to check for humming and distortion. Thanks, Martin Attached Thumbnails

12th Oct 2017, 10:06 pm	#9
snappermart Retired Dormant Member Join Date: Oct 2017 Location: Blackpool, Lancashire, UK. Posts: 6	Re: Regentone Handygram circuit help needed OK, I've just powered the player up again after reseating the valves and tidying up some of the wiring. There is no humming or distortion (other than a bit of crackle on the volume pot when turning which I assume is dirt) However after a couple of minutes, something starts to produce smoke, though it is difficult to see which component its coming from as I don't want to run it too long in that state. Any further help would be greatly appreciated

13th Oct 2017, 9:49 am	#10
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,335	Re: Regentone Handygram circuit help needed Ok, then this might be a fault in the main smoothing capacitor (to the right of the UL84) or its resisitor. If you feel you don't have the skill to undertake this, you could seek help from a member local to you - see the section for this on this site. The amplifier is very simple and should be an easy fix. I would not use this again until repaired. __________________ Edward.

13th Oct 2017, 1:24 pm	#11
Techman Dekatron Join Date: Nov 2009 Location: Lincolnshire, UK. Posts: 5,000	Re: Regentone Handygram circuit help needed After it's been run for a short time and something starts to smoke, un-plug the player completely from the mains and feel the aluminium can of the smoothing electrolytic capacitor for any signs of warming - it should feel cold, or perhaps I should say room temperature. If it feels slightly warm, especially after several switch on and offs, then it's likely to be internally electrically leaky and will need replacing - they go off with a bit of a bang if they become very hot due to leakage!

13th Oct 2017, 4:14 pm	#12
snappermart Retired Dormant Member Join Date: Oct 2017 Location: Blackpool, Lancashire, UK. Posts: 6	Re: Regentone Handygram circuit help needed Thanks for all the advice chaps ! I'll see if there's someone nearby who might be able to help. I'm a bit of a tinkerer at heart and keen to learn but due to dangerous voltages in these old players I think I'd best seek some expert help. Many thanks again to everyone who took the time to post a reply ! Martin