Burned out mains transformer - UK Vintage Radio Repair and Restoration Discussion Forum

retroaudio · 2nd Oct 2017, 5:27 pm

Hi,

I have a Ever Ready 1935 5016 which I had not used for a while. It lives in an unheated shed and I suspect retrospectively it may have had green spot in the transformer, After being on a low volume for about two hours there was a smell of burning wax and before I could do anything further there was smoke coming from the transformer, The rectifier is I believe a full wave rectifier A11D which has a Mullard equivalent. My question is would it be better to get someone to rewind the transformer and make sure all the other component which could damage mains transformer are OK or would it be better to try and get a equivalent from a scrap set and do the necessary checks. The checks are just in case it wasn't green spot

thanks Alex

PJL · 2nd Oct 2017, 5:35 pm

Green spot will not be your problem as that results in open circuit windings and no power. Something must have failed, maybe the rectifier or output valve?

Graham G3ZVT · 2nd Oct 2017, 6:18 pm

Surely it could have gone shorted turns, and not involved any other component?

Ed_Dinning · 2nd Oct 2017, 7:15 pm

Hi Alex, can you post a picture of the transformer with some dimensions and voltages?

If you are not concerned about originality there may be a suitable one available that would be much cheaper than a rewind.

Ed

PJL · 2nd Oct 2017, 10:21 pm

Copper carbonate is not a conductor.

Mike. Watterson · 3rd Oct 2017, 9:03 am

More likely a leaky grid capacitor

Mike. Watterson · 3rd Oct 2017, 9:22 am

Probably more squared off case version of the Lissen 8216:-

http://www.radiomuseum.org/r/lissen_8216.html

I have the Ever Ready 5017.

The transformer generally only burns out if something else is faulty.

2nd Oct 2017, 5:27 pm	#1
retroaudio Pentode Join Date: Mar 2005 Location: Cairneyhill, Fife, UK. Posts: 135	Burned out mains transformer Hi, I have a Ever Ready 1935 5016 which I had not used for a while. It lives in an unheated shed and I suspect retrospectively it may have had green spot in the transformer, After being on a low volume for about two hours there was a smell of burning wax and before I could do anything further there was smoke coming from the transformer, The rectifier is I believe a full wave rectifier A11D which has a Mullard equivalent. My question is would it be better to get someone to rewind the transformer and make sure all the other component which could damage mains transformer are OK or would it be better to try and get a equivalent from a scrap set and do the necessary checks. The checks are just in case it wasn't green spot thanks Alex

2nd Oct 2017, 5:35 pm	#2
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: burned out mains transformer Green spot will not be your problem as that results in open circuit windings and no power. Something must have failed, maybe the rectifier or output valve?

2nd Oct 2017, 6:18 pm	#3
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 18,724	Re: burned out mains transformer Surely it could have gone shorted turns, and not involved any other component? __________________ -- Graham. G3ZVT Last edited by Graham G3ZVT; 2nd Oct 2017 at 6:33 pm.

2nd Oct 2017, 7:15 pm	#4
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Burned out mains transformer Hi Alex, can you post a picture of the transformer with some dimensions and voltages? If you are not concerned about originality there may be a suitable one available that would be much cheaper than a rewind. Ed

2nd Oct 2017, 10:21 pm	#5
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Burned out mains transformer Copper carbonate is not a conductor.

3rd Oct 2017, 9:03 am	#6
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: Burned out mains transformer More likely a leaky grid capacitor

3rd Oct 2017, 9:22 am	#7
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: Burned out mains transformer Probably more squared off case version of the Lissen 8216:- http://www.radiomuseum.org/r/lissen_8216.html I have the Ever Ready 5017. The transformer generally only burns out if something else is faulty.