RS "Heavy Duty" Output Transformer - UK Vintage Radio Repair and Restoration Discussion Forum

mole42uk · 28th May 2014, 10:33 am

Hi,

Has anyone got a copy of the data sheet suppled with the RS "Heavy Duty" Output Transformer? I have a transformer that came out of an ECL84 P-P amplifier butr I wonder what else it will do?

Thanks,

GrimJosef · 28th May 2014, 10:54 am

One thing it may do is to earn a very decent financial return if you should choose to sell it. In the early days of Marshall guitar amplifiers they routinely used stock RS transformers. In some cases these were driven well past their rated capacity to get the kind of overload distortion that the guitarists liked. Now, when the obvious consequences of seriously overloading something duly come to pass, the owner of the amplifier will look around for a replacement. These early amps are worth a lot of money and the owner will not want to devalue his amp by using the 'wrong' transformer. If yours is one of the 'right' ones https://www.ig-transformatoren.com/m...nsformers.html he may well pay over the odds for it.

Cheers,

GJ

mole42uk · 28th May 2014, 11:20 am

Well, that would be a good thing since it looks too small for me to use in my latest project, but I don't see 'my' transformer on that page. I've attached a photo of mine.

Dave757 · 29th May 2014, 1:23 am

Quote:

Originally Posted by mole42uk

Has anyone got a copy of the data sheet suppled with the RS "Heavy Duty" Output Transformer?

Hi

Is this any use?

Kind regards

Dave

mole42uk · 29th May 2014, 6:45 am

Hi,
I have that one - it's surprising that the price was so low!!

There is a data sheet that was supplied with the RS output transformers showing how to connect the various taps to achieve the different ratios.

Phil G4SPZ · 29th May 2014, 6:04 pm

I have a 'pair', from which you may be able to deduce sufficient data! See the attached photos which I hope will be helpful. Your transformer appears to be the same as the upper one in the pictures below.

One transformer is an RS "Heavy Duty", the other is an RS "EL84" transformer which, crucially, has the connection data printed on it. I realise that the impedances are different, but the pin-outs may just be the same. The frame is slightly deeper on the Heavy Duty version but to all intents and purposes they look similar in other respects.

Phil

mole42uk · 29th May 2014, 7:03 pm

Thanks Phil. I think I have the same one as your "Heavy Duty"

My understanding is that the "EL84" and the "Heavy Duty" are essentially the same 15W transformer, except that the "EL84" has 43% taps on the primary for UL use as described on the label for yours. I will look at mine tomorrow and see if it has different windings to the "EL84" in your picture.

Steve_Bell · 29th May 2014, 10:20 pm

Do these pages give you what you want?

http://www.hifiworks.co.uk/images_fu...%20output1.jpg
http://www.hifiworks.co.uk/images_fu...%20output2.jpg
http://www.hifiworks.co.uk/images_fu...%20output3.jpg
http://www.hifiworks.co.uk/images_fu...%20output4.jpg

regards,
Steve.

mole42uk · 30th May 2014, 7:30 am

Perfect!
Thank you.

28th May 2014, 10:33 am	#1
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,608	RS "Heavy Duty" Output Transformer Hi, Has anyone got a copy of the data sheet suppled with the RS "Heavy Duty" Output Transformer? I have a transformer that came out of an ECL84 P-P amplifier butr I wonder what else it will do? Thanks, __________________ Richard Index: recursive loop: see recursive loop

28th May 2014, 10:54 am	#2
GrimJosef Dekatron Join Date: Sep 2007 Location: Oxfordshire, UK. Posts: 4,311	Re: RS "Heavy Duty" Output Transformer One thing it may do is to earn a very decent financial return if you should choose to sell it. In the early days of Marshall guitar amplifiers they routinely used stock RS transformers. In some cases these were driven well past their rated capacity to get the kind of overload distortion that the guitarists liked. Now, when the obvious consequences of seriously overloading something duly come to pass, the owner of the amplifier will look around for a replacement. These early amps are worth a lot of money and the owner will not want to devalue his amp by using the 'wrong' transformer. If yours is one of the 'right' ones https://www.ig-transformatoren.com/m...nsformers.html he may well pay over the odds for it. Cheers, GJ __________________ http://www.ampregen.com

28th May 2014, 11:20 am	#3
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,608	Re: RS "Heavy Duty" Output Transformer Well, that would be a good thing since it looks too small for me to use in my latest project, but I don't see 'my' transformer on that page. I've attached a photo of mine. Attached Thumbnails __________________ Richard Index: recursive loop: see recursive loop

29th May 2014, 6:45 am	#5
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,608	Re: RS "Heavy Duty" Output Transformer Hi, I have that one - it's surprising that the price was so low!! There is a data sheet that was supplied with the RS output transformers showing how to connect the various taps to achieve the different ratios. __________________ Richard Index: recursive loop: see recursive loop

29th May 2014, 6:04 pm	#6
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Re: RS "Heavy Duty" Output Transformer I have a 'pair', from which you may be able to deduce sufficient data! See the attached photos which I hope will be helpful. Your transformer appears to be the same as the upper one in the pictures below. One transformer is an RS "Heavy Duty", the other is an RS "EL84" transformer which, crucially, has the connection data printed on it. I realise that the impedances are different, but the pin-outs may just be the same. The frame is slightly deeper on the Heavy Duty version but to all intents and purposes they look similar in other respects. Phil Attached Thumbnails __________________ Phil Optimist [n]: One who is not in possession of the full facts Last edited by Phil G4SPZ; 29th May 2014 at 6:11 pm. Reason: Extra info added

29th May 2014, 7:03 pm	#7
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,608	Re: RS "Heavy Duty" Output Transformer Thanks Phil. I think I have the same one as your "Heavy Duty" My understanding is that the "EL84" and the "Heavy Duty" are essentially the same 15W transformer, except that the "EL84" has 43% taps on the primary for UL use as described on the label for yours. I will look at mine tomorrow and see if it has different windings to the "EL84" in your picture. __________________ Richard Index: recursive loop: see recursive loop

29th May 2014, 10:20 pm	#8
Steve_Bell Hexode Join Date: Sep 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 474	Re: RS "Heavy Duty" Output Transformer Do these pages give you what you want? http://www.hifiworks.co.uk/images_fu...%20output1.jpg http://www.hifiworks.co.uk/images_fu...%20output2.jpg http://www.hifiworks.co.uk/images_fu...%20output3.jpg http://www.hifiworks.co.uk/images_fu...%20output4.jpg regards, Steve.

30th May 2014, 7:30 am	#9
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,608	Re: RS "Heavy Duty" Output Transformer Perfect! Thank you. __________________ Richard Index: recursive loop: see recursive loop