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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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17th Mar 2006, 10:39 pm | #1 |
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Mains Transformer ( For Marconiphone RG81 )
Does anyone have a Transformer suitable for the above.
I estimate that it needs to have secondaries rated at approx. 240vac@150mA, & 6.3vac@3A. The valve lineup is ECC81, ECH81, EBF89, EB91, ECC83, & Two EL84, with Two 6.3v 0.3A pilot lamps. Rectification is by full wave Bridge, the original rectifier, a contact cooled metal(selenium) type B250C75. The Transformer mounts inside the wooden cabinet, and is connected to the PCB via flying leads, so the dimensions and type of construction will not be critical. Please give an idea of price, including postage & packing. Last edited by Paul Stenning; 17th Mar 2006 at 11:51 pm. Reason: Removed unnecessary large bold font |
19th Mar 2006, 8:24 pm | #2 |
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Re: Mains Transformer For Marconiphone Rg81
Hi, You can possibly buy an RS transformer kit. This will already have the primary wound, you would need to add the secondaries then insert the laminations. These items can be useful for jobs like yours.
Best regards, Ed |
22nd Mar 2006, 1:07 pm | #3 |
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Re: Mains Transformer For Marconiphone Rg81
Hi, Ed.,
Hadn.t thought of transformer kits, but, despite working in Radio for many years, do not have an account with RS, and, as far as I know they will only supply to account holders. Will check out their website, though, and possibly CPC's. Thanks for suggestion Regards from Mike (Livewire) |
22nd Mar 2006, 2:48 pm | #4 | |
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Re: Mains Transformer For Marconiphone Rg81
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22nd Mar 2006, 4:25 pm | #5 |
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Re: Mains Transformer For Marconiphone Rg81
I'm not sure whether R S still do power transformer kits. I can only find ferrite core kits in their latest cat. I've used the kits before and found them a bit of a faff to get right. The one I have at the moment runs very hot and is noisy, but of course that's probably down to me! I wouldn't like to attempt a high voltage secondary on one, without using sophisticated winding techniques. (I hand wound mine) It's a shame R S discontinued their valve power transformer, which was very useful. I bought about three or four of these.
Biggles. |
22nd Mar 2006, 4:59 pm | #6 |
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Re: Mains Transformer For Marconiphone Rg81
RS Components still supply a range of transformer kits.
http://rswww.com/cgi-bin/bv/initSess...76715&store=uk
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22nd Mar 2006, 6:08 pm | #7 |
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Re: Mains Transformer For Marconiphone Rg81
That's good news. I suspected that they had discontinued these, it's a few years since I bought one. They are very useful for those awkward "custom" units where you end up only using half the windings or power available after buying off the shelf. I made a 90V+1.5V power supply from one of these but I ended up nearly running out of room, probably because of my winding technique. I dare say that if you start with a large core you may be ok, but as I said before I don't think I'd be confident to wind say a 300-0-300V HT secondary.
Biggles. |
23rd Mar 2006, 12:20 pm | #8 |
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Re: Mains Transformer For Marconiphone Rg81
Hi,to 'Biggles' and G4ILN
Thanks to both for the info. about RS. I haven't yet had time to check out their site, or that of CPC, but will do so. I would agree with you, 'Biggles', in that I would be a bit apprehensive about winding an HT Secondary by hand. I do have somewhere an old copy of 'Coil Design and Construction', one of those Bernard-Babani Booklets, which gives data neccesary, but....! |