Hi.
I have a large amplifier, as was broadly described in the thread title.
It uses a Quad or Octet of these Eriswan 1550, which I'm guessing are Triodes.
They have four 'pins' on the base and the cap is the 5th terminal. Pins isn't such a good term, these things are at least 5/8"....
There is an original schematic here somewhere, looking like an ancient treasure map.
You could take these valves to Oktoberfest!
The Amplifier uses Mercury Arc Rectifiers, which I think are probably mostly dead. So I'm on the lookout for some, anyone have any leads?
Ill take a photograph of them If I get them time to do the fine surgery
I have a large amplifier, as was broadly described in the thread title.
It uses a Quad or Octet of these Eriswan 1550, which I'm guessing are Triodes.
They have four 'pins' on the base and the cap is the 5th terminal. Pins isn't such a good term, these things are at least 5/8"....
There is an original schematic here somewhere, looking like an ancient treasure map.
You could take these valves to Oktoberfest!
An externally hosted image should be here but it was not working when we last tested it.
The Amplifier uses Mercury Arc Rectifiers, which I think are probably mostly dead. So I'm on the lookout for some, anyone have any leads?
Ill take a photograph of them If I get them time to do the fine surgery
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You need to post the number off the rectifiers.
They are probably Mercury Vapor Rectifiers which is the more common nomenclature. The mercury vaporizes and becomes a gas which becomes ionized in the rectification process. The spectural lines for mercury include UV and are best not watched up close.
They may be something like 872 or GL-872.
That is a honker of a tube.
It most likely runs 1KV - 2KV on the plate (anode) so plan on being very careful.
They are probably Mercury Vapor Rectifiers which is the more common nomenclature. The mercury vaporizes and becomes a gas which becomes ionized in the rectification process. The spectural lines for mercury include UV and are best not watched up close.
They may be something like 872 or GL-872.
That is a honker of a tube.
It most likely runs 1KV - 2KV on the plate (anode) so plan on being very careful.
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I don't wish a semantic debate, however my colleague informs me that here during the mid 20th (a little before his time even) we used to test industrial thermionic rectifiers, using our patented device/method.
The test rig was known as the MAR rig, for obvious reasons.
company was at that time BTH, who along with Westinghouse produced and developed Tesla synchronous machines shortly after their invention, just before the turn of the century.
The test rig was known as the MAR rig, for obvious reasons.
company was at that time BTH, who along with Westinghouse produced and developed Tesla synchronous machines shortly after their invention, just before the turn of the century.
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The 2 pint Oktoberfest bottles are marked as Eriswan 1550 if that means anything ��
Edit: oh the valve dates to 1929! Missed that om first glance
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I believe the number on the tube is 1505 rather than 1550.
Type V1505 (aka 14D13) is on display at the National Valve Museum:
http://www.r-type.org/exhib/aaa1098.htm
I believe that's your tube ...
there's also a data sheet:
http://www.r-type.org/pdfs/v1505.pdf
Type V1505 was first introduced in 1961.
radiomuseum.org has some information about Ediswan (Brand) , too:
Name: Edison Swan Electric Co.Ltd.; GB (GB)
Abbreviation: ediswan
Products: Tube manufacturer Model types
Summary:
Edison Swan Electric Company Ltd.; 155 Charing Corsss Road, London W.C.5: Founded 1893 / 1916. One of the first valve makers in GB (The Untited Kingdom). Brands: Ediswan, Mazda (there is another brand Mazda in France which is not of Edison-Swan.
B.T.H. acquired Ediswan in 1928-1929 and Ediswan offered no new models after that but continued the Power Pentode receiver until 1932.
Type V1505 (aka 14D13) is on display at the National Valve Museum:
http://www.r-type.org/exhib/aaa1098.htm
I believe that's your tube ...
there's also a data sheet:
http://www.r-type.org/pdfs/v1505.pdf
Type V1505 was first introduced in 1961.
radiomuseum.org has some information about Ediswan (Brand) , too:
Name: Edison Swan Electric Co.Ltd.; GB (GB)
Abbreviation: ediswan
Products: Tube manufacturer Model types
Summary:
Edison Swan Electric Company Ltd.; 155 Charing Corsss Road, London W.C.5: Founded 1893 / 1916. One of the first valve makers in GB (The Untited Kingdom). Brands: Ediswan, Mazda (there is another brand Mazda in France which is not of Edison-Swan.
B.T.H. acquired Ediswan in 1928-1929 and Ediswan offered no new models after that but continued the Power Pentode receiver until 1932.
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concerning the rectifiers:
could it be Mullard Type RG1/240A, rather than RC1 ?
http://www.r-type.org/exhib/aad0267.htm
data-sheet:
http://www.r-type.org/pdfs/rg1-240a.pdf
somebody from the UK tried to sell these on the bay for GBP 10,-but got no customer interest in August:
http://www.ebay.com/itm/RG1-240A-Me...-New-Old-Stock-Made-by-Mullard-/251326338160?
could it be Mullard Type RG1/240A, rather than RC1 ?
http://www.r-type.org/exhib/aad0267.htm
data-sheet:
http://www.r-type.org/pdfs/rg1-240a.pdf
somebody from the UK tried to sell these on the bay for GBP 10,-but got no customer interest in August:
http://www.ebay.com/itm/RG1-240A-Me...-New-Old-Stock-Made-by-Mullard-/251326338160?
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Ill try and get some photos today and post them over the weekend. We actually have quite a number of the Ediswan valves, to the best of my knowledge it is just the rectifiers that are shot. I did toy with the idea of a class A amp with a single 1505....
The cabinet is over 6 feet tall and about 18" square, and looks to be cast iron. So at least a small army would be required to move it!
Thanks for the interest folks ��
The cabinet is over 6 feet tall and about 18" square, and looks to be cast iron. So at least a small army would be required to move it!
Thanks for the interest folks ��
You could always convert it to solid state rectifiers. Or if you really want to use mercury just source some of the more common types. I know here in the usa it was the 872A. They can handle 1.25 amps steady state. And something like 10kv.
Im sure theres a European equivalent. What socket do the rectifiers use, are they tungar sockets?
Im sure theres a European equivalent. What socket do the rectifiers use, are they tungar sockets?
As far as i am aware diodes wont take the voltage. Unless an uber high current cap multiplier circuit.....
Id ditch the MARs quick as a flash (du-dum) IF i knew a way around the problem
I also have some more photos to upload during a spare minute,perhaps later today. To correct myself the amp runs two v1505 in push pull with current output up to 500mA on the plates. Variable taps for output voltage control. The set was used for interturn insulation testing of rotors on electrical machinery.
Id ditch the MARs quick as a flash (du-dum) IF i knew a way around the problem
I also have some more photos to upload during a spare minute,perhaps later today. To correct myself the amp runs two v1505 in push pull with current output up to 500mA on the plates. Variable taps for output voltage control. The set was used for interturn insulation testing of rotors on electrical machinery.
You need to connect them in series and put a cap and resistor across them to equalize them. You can also use mov's for this too. Or you can buy a pre made hv rectifier array. You can find them on ebay.
I worked on klystron amplifiers that used a b+ of 27kvdc. No vacuum tubes in those supplies just a whole of 5 amp 1kv fast recovery diodes. 3 phase delta secondary meant 6 banks. I think there was over 500 diodes. But there was redundancy in the design since it was in a big oil tank. So it was an ordeal changing them. If you go solid state you'll gain a little more b+. Also you'll need a beam on delay if the amp doesn't already have one.
Outside of boutique audio vacuum rectifiers don't see much use any more, if any.
You will also rid yourself of a big internal heat source too. Was this amp used for a shaker table?
Nick
I worked on klystron amplifiers that used a b+ of 27kvdc. No vacuum tubes in those supplies just a whole of 5 amp 1kv fast recovery diodes. 3 phase delta secondary meant 6 banks. I think there was over 500 diodes. But there was redundancy in the design since it was in a big oil tank. So it was an ordeal changing them. If you go solid state you'll gain a little more b+. Also you'll need a beam on delay if the amp doesn't already have one.
Outside of boutique audio vacuum rectifiers don't see much use any more, if any.
You will also rid yourself of a big internal heat source too. Was this amp used for a shaker table?
Nick
Here is a link to another 1000W amp with a circuit diagram.
It has only two output triodes and they are huge.
A 1kW Audio Amplifier
It has only two output triodes and they are huge.
A 1kW Audio Amplifier
Wow nice! Those Mullard look at least very similar envelope size and base etc. They look like they take a bit more bias and dissipation current than the ediswan,
A class a or whatever you can build with a single tube would be interesting...biased for far less than rated....i mean the filament alone would make a nice lamp...
A class a or whatever you can build with a single tube would be interesting...biased for far less than rated....i mean the filament alone would make a nice lamp...
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