Greetings Lads:
Thordarson T-17S12
This thing has leads I've never seen before.
Out of one side:
#16 Yellow with Brn (?) stripe
#18 Yellow with Brn
Black
Red
Yellow/Red
Yellow/Brn
Out of the other side
#16 Black
#18 Yellow
Yellow
Red
Green
Black
Wires on either side are unrelated DC resistance wise to the other side. There are only two #16 leads?? Unrelated continuity wise. It was advertised as a 4400/4/8/16/250/500/70.7V.
Who has an old Thordarson Catalog. I've tried to download from Bama with no luck.
Dan H
Thordarson OT color codes??
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skyboltone
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Thordarson OT color codes??
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Thordarson OT color codes??
http://www.bunkerofdoom.com/xfm/THORDAR ... on400c.pdf
scroll down to page 8, also will be listed T-17S12
had to look back in the older cat. for that model.
scroll down to page 8, also will be listed T-17S12
had to look back in the older cat. for that model.
Re: Thordarson OT color codes??
I have an old Thordarson Type 8384. I knew it was 45 watts but other than that i didn't know much about it until now.
Thanks for the link Richie!
Thanks for the link Richie!
Re: Thordarson OT color codes??
your welcome.. i think they listed using the RTMA code. So you might be able to look that up on the colors,and what they are for. Some of the other books there,may also have some updates what the colors match up for.
Might look in haldarson or stancor etc.. and see if they used the same color code.and they might list what they are.
The link i posted was just for one year book.. this link has many of the others. One section lists subs and cross references..
http://www.bunkerofdoom.com/xfm/index.html
Might look in haldarson or stancor etc.. and see if they used the same color code.and they might list what they are.
The link i posted was just for one year book.. this link has many of the others. One section lists subs and cross references..
http://www.bunkerofdoom.com/xfm/index.html
Re: Thordarson OT color codes??
Great Thordarson info!
Dan try to copy & paste the catalog listed at BAMA to your desktop, worked for me.I can email it to ya if it still doesn't work..
Dan try to copy & paste the catalog listed at BAMA to your desktop, worked for me.I can email it to ya if it still doesn't work..
Re: Thordarson OT color codes??
I have in PDF a Thordarson cat that lists this item, but there is no info on color codes. It says this is for two 6L6 with 300v on plates and screens, 95mA per side and 25W. It lists secondary at 4-8-16-250-500z, but no 70v, though this might have been available later. This must be a whopping big one! In 1939, it sold for $4.00, which wasn't the most expensive, but a fair bit of change back in the day.
It might be the case that there are two interleaved secondary windings. One for the 4-8-16 and the other for the 250-500 (and maybe the 70v if actually present).
Since the catalog discusses plates & screens, I would begin by assuming there are 40% UL taps on the primary. So, the first thing I'd do is try to identify the primary. The primary winding will have a relatively high DCR, maybe several hundred ohms and the screen taps will be roughly half of that.
For example, maybe DCR on the outer legs of the primary is 500 ohms and the screen taps are 200 ohms. There will also be a CT that would give you roughly 250 ohms on each half of the plate connections and 100 ohms on each half of the screen connection. So, you are looking for a group of 5 wires that make up the primary.
On the secondary, the 4-8-16 part of the winding as well as the 250-500 shold ohm at some very low numbers, maybe 1 ohm or less, maybe a bit more.
Assuming the 4-8-16 is one winding, there is a group of 4 wires, one of which is common and the other three should each increase in DCR as you work you way up the coil. I can't really guess, but let me suggest you are looking for DCR to go from 0.5 to 0.6 to 0.9 or something like that, not sure. For this, I suspect the second group black-green-red-yellow. Then, maybe the black is also common to the 250-500 taps? Ohms should rise somewhat, but not all that much.
This leaves me to suspect all those stripped wires are the primary. It may be necessary to tie two of them together to make the CT. Six is one too many, or else one of these is the 70v tap? No way to be sure without testing.
Start making the chart of what ohms you see on what pairs. Sooner or later things will start to fall into place.
It might be the case that there are two interleaved secondary windings. One for the 4-8-16 and the other for the 250-500 (and maybe the 70v if actually present).
Since the catalog discusses plates & screens, I would begin by assuming there are 40% UL taps on the primary. So, the first thing I'd do is try to identify the primary. The primary winding will have a relatively high DCR, maybe several hundred ohms and the screen taps will be roughly half of that.
For example, maybe DCR on the outer legs of the primary is 500 ohms and the screen taps are 200 ohms. There will also be a CT that would give you roughly 250 ohms on each half of the plate connections and 100 ohms on each half of the screen connection. So, you are looking for a group of 5 wires that make up the primary.
On the secondary, the 4-8-16 part of the winding as well as the 250-500 shold ohm at some very low numbers, maybe 1 ohm or less, maybe a bit more.
Assuming the 4-8-16 is one winding, there is a group of 4 wires, one of which is common and the other three should each increase in DCR as you work you way up the coil. I can't really guess, but let me suggest you are looking for DCR to go from 0.5 to 0.6 to 0.9 or something like that, not sure. For this, I suspect the second group black-green-red-yellow. Then, maybe the black is also common to the 250-500 taps? Ohms should rise somewhat, but not all that much.
This leaves me to suspect all those stripped wires are the primary. It may be necessary to tie two of them together to make the CT. Six is one too many, or else one of these is the 70v tap? No way to be sure without testing.
Start making the chart of what ohms you see on what pairs. Sooner or later things will start to fall into place.
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skyboltone
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Re: Thordarson OT color codes??
Thanks PhilS. That's my conclusion this morning. I've done it before on a Fisher OT (also screwy color code) I was just hoping somebody had a cut sheet hanging around. I could have sworn I'd seen one on the internet somewhere.
Anyway, I mispoke on the 70 volt winding. There is a 10% feedback winding though. Hehe. Why not make it as complicated as possible. I did some initial poking around yesterday and did find the two unrelated windings on the stripey side, so I think you are right about the 250/500 being separate. But what about the dang feedback wire? There are 6 leads out of each side so with a CT, two plates and two screens thats 5. Maybe shield on the extra wire? I hope so, that would get the primary side noodled. The secondary should fall togeather like you've observed with the 10% winding being somewhere between start and 4 ohms? I dunno.
Thanks for the input fellers
Dan
Anyway, I mispoke on the 70 volt winding. There is a 10% feedback winding though. Hehe. Why not make it as complicated as possible. I did some initial poking around yesterday and did find the two unrelated windings on the stripey side, so I think you are right about the 250/500 being separate. But what about the dang feedback wire? There are 6 leads out of each side so with a CT, two plates and two screens thats 5. Maybe shield on the extra wire? I hope so, that would get the primary side noodled. The secondary should fall togeather like you've observed with the 10% winding being somewhere between start and 4 ohms? I dunno.
Thanks for the input fellers
Dan
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Thordarson OT color codes??
Dan,
Once you settle on the primary outer legs, runs a low voltage AC on it and see what comes out the other side. This, of course, tells you the turns ratio, and once you have that, all will be known.
I'd like to know the results!
Phil
Once you settle on the primary outer legs, runs a low voltage AC on it and see what comes out the other side. This, of course, tells you the turns ratio, and once you have that, all will be known.
I'd like to know the results!
Phil
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skyboltone
- Posts: 2287
- Joined: Wed May 10, 2006 7:02 pm
- Location: Sparks, NV, where nowhere looks like home.
Re: Thordarson OT color codes??
Sure thing Phil. I'm going to take a go at the wires with a little isopropyl alcohol too and see if I can't get a better idea of the colors. If the primary side is the non stripy side I believe there will be a red blue and black there. The oddball thing is too that you have one larger wire out of each side. Anyway, I'll keep y'all posted.Phil_S wrote:Dan,
Once you settle on the primary outer legs, runs a low voltage AC on it and see what comes out the other side. This, of course, tells you the turns ratio, and once you have that, all will be known.
I'd like to know the results!
Phil
Dan
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Thordarson OT color codes??
Don't know if you tried this yet or not BUT I looked my type 8384 up in the catalog and there was no color code either. I looked through the "Sound Amplifier guide's" on the site that Richie posted and found a sample schem using my exact tranny with the color code on it.
Anyway you might try looking through the guides for a sample schem like I did although mine is straight forward and i prolly could have figured it out with a meter and a variac!
Anyway you might try looking through the guides for a sample schem like I did although mine is straight forward and i prolly could have figured it out with a meter and a variac!
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skyboltone
- Posts: 2287
- Joined: Wed May 10, 2006 7:02 pm
- Location: Sparks, NV, where nowhere looks like home.
Re: Thordarson OT color codes??
[IMG:717:1024]http://i25.tinypic.com/117wgg2.jpg[/img]
Well, it turns out we were all kinda right and kinda wrong. Turns out the side with the stripy wires was the primary. Those are the screen wires that Thordarson advertises as 10% windings in the catalog. I think I'll just cut them off and insulate. Everything else is really rather un-mysterious once you start looking at resistances and then apply some AC. Like other transformers I've looked at this one seems to measure a little lower than advertised in terms of primary impedance. About 10% as it turns out. Same as a Hammond Organ transformer I had Mercury Magnetics looks at. There must be more to the equation than the common T/R squared X secondary impedance = primary impedance. In any case close enough. I'm going to use transformer with a pair of 7551 beam power tubes. I suppose one could try the screen windings but in my experience the less mess around the power tube sockets in a high gain amp the better.
Dan H
Well, it turns out we were all kinda right and kinda wrong. Turns out the side with the stripy wires was the primary. Those are the screen wires that Thordarson advertises as 10% windings in the catalog. I think I'll just cut them off and insulate. Everything else is really rather un-mysterious once you start looking at resistances and then apply some AC. Like other transformers I've looked at this one seems to measure a little lower than advertised in terms of primary impedance. About 10% as it turns out. Same as a Hammond Organ transformer I had Mercury Magnetics looks at. There must be more to the equation than the common T/R squared X secondary impedance = primary impedance. In any case close enough. I'm going to use transformer with a pair of 7551 beam power tubes. I suppose one could try the screen windings but in my experience the less mess around the power tube sockets in a high gain amp the better.
Dan H
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
-
skyboltone
- Posts: 2287
- Joined: Wed May 10, 2006 7:02 pm
- Location: Sparks, NV, where nowhere looks like home.
Re: Thordarson OT color codes??
I'd appreciate it if you could David. I've tried various things and can't get it to open.v846 wrote:Great Thordarson info!
Dan try to copy & paste the catalog listed at BAMA to your desktop, worked for me.I can email it to ya if it still doesn't work..
Dan
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Thordarson OT color codes??
Dan,
PM sent
PM sent