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#31
08-15-2010, 10:20 PM
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This one looks more like a regular transformer, some DuMonts used the huge Sola transformer.
I have some transformers I pulled out of some RCA's, one is from an 8-t-241 I think the other is a 9-t-240 If someone can cross those to the Stancor numbers or check on the voltages maybe one will work. 
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#32
08-15-2010, 10:43 PM
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770Vct @240ma 5V @ 3A 5V @ 2A 6.3V @9A Stancor P-8152 pretty darn close! jr
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#34
08-16-2010, 09:44 AM
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How about the 10v difference in plate voltage? Very Interested in this, if you guys think it will work! I missed a Stancor P-6315 on eBone by a few days...
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#35
08-16-2010, 11:14 AM
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If you think it'll work you're welcome to it.
Some of the rag wiring coming out of it is a little rough, might need replaced. I can take pictures tonight. I notice it has two 5v windings where yours only has one, I'm guessing it's for the Damper heater. If you don't use that it might make up for the 20ma difference.
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#36
08-16-2010, 11:24 AM
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Are the wires fairly well marked as to what they are? I dont want to blow up my set... I've replaced wires on a tranny before. Bruce McGee
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#37
08-16-2010, 12:34 PM
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By not using the 5V 2A winding you lighten the load by 10 watts... also the 6.3 of the RCA transformer is 9A, while the DuMont is designed for 7.4A, so that winding will not be running at full load, another 10.1 watts lightening of the load.
The additional draw at 770V from .240A to .260A is only 15.4watts, so the transformer could actually run cooler. DuMont tended to over-design, so the actual current draw in the B+ may be somewhat less than 260ma. I would consider adding a couple of plate resistors in the 5U4 plate leads or one resistor in series with the input choke, to drop the extra 10 V. Are the dimensions/bolt patterns similar? jr
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#38
08-16-2010, 02:00 PM
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While you're searching for a new transformer, this is an ideal time to replace all of the electrolytics in the power supply. Or, at least replace that burned-up cap before you power it up again
 Phil
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#39
08-16-2010, 02:04 PM
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My tranny is about 3 3/4" X 3 1/8" more or less. The measurement is mounting bolts center to center.
I have a 6.3v filament tranny rated at 14 amps. I tied it to the filament circuit. Everything except the Hz output, and damper lit up. It was nice to see this. Output and damper lit up when I disconnected one of the primary leads on this fried tranny and applied power to the set. EDIT: I am replacing all electrolytics and many other caps before this set is turned on. Im going to store the cabinet and bring the chassis inside for some work. Another EDIT: Lost my mind and listed both the hz output and the damper as being on the 2nd transformer. Only the damper is on that tranny. Last edited by holmesuser01; 08-16-2010 at 02:58 PM. Reason: The poster is losing his mind, fast!!
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#40
08-16-2010, 02:34 PM
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 My Sams schematic shows that the second power transformer (T-2) is only used to supply heater voltage to the damper diode (6W4) heater, and that the Horizontal output tube (6BG6G) is connected to the "normal" non-isolated heater circuit (from T-1) as all of the other tubes, with one side of the heater circuit grounded. What does the Riders show? jr
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#41
08-16-2010, 02:55 PM
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OOPS!!
My turn for a blunder!!! You are absolutely right. The Hz output is on the regular filament string. I was thinking about the output and damper when I posted that. Dork Me!!!
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#42
08-16-2010, 04:14 PM
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Glad to hear that the set is wired correctly...I was thinking that if the heaters of the damper and horizontal output were, indeed tied together by mistake, that could have contributed to the failure of the transformer... things could have been very exciting if the heater shorted to the cathode on the damper.
BTW, the RCA 9-T-240 used a 5V4G for the damper, hence the extra 5V 2A winding on the RCA transformer. jr
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#43
08-16-2010, 06:35 PM
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I think the RCA transformer is going to be physically larger, I don't have the 9-T with me here at work but I have one from an 8-T and it measures 4 1/8" X 3 1/4".
I'll have to check the 9-T but I think they were the same size. I also have a Motorola TS-9 chassis here and the transformer seems to be pretty close to yours at 3 3/4" X 3 1/8". Electrically I don't know, anyone have specs on that one handy?
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#44
08-16-2010, 07:09 PM
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The 5U4/5Y3 model shows as follows: 730 Vct @ 2.23A !! that can't be right, must be 223 ma?? 460 Vct @ 58ma 5V @ 3A (for 5U4) 5V @ 2A (for 5Y3) 5V @ 2A (for 5V4G damper) 6.3 @ 7A (for most tubes) 6.3 @ 0.6A (for CRT) Stancor P-8157, Chicago TP-450 hope this helps, jr
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#45
08-16-2010, 08:48 PM
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OK, I measured the 9-T transformer and it's 3" X 3 3/4" across the bolt centers.
The wiring is pretty shot and hard to tell one from another but I suppose it'll be easier once the cover is off. It's rusty on top but I see no evidence of overheating. Anyways it's yours for shipping if you want it, I can probably fit it into a Priority Flat Rate box for $10.70. It'll be close on the 5 1/2" side of the box but If I put some nuts on the screws and pad it with stiff cardboard they'll have a tough time damaging this hunk of Iron! Last edited by Eric H; 08-16-2010 at 08:55 PM.
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