I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.
The primary winding for the AC line is usually rated 115 volts.
You will need two secondary windings. 6.3 volts @ 2.75 amps or greater for filaments and 230 volts each side of center tap for high voltage. Use a transformer with 70 ma or more for high voltage winding. Check Play Things Of Past for replacement.
http://www.oldradioparts.com/2a23efl.txt
Be sure the replacements fits on your radio chassis.
Norm
:Hello,
:
:I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.
I cannot, after months of looking, find an exact replacement for this transformer. I was wondering what the general opinion is of putting a power resistor in line with the HV windings. If I could find a transformer with a 255-0-255 HV winding, for example, I could put a 220 ohm resistor of 5 or 10 W in line and drop the voltage to around 230V. Is this a good/bad idea? Is there a limit as to what the maximum voltage one could drop safely using a resistor? Any help on this one would be appreciated.
Thanks,
Nicholas
:Hi Nick
:
:The primary winding for the AC line is usually rated 115 volts.
:
:You will need two secondary windings. 6.3 volts @ 2.75 amps or greater for filaments and 230 volts each side of center tap for high voltage. Use a transformer with 70 ma or more for high voltage winding. Check Play Things Of Past for replacement.
:
:http://www.oldradioparts.com/2a23efl.txt
:
:Be sure the replacements fits on your radio chassis.
:
:Norm
:
::Hello,
::
::I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.
Rich
:Hello,
:
:I cannot, after months of looking, find an exact replacement for this transformer. I was wondering what the general opinion is of putting a power resistor in line with the HV windings. If I could find a transformer with a 255-0-255 HV winding, for example, I could put a 220 ohm resistor of 5 or 10 W in line and drop the voltage to around 230V. Is this a good/bad idea? Is there a limit as to what the maximum voltage one could drop safely using a resistor? Any help on this one would be appreciated.
:
:Thanks,
:
:Nicholas
:
::Hi Nick
::
::The primary winding for the AC line is usually rated 115 volts.
::
::You will need two secondary windings. 6.3 volts @ 2.75 amps or greater for filaments and 230 volts each side of center tap for high voltage. Use a transformer with 70 ma or more for high voltage winding. Check Play Things Of Past for replacement.
::
::http://www.oldradioparts.com/2a23efl.txt
::
::Be sure the replacements fits on your radio chassis.
::
::Norm
::
:::Hello,
:::
:::I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.
If the high voltage was an actual measurement, and one winding was shorted, the measured voltage would be lower than it should be. If the voltage is off of a schematic, it is measured with load, and is at points indicated- if after filter network, the transformer voltage is actually slightly lower, as the filter network raises circuit voltages somewhat higher than AC RMS voltages. (It just means the filter raises the measurable voltage at the expense of a little current.)
What that means is, if you found a transformer with a slightly lower high voltage, say 200-0-200 volts, that would still work if you had 70 to 75 milliamps available. Your circuit voltages would then be different fromt he schematic, but the radio would still work.
Also too, if the tube maximum values are 300 to 350 volts on the plate (peak) of the output tubes, you may not need the dropping resistor at all, as your open circuit voltage is going to be higher than the loaded circuit voltage, so you should be able to use a 250-0-250 safely. If you did need to add resistance, the only area of real concern would be the supply to the audio output transformer (Output tube(s) B+), rather than the whole B supply string in most cases.
:You could drop the required 30 volts by putting a resistor in series with the DC output...sounds like 10W would be good. Another thought is to put some inductance in series with the primary. Maybe something like the secondary of a filament transformer. The goal would be to drop the primary voltage on the power transfomer by about 10%. This method would also generate less wasted heat.
:
:Rich
:
:
::Hello,
::
::I cannot, after months of looking, find an exact replacement for this transformer. I was wondering what the general opinion is of putting a power resistor in line with the HV windings. If I could find a transformer with a 255-0-255 HV winding, for example, I could put a 220 ohm resistor of 5 or 10 W in line and drop the voltage to around 230V. Is this a good/bad idea? Is there a limit as to what the maximum voltage one could drop safely using a resistor? Any help on this one would be appreciated.
::
::Thanks,
::
::Nicholas
::
:::Hi Nick
:::
:::The primary winding for the AC line is usually rated 115 volts.
:::
:::You will need two secondary windings. 6.3 volts @ 2.75 amps or greater for filaments and 230 volts each side of center tap for high voltage. Use a transformer with 70 ma or more for high voltage winding. Check Play Things Of Past for replacement.
:::
:::http://www.oldradioparts.com/2a23efl.txt
:::
:::Be sure the replacements fits on your radio chassis.
:::
:::Norm
:::
::::Hello,
::::
::::I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.
If the high voltage was an actual measurement, and one winding was shorted, the measured voltage would be lower than it should be. If the voltage is off of a schematic, it is measured with load, and is at points indicated- if after filter network, the transformer voltage is actually slightly lower, as the filter network raises circuit voltages somewhat higher than AC RMS voltages. (It just means the filter raises the measurable voltage at the expense of a little current.)
What that means is, if you found a transformer with a slightly lower high voltage, say 200-0-200 volts, that would still work if you had 70 to 75 milliamps available. Your circuit voltages would then be different fromt he schematic, but the radio would still work.
Also too, if the tube maximum values are 300 to 350 volts on the plate (peak) of the output tubes, you may not need the dropping resistor at all, as your open circuit voltage is going to be higher than the loaded circuit voltage, so you should be able to use a 250-0-250 safely. If you did need to add resistance, the only area of real concern would be the supply to the audio output transformer (Output tube(s) B+), rather than the whole B supply string in most cases.
:You could drop the required 30 volts by putting a resistor in series with the DC output...sounds like 10W would be good. Another thought is to put some inductance in series with the primary. Maybe something like the secondary of a filament transformer. The goal would be to drop the primary voltage on the power transfomer by about 10%. This method would also generate less wasted heat.
:
:Rich
:
:
::Hello,
::
::I cannot, after months of looking, find an exact replacement for this transformer. I was wondering what the general opinion is of putting a power resistor in line with the HV windings. If I could find a transformer with a 255-0-255 HV winding, for example, I could put a 220 ohm resistor of 5 or 10 W in line and drop the voltage to around 230V. Is this a good/bad idea? Is there a limit as to what the maximum voltage one could drop safely using a resistor? Any help on this one would be appreciated.
::
::Thanks,
::
::Nicholas
::
:::Hi Nick
:::
:::The primary winding for the AC line is usually rated 115 volts.
:::
:::You will need two secondary windings. 6.3 volts @ 2.75 amps or greater for filaments and 230 volts each side of center tap for high voltage. Use a transformer with 70 ma or more for high voltage winding. Check Play Things Of Past for replacement.
:::
:::http://www.oldradioparts.com/2a23efl.txt
:::
:::Be sure the replacements fits on your radio chassis.
:::
:::Norm
:::
::::Hello,
::::
::::I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.
You might try contacting the following:
Heybor Transformer
17382 Hayes Street
Grand Haarbor, MI 49417
(616) 842-5830
If you have your old transformer, they can make you a new one with the same rating, size and appearance. I have not dealt with them personally, but know other restorers who have. But of course you need to verify the required rating for that HV secondary voltage, as John has mentioned.
Poston
:Hello,
:
:I cannot, after months of looking, find an exact replacement for this transformer. I was wondering what the general opinion is of putting a power resistor in line with the HV windings. If I could find a transformer with a 255-0-255 HV winding, for example, I could put a 220 ohm resistor of 5 or 10 W in line and drop the voltage to around 230V. Is this a good/bad idea? Is there a limit as to what the maximum voltage one could drop safely using a resistor? Any help on this one would be appreciated.
:
:Thanks,
:
:Nicholas
:
::Hi Nick
::
::The primary winding for the AC line is usually rated 115 volts.
::
::You will need two secondary windings. 6.3 volts @ 2.75 amps or greater for filaments and 230 volts each side of center tap for high voltage. Use a transformer with 70 ma or more for high voltage winding. Check Play Things Of Past for replacement.
::
::http://www.oldradioparts.com/2a23efl.txt
::
::Be sure the replacements fits on your radio chassis.
::
::Norm
::
:::Hello,
:::
:::I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.
A transformer can be wound like Poston mentions.
We are overlooking something, the schematic. This radio uses a standard circuit with 6F6 output tube. You could use a higher voltage secondary (250 volts) transformer without a problem as long as it fits on the chassis.
B+ voltage will be a little higher but not a problem as long as you don't exceed capacitor ratings. If you want lower voltage a wire wound resistor could be added.
Norm
:Hi Nicholas,
:
:You might try contacting the following:
:Heybor Transformer
:17382 Hayes Street
:Grand Haarbor, MI 49417
:(616) 842-5830
:
:If you have your old transformer, they can make you a new one with the same rating, size and appearance. I have not dealt with them personally, but know other restorers who have. But of course you need to verify the required rating for that HV secondary voltage, as John has mentioned.
:
:Poston
:
:
::Hello,
::
::I cannot, after months of looking, find an exact replacement for this transformer. I was wondering what the general opinion is of putting a power resistor in line with the HV windings. If I could find a transformer with a 255-0-255 HV winding, for example, I could put a 220 ohm resistor of 5 or 10 W in line and drop the voltage to around 230V. Is this a good/bad idea? Is there a limit as to what the maximum voltage one could drop safely using a resistor? Any help on this one would be appreciated.
::
::Thanks,
::
::Nicholas
::
:::Hi Nick
:::
:::The primary winding for the AC line is usually rated 115 volts.
:::
:::You will need two secondary windings. 6.3 volts @ 2.75 amps or greater for filaments and 230 volts each side of center tap for high voltage. Use a transformer with 70 ma or more for high voltage winding. Check Play Things Of Past for replacement.
:::
:::http://www.oldradioparts.com/2a23efl.txt
:::
:::Be sure the replacements fits on your radio chassis.
:::
:::Norm
:::
::::Hello,
::::
::::I guess I am relatively new to replacing faulty transformers in radios. I have a 1936 Silvertone 1914 (Riders Page 6-45) with a faulty power transformer. Can anyone give me the specifications I would need to look this transformer up to find a compatible replacement? Looking at the schematic, I see what I believe to be a 117V primary, a 230V secondary and a 6V filament winding, but is there anything else I am missing? As I said, transformer replacement is new to me and slightly confusing. Any help would be greatly appreciated.