power transformer & choke coil

6/27/2007 11:40:58 AMJames

I am trying to help a lady restore an old Philco 40-380 radio. The power transformer is bad. I have contacted Hammond about a replacment but without requirments they can't help.
Does anyone have any idea of the voltage and currnet needed for this radio?
Also, the original speaker is missing so I will need to replace the power supply choke that was part of the original speaker.

6/27/2007 12:30:35 PMDoug Criner

James: Can you link us to a schematic for this radio? Or else, give us the tube line-up?

When you say the xfmr is bad, which winding(s)?

The speaker field coil can be replaced with a power resistor if you don't wish to bother with buying a replacement choke.
Doug

:I am trying to help a lady restore an old Philco 40-380 radio. The power transformer is bad. I have contacted Hammond about a replacment but without requirments they can't help.
:Does anyone have any idea of the voltage and currnet needed for this radio?
:Also, the original speaker is missing so I will need to replace the power supply choke that was part of the original speaker.
:

6/28/2007 11:17:41 AMJames

:James: Can you link us to a schematic for this radio? Or else, give us the tube line-up?
:
:When you say the xfmr is bad, which winding(s)?
:
:The speaker field coil can be replaced with a power resistor if you don't wish to bother with buying a replacement choke.
:Doug
:
::I am trying to help a lady restore an old Philco 40-380 radio. The power transformer is bad. I have contacted Hammond about a replacment but without requirments they can't help.
::Does anyone have any idea of the voltage and currnet needed for this radio?
::Also, the original speaker is missing so I will need to replace the power supply choke that was part of the original speaker.
::

Doug

The primary is open in the power transformer. It has had some rework that probably contributed to the failure. If I can locate a transformer and replace the choke with a power resistor I may be able to restore the radio. I restored an old GE a number of years ago and really cherish it now.

I have a pdf file of the schematic but do not see where I can attach it.

6/28/2007 11:20:39 AMJames

If you go to resources on this site the schematic is listed, Philco 42-380.
::I am trying to help a lady restore an old Philco 40-380 radio. The power transformer is bad. I have contacted Hammond about a replacment but without requirments they can't help.
::Does anyone have any idea of the voltage and currnet needed for this radio?
::Also, the original speaker is missing so I will need to replace the power supply choke that was part of the original speaker.
::

6/28/2007 1:10:37 PMLewis Linson

You might can find a schematic of a radio that has about the same tube line up, or at least the same output tubes, and get the requirements for your power transformer from that. I would imagine that the same power and output transformers were used in quite a few of the same models, even tho the cases and other things were different, the designers would use a power transformer at hand rather than pay to have a new one designed. You might also use a resistor and PM speaker until you get the rest of the radio working, and then go with a PM speaker and a choke, or try to find an original speaker. Just be sure that the output transformer is on the chassis, speakers do not like to be connected directly to tupe plates.
Lewis

Lewis

6/28/2007 2:05:01 PMNorm Leal

Here is the schematic:

http://www.nostalgiaair.org/PagesByModel/533/M0013533.pdf

This radio only use 6 volts for filaments. It doesn't need a 5 volt winding. A replacement transformer may have a 5 volt winding which can be taped off.

I would look for a transformer with 90 ma high voltage winding. Wouldn't need quite this amount but the radio has push-pull output.

Add up filament currents of tubes and lamps to determine 6 volt winding rating.

Norm

::I am trying to help a lady restore an old Philco 40-380 radio. The power transformer is bad. I have contacted Hammond about a replacment but without requirments they can't help.
::Does anyone have any idea of the voltage and currnet needed for this radio?
::Also, the original speaker is missing so I will need to replace the power supply choke that was part of the original speaker.
:
:You might can find a schematic of a radio that has about the same tube line up, or at least the same output tubes, and get the requirements for your power transformer from that. I would imagine that the same power and output transformers were used in quite a few of the same models, even tho the cases and other things were different, the designers would use a power transformer at hand rather than pay to have a new one designed. You might also use a resistor and PM speaker until you get the rest of the radio working, and then go with a PM speaker and a choke, or try to find an original speaker. Just be sure that the output transformer is on the chassis, speakers do not like to be connected directly to tupe plates.
:Lewis
:
:Lewis
:
:
::

6/29/2007 9:43:16 AMJames

I have some old tube manuals and will look up the tube requirments. Would you have any idea of the voltage drop across the rectifier tube? The schematic shows 195V to the input of the filter capacitor. Thiw would help in determining the transformer secondary voltage.

:
: Here is the schematic:
:
:http://www.nostalgiaair.org/PagesByModel/533/M0013533.pdf
:
: This radio only use 6 volts for filaments. It doesn't need a 5 volt winding. A replacement transformer may have a 5 volt winding which can be taped off.
:
: I would look for a transformer with 90 ma high voltage winding. Wouldn't need quite this amount but the radio has push-pull output.
:
: Add up filament currents of tubes and lamps to determine 6 volt winding rating.
:
:Norm
:
:::I am trying to help a lady restore an old Philco 40-380 radio. The power transformer is bad. I have contacted Hammond about a replacment but without requirments they can't help.
:::Does anyone have any idea of the voltage and currnet needed for this radio?
:::Also, the original speaker is missing so I will need to replace the power supply choke that was part of the original speaker.
::
::You might can find a schematic of a radio that has about the same tube line up, or at least the same output tubes, and get the requirements for your power transformer from that. I would imagine that the same power and output transformers were used in quite a few of the same models, even tho the cases and other things were different, the designers would use a power transformer at hand rather than pay to have a new one designed. You might also use a resistor and PM speaker until you get the rest of the radio working, and then go with a PM speaker and a choke, or try to find an original speaker. Just be sure that the output transformer is on the chassis, speakers do not like to be connected directly to tupe plates.
::Lewis
::
::Lewis
::
::
:::