philco radio 48-

2/15/2007 8:52:17 PMGreg Krull

My old Philco radio sometimes shuts down after it warms up. Is this a matter of replacing all the tubes or what should I do? Greg

2/15/2007 9:14:33 PMDoug Criner

Greg, replacing the tubes won't help, in all liklihood.

What's called for is systematic troubleshooting after it shuts down and with the power still on. Check all voltages, for example.

What model number is this? 48 is the model year.

:My old Philco radio sometimes shuts down after it warms up. Is this a matter of replacing all the tubes or what should I do? Greg

2/16/2007 9:27:55 AMChuck S

:Greg, replacing the tubes won't help, in all liklihood.
:
:What's called for is systematic troubleshooting after it shuts down and with the power still on. Check all voltages, for example.
:
:What model number is this? 48 is the model year.

Doug,

There is also a Model 48 which is a 120-volt D.C. ONLY model from 1932, FYI. Came in table, cathedral and lowboy style cabinets.

Chuck

2/17/2007 10:27:55 AMGreg Krull

::Greg, replacing the tubes won't help, in all liklihood.
::
::What's called for is systematic troubleshooting after it shuts down and with the power still on. Check all voltages, for example.
::
::What model number is this? 48 is the model year.
:
:Doug,

:
:There is also a Model 48 which is a 120-volt D.C. ONLY model from 1932, FYI. Came in table, cathedral and lowboy style cabinets.
:
:Chuck

The model number is 48-468121; I don't believe it's a DC model. I played it for about an hour last night with no problems, first time in a long time. Where would one start troubleshooting?

Greg

2/17/2007 10:50:34 AMplanigan

:::Greg, replacing the tubes won't help, in all liklihood.
:::
:::What's called for is systematic troubleshooting after it shuts down and with the power still on. Check all voltages, for example.
:::
:::What model number is this? 48 is the model year.
::
::Doug,
:
:
::
::There is also a Model 48 which is a 120-volt D.C. ONLY model from 1932, FYI. Came in table, cathedral and lowboy style cabinets.
::
::Chuck
:
:The model number is 48-468121; I don't believe it's a DC model. I played it for about an hour last night with no problems, first time in a long time. Where would one start troubleshooting?
:Greg

Greg, with the symtoms you have its difficult to say where to start. Since the problem appears to be thermal (heat) induced and intermittant its hard to pin point. You could first start by pulling the chassis and visually inspecting all the components but chances are there will be no tell tale signs visible. You could then, while the radio is operating, tap the components with an insulated probe and see if there is any reaction (e.g. set goes dead or noise heard thru speaker. These are very basic tests and,unless you are lucky,they may not reveal the problem. The trouble with the heat induced symtoms is that it can be in any component. If you are getting no sound at all when it fails, that would tend to point to a problem in the power circuit. If there are noises present after the set fails, describe those noises and maybe someone will recognize the problem. You could try the first to and then come back with more information on the symtoms. PL

2/17/2007 10:51:11 AMplanigan

:::Greg, replacing the tubes won't help, in all liklihood.
:::
:::What's called for is systematic troubleshooting after it shuts down and with the power still on. Check all voltages, for example.
:::
:::What model number is this? 48 is the model year.
::
::Doug,
:
:
::
::There is also a Model 48 which is a 120-volt D.C. ONLY model from 1932, FYI. Came in table, cathedral and lowboy style cabinets.
::
::Chuck
:
:The model number is 48-468121; I don't believe it's a DC model. I played it for about an hour last night with no problems, first time in a long time. Where would one start troubleshooting?
:Greg

Greg, with the symtoms you have its difficult to say where to start. Since the problem appears to be thermal (heat) induced and intermittant its hard to pin point. You could first start by pulling the chassis and visually inspecting all the components but chances are there will be no tell tale signs visible. You could then, while the radio is operating, tap the components with an insulated probe and see if there is any reaction (e.g. set goes dead or noise heard thru speaker. These are very basic tests and,unless you are lucky,they may not reveal the problem. The trouble with the heat induced symtoms is that it can be in any component. If you are getting no sound at all when it fails, that would tend to point to a problem in the power circuit. If there are noises present after the set fails, describe those noises and maybe someone will recognize the problem. You could try the first two and then come back with more information on the symtoms. PL

2/17/2007 11:03:58 AMDoug Criner

I don't see your schematic listed on this site. Try to find one that has a similar tube lineup.

If the set acts up only intermittently, then you'll have to wait until it does before you can troubleshoot. First step, after finding a schematic, is to check the voltages at the various points shown on the schematic. If the set is going completely silent, you will probably find out rather quickly that some voltage is going way off base.

If you are unable to find a schematic that is reasonably close, then you can check the plate and filament voltages on each tube while the set is silent.

Working on these old sets can be very dangerous (e.g., >400V may be present at various places). If you are not reasonably experienced with electrical things, it's probably best to let somebody else do it.

:::Greg, replacing the tubes won't help, in all liklihood.
:::
:::What's called for is systematic troubleshooting after it shuts down and with the power still on. Check all voltages, for example.
:::
:::What model number is this? 48 is the model year.
::
::Doug,
:
:
::
::There is also a Model 48 which is a 120-volt D.C. ONLY model from 1932, FYI. Came in table, cathedral and lowboy style cabinets.
::
::Chuck
:
:The model number is 48-468121; I don't believe it's a DC model. I played it for about an hour last night with no problems, first time in a long time. Where would one start troubleshooting?
:
:Greg

2/17/2007 7:39:30 PMGreg Krull

Thanks for all the help. Now I've a place to start looking, but the thing has been working fine so it may be a while before I get a chance to troubleshoot. I am an electrician and at least know how to keep myself safe even if I can't fix it.
Thanks again for all the help, Greg.

I don't see your schematic listed on this site. Try to find one that has a similar tube lineup.
:
:If the set acts up only intermittently, then you'll have to wait until it does before you can troubleshoot. First step, after finding a schematic, is to check the voltages at the various points shown on the schematic. If the set is going completely silent, you will probably find out rather quickly that some voltage is going way off base.
:
:If you are unable to find a schematic that is reasonably close, then you can check the plate and filament voltages on each tube while the set is silent.
:
:Working on these old sets can be very dangerous (e.g., >400V may be present at various places). If you are not reasonably experienced with electrical things, it's probably best to let somebody else do it.
:
:
::::Greg, replacing the tubes won't help, in all liklihood.
::::
::::What's called for is systematic troubleshooting after it shuts down and with the power still on. Check all voltages, for example.
::::
::::What model number is this? 48 is the model year.
:::
:::Doug,
::
::
:::
:::There is also a Model 48 which is a 120-volt D.C. ONLY model from 1932, FYI. Came in table, cathedral and lowboy style cabinets.
:::
:::Chuck
::
::The model number is 48-468121; I don't believe it's a DC model. I played it for about an hour last night with no problems, first time in a long time. Where would one start troubleshooting?
::
::Greg