Hello everyone. I just found a small deco console from 1934, is there a more detailed schematic available other than the one on the site? The underside of this chassis has a plate mounted perpendicular to the chassis base that has a bunch of caps that appear to be covered in tar on the ends, and none have any values on them. The electrolytics are easy to see in the can, but none of the others. When I plugged it in, the 42 output tube does not lite at all, despite the filament checking ok on my tester, but not the tube, and the transformer starts to get pretty warm, so I dont leave it plugged in for too long. Do you experts think its worth replacing the electrolytics, perhaps they are shorted? Or do you think the transformer is bad and I cannot repair the set? Any suggestions would be appreciated, thanks again .
Dave

Hi Dave

Here is information on WR-29:

http://www.nostalgiaair.org/PagesByModel/286/M0024286.pdf

Not the easiest to read but parts list is clear.

Don't operate the radio unless you remove the 80 tube. The transformer can be damaged.

If you remove the 80, load on the high voltage transformer winding is removed. The transformer may get a little warm but not hot.

If other tubes are lit so should the 42. Maybe the two large pins don't make contact and need cleaning?

Norm

:Hello everyone. I just found a small deco console from 1934, is there a more detailed schematic available other than the one on the site? The underside of this chassis has a plate mounted perpendicular to the chassis base that has a bunch of caps that appear to be covered in tar on the ends, and none have any values on them. The electrolytics are easy to see in the can, but none of the others. When I plugged it in, the 42 output tube does not lite at all, despite the filament checking ok on my tester, but not the tube, and the transformer starts to get pretty warm, so I dont leave it plugged in for too long. Do you experts think its worth replacing the electrolytics, perhaps they are shorted? Or do you think the transformer is bad and I cannot repair the set? Any suggestions would be appreciated, thanks again .
:Dave

Hi Dave

You asked about replacing electrolytic caps. They always should be replaced in old radios.

You may first want to determine if the transformer is bad. It is one of the most expensive parts to replace.

Norm

:Hi Dave
:
: Here is information on WR-29:
:
:http://www.nostalgiaair.org/PagesByModel/286/M0024286.pdf
:
: Not the easiest to read but parts list is clear.
:
: Don't operate the radio unless you remove the 80 tube. The transformer can be damaged.
:
: If you remove the 80, load on the high voltage transformer winding is removed. The transformer may get a little warm but not hot.
:
: If other tubes are lit so should the 42. Maybe the two large pins don't make contact and need cleaning?
:
:Norm
:
::Hello everyone. I just found a small deco console from 1934, is there a more detailed schematic available other than the one on the site? The underside of this chassis has a plate mounted perpendicular to the chassis base that has a bunch of caps that appear to be covered in tar on the ends, and none have any values on them. The electrolytics are easy to see in the can, but none of the others. When I plugged it in, the 42 output tube does not lite at all, despite the filament checking ok on my tester, but not the tube, and the transformer starts to get pretty warm, so I dont leave it plugged in for too long. Do you experts think its worth replacing the electrolytics, perhaps they are shorted? Or do you think the transformer is bad and I cannot repair the set? Any suggestions would be appreciated, thanks again .
::Dave

Hi Norm, I removed the 80, rectifier, and I can still feel the transformer getting warm and actually hear something sizzling underneath the chassis, so I unplugged it. The 42 filament does not light up at all, it tests bad, but shows a filament light on the tester, which seems odd to me. Could a resistor or cap be shorted and cause these things? I do not want to recap and get a new 42 if the transformer is shot, thanks for all the advice,
Dave

:
: You asked about replacing electrolytic caps. They always should be replaced in old radios.
:
: You may first want to determine if the transformer is bad. It is one of the most expensive parts to replace.
:
:Norm
:
::Hi Dave
::
:: Here is information on WR-29:
::
::http://www.nostalgiaair.org/PagesByModel/286/M0024286.pdf
::
:: Not the easiest to read but parts list is clear.
::
:: Don't operate the radio unless you remove the 80 tube. The transformer can be damaged.
::
:: If you remove the 80, load on the high voltage transformer winding is removed. The transformer may get a little warm but not hot.
::
:: If other tubes are lit so should the 42. Maybe the two large pins don't make contact and need cleaning?
::
::Norm
::
:::Hello everyone. I just found a small deco console from 1934, is there a more detailed schematic available other than the one on the site? The underside of this chassis has a plate mounted perpendicular to the chassis base that has a bunch of caps that appear to be covered in tar on the ends, and none have any values on them. The electrolytics are easy to see in the can, but none of the others. When I plugged it in, the 42 output tube does not lite at all, despite the filament checking ok on my tester, but not the tube, and the transformer starts to get pretty warm, so I dont leave it plugged in for too long. Do you experts think its worth replacing the electrolytics, perhaps they are shorted? Or do you think the transformer is bad and I cannot repair the set? Any suggestions would be appreciated, thanks again .
:::Dave

Hi Dave

Do other tubes light? If not the filament wires may be shorted somewhere under the chassis? If other tubes light there isn't a short in your wiring. Tubes are wired in parallel.

Sizzling sound under the chassis is the power transformer. When the 80 is pulled and a transformer sizzles it bad unless wires under the chassis are shorted. Usually you can smell a transformer burning.

Transformers can be replaced but it takes some work. PTOP, www.oldradioparts.com usually has the best prices on used power transformers.

Norm

:Hi Norm, I removed the 80, rectifier, and I can still feel the transformer getting warm and actually hear something sizzling underneath the chassis, so I unplugged it. The 42 filament does not light up at all, it tests bad, but shows a filament light on the tester, which seems odd to me. Could a resistor or cap be shorted and cause these things? I do not want to recap and get a new 42 if the transformer is shot, thanks for all the advice,
:Dave
:
::
:: You asked about replacing electrolytic caps. They always should be replaced in old radios.
::
:: You may first want to determine if the transformer is bad. It is one of the most expensive parts to replace.
::
::Norm
::
:::Hi Dave
:::
::: Here is information on WR-29:
:::
:::http://www.nostalgiaair.org/PagesByModel/286/M0024286.pdf
:::
::: Not the easiest to read but parts list is clear.
:::
::: Don't operate the radio unless you remove the 80 tube. The transformer can be damaged.
:::
::: If you remove the 80, load on the high voltage transformer winding is removed. The transformer may get a little warm but not hot.
:::
::: If other tubes are lit so should the 42. Maybe the two large pins don't make contact and need cleaning?
:::
:::Norm
:::
::::Hello everyone. I just found a small deco console from 1934, is there a more detailed schematic available other than the one on the site? The underside of this chassis has a plate mounted perpendicular to the chassis base that has a bunch of caps that appear to be covered in tar on the ends, and none have any values on them. The electrolytics are easy to see in the can, but none of the others. When I plugged it in, the 42 output tube does not lite at all, despite the filament checking ok on my tester, but not the tube, and the transformer starts to get pretty warm, so I dont leave it plugged in for too long. Do you experts think its worth replacing the electrolytics, perhaps they are shorted? Or do you think the transformer is bad and I cannot repair the set? Any suggestions would be appreciated, thanks again .
::::Dave

Regarding your #42 tube, try powering it from a 6.3 volt source you know....hopefully one that's adjustable for higher voltages. If the tube overloads the power supply, then it has a short inside. If the base is loose, it is possible that the bulb rotated and shorted out the leads. You would get a good continuity reading, but the tube would not light. If you measured the continuity, it'd be very low in resistance. The tube filament might be a little higher (not much when it is cold). However, if that was the source of your sizzling, I'd think that the wires inside of the tube base would start to sizzle, too, since they are rather thin.

On the other hand, if the tube has a bit of resistance, and isn't shorting out the power supply you are feeding it with, it could have lost its seal. The getter in older tubes doesn't react very quickly, and can stay silver for a very long time, even if there is a lot of air inside of the tube. To see if this is the case, try increasing the voltage to the tube with your power supply. Increase it as much as twice (12.6 volts), and maybe even more, until you start to see it light. If it lights with a higher voltage, but will not light with its rated voltage, then the tube definitely has leaked, and is full of air. Tubes normally contain a vacuum. A vacuum doesn't conduct heat away at all. The only way heat can leave the filament is through radiation and through the traces of air that still remain in the tube (and they are very small). If, on the other hand, the tube is full of air, heat will be drawn away quickly, and the filament won't light under normal voltage. If you manage to get it to light, you will also notice that when you cut power, it goes out very quickly. You may wonder why light bulbs will still light when broken. Well, modern light bulbs don't contain a vacuum, but rather an inert gas. The filament is designed to operate with the heat losses of the gas, and will operate in a similar manner in air (though it will oxidize and burn out).

...Back to your short.....if the 42 filament is not shorted, and is not a source of your sizzle problem, perhaps it is best to pull all tubes and see if the transformer still sizzles. You can also disconnect all of the transformer wires except for the primary wires, and then see if it still sizzles. If not, then you most likely have trouble in the radio wiring, and not in the transformer.

Use the sources Norm recommended for a new transformer, if necessary.

T.

I kind of left out a few details. One is that getter, the silver or dark brown mirror-like substance on the glass, is designed to react with trace amounts of air still left in the tube. The getter absorbs the gasses so that they do not interfere with the tube's operation. Modern getters, usually a dark brown metallic color, react very quickly. If you break a tube, the getter is sure to turn white within a few seconds. Older tubes, however, with their bright silver getter, don't turn white right away. Sometimes the getter can stay silver for years. If the getter is silver, it doesn't necessarily mean that the tube's seal is still good.

T.

:Regarding your #42 tube, try powering it from a 6.3 volt source you know....hopefully one that's adjustable for higher voltages. If the tube overloads the power supply, then it has a short inside. If the base is loose, it is possible that the bulb rotated and shorted out the leads. You would get a good continuity reading, but the tube would not light. If you measured the continuity, it'd be very low in resistance. The tube filament might be a little higher (not much when it is cold). However, if that was the source of your sizzling, I'd think that the wires inside of the tube base would start to sizzle, too, since they are rather thin.
:
:On the other hand, if the tube has a bit of resistance, and isn't shorting out the power supply you are feeding it with, it could have lost its seal. The getter in older tubes doesn't react very quickly, and can stay silver for a very long time, even if there is a lot of air inside of the tube. To see if this is the case, try increasing the voltage to the tube with your power supply. Increase it as much as twice (12.6 volts), and maybe even more, until you start to see it light. If it lights with a higher voltage, but will not light with its rated voltage, then the tube definitely has leaked, and is full of air. Tubes normally contain a vacuum. A vacuum doesn't conduct heat away at all. The only way heat can leave the filament is through radiation and through the traces of air that still remain in the tube (and they are very small). If, on the other hand, the tube is full of air, heat will be drawn away quickly, and the filament won't light under normal voltage. If you manage to get it to light, you will also notice that when you cut power, it goes out very quickly. You may wonder why light bulbs will still light when broken. Well, modern light bulbs don't contain a vacuum, but rather an inert gas. The filament is designed to operate with the heat losses of the gas, and will operate in a similar manner in air (though it will oxidize and burn out).
:
:...Back to your short.....if the 42 filament is not shorted, and is not a source of your sizzle problem, perhaps it is best to pull all tubes and see if the transformer still sizzles. You can also disconnect all of the transformer wires except for the primary wires, and then see if it still sizzles. If not, then you most likely have trouble in the radio wiring, and not in the transformer.
:
:Use the sources Norm recommended for a new transformer, if necessary.
:Tom,

Does it make sense to try another 42 from one of my other radios? I will also pull all the tubes and see if I still get the sizzle. Thanks for the comments, It appears to me the transformer is shot.
Dave
:T.

.....You could also pull a #42 from one of your other radios. Being the anal obsessive compulsive guy that I am, I always like to find the source of my troubles (perhaps the source is being anal, but that's another story)....so if you want to find out why your #42 tube won't light, try lighting it with higher voltages. If it does what I said it might do, then you have a tube with a leak.

T.

Also....I assume that this is Dave Froelich, but since I wasn't sure, I explained how getter works. I'm sure you know how getter works if you're Dave Froelich.

T.