Hi!

There is no audio output at all, not even the usual hum.

You might wish to check the speaker system and its wiring. Sometimes
the voice coil in a speaker opens up, either because of abuse or
normal wear and tear.

If the speakers in this set are a conventional permanent magnet type,
you can disconnect the leads from them and use either an ohmmeter on
the resistance range OR a nine volt battery across the contacts of
each speaker. Clicking sounds or static from the speaker when you
connect the meter or battery indicate that it is good. Don't leave the
meter or battery connected for very long, or you may open the voice
coil.

This one does not have a power transformer in it at
all.

This is a so-called "line connected" or "series string" set. The tubes
are wired in series so their heater voltages will all add up to
roughly 110/120 volts. If the number of tubes and their voltages don't
add up to line voltage, then a large resistor may be used to drop the
voltage to the point where it is needed.

You might look into replacing this resistor (if your set has one) with
something more modern, such as a diode. This will make the set run
cooler and more efficiently.

Be VERY careful when working on this chassis under power. Better yet--
don't have the set on or plugged in when you're working on it. There
is absolutely no isolation from the power line and you could really
hurt or kill yourself by doing the wrong thing. If you want to test
the set while it is apart, plug it in, make sure the (hopefully
nonconductive) knobs are on, conduct your tests and then unplug the
set when you are done.

but 1 of the 50EH5 shows as gaseous and shorted.

Give this tube a visual inspection. You may be able to see the
"getter' inside it. This should normally be a silver color. If it has
turned milky white (or *maybe* red), the tube's vacuum is gone.

I love working on this old stuff, but I need some guidance
here. I figured that if 1 of the tubes is bad, the other
channel should be ok.

Maybe. It depends upon how the unit is designed. Chances are most of
the tubes are good. You will find the most problems with supporting
components, such as capacitors and resistors. The capacitors may be
left alone if they work, but for reliability (and possibly safety)
reasons you should replace them if it all possible. You should also
give thought to reworking the power system if it turns out that the
radio does in fact use a dropping resistor.

For more information, you might also try posting to:
rec.antiques.radio+phono

William

On May 16, 9:36 am, wrote:
Hi!

There is no audio output at all, not even the usual hum.

You might wish to check the speaker system and its wiring. Sometimes
the voice coil in a speaker opens up, either because of abuse or
normal wear and tear.

If the speakers in this set are a conventional permanent magnet type,
you can disconnect the leads from them and use either an ohmmeter on
the resistance range OR a nine volt battery across the contacts of
each speaker. Clicking sounds or static from the speaker when you
connect the meter or battery indicate that it is good. Don't leave the
meter or battery connected for very long, or you may open the voice
coil.

This one does not have a power transformer in it at
all.

This is a so-called "line connected" or "series string" set. The tubes
are wired in series so their heater voltages will all add up to
roughly 110/120 volts. If the number of tubes and their voltages don't
add up to line voltage, then a large resistor may be used to drop the
voltage to the point where it is needed.

You might look into replacing this resistor (if your set has one) with
something more modern, such as a diode. This will make the set run
cooler and more efficiently.

Be VERY careful when working on this chassis under power. Better yet--
don't have the set on or plugged in when you're working on it. There
is absolutely no isolation from the power line and you could really
hurt or kill yourself by doing the wrong thing. If you want to test
the set while it is apart, plug it in, make sure the (hopefully
nonconductive) knobs are on, conduct your tests and then unplug the
set when you are done.

but 1 of the 50EH5 shows as gaseous and shorted.

Give this tube a visual inspection. You may be able to see the
"getter' inside it. This should normally be a silver color. If it has
turned milky white (or *maybe* red), the tube's vacuum is gone.

I love working on this old stuff, but I need some guidance
here. I figured that if 1 of the tubes is bad, the other
channel should be ok.

Maybe. It depends upon how the unit is designed. Chances are most of
the tubes are good. You will find the most problems with supporting
components, such as capacitors and resistors. The capacitors may be
left alone if they work, but for reliability (and possibly safety)
reasons you should replace them if it all possible. You should also
give thought to reworking the power system if it turns out that the
radio does in fact use a dropping resistor.

For more information, you might also try posting to:
rec.antiques.radio+phono

William

Several of the previous posters ignored the fact that the original
poster stated that when one of the tubes was removed, the other
filaments stayed lit This is not quite as simple as they believe.

H. R. Hofmann

"hr(bob) " wrote in message
oups.com...

Several of the previous posters ignored the fact that the original
poster stated that when one of the tubes was removed, the other
filaments stayed lit This is not quite as simple as they believe.

H. R. Hofmann


In your first reply post you mentioned that there could be 2 parallel heater
strings
connected to the AC line, which could be true....
that fact was not ignored but may be irrelevant..... even if one of the
tubes are bad,
some kind of hum or noise should be heard out of the other channel. The
best bet is
probably a B+ problem or open speakers??