1957 Wonderbar Tube/Vibrator part numbers?

[Cadillac Jack 82]

Does anyone have the correct tube/vibrator list for the 1957 Cadillac Wonderbar radio?  Thanks!

Tim

[J. Gomez]

Does anyone have the correct tube/vibrator list for the 1957 Cadillac Wonderbar radio?  Thanks!

Tim

Tim,

FYI

[Cadillac Jack 82]

Thanks I found a vibrator on Ebay.  I just need to identify the tube numbers/types.  Do you have that list?

[J. Gomez]

Thanks I found a vibrator on Ebay.  I just need to identify the tube numbers/types.  Do you have that list?

8 Tubes: 12BA6 12BE6 12BA6 12BF6 12AU7 6V6GT 6V6GT 0Z4

If your is the 725 8065

HTH

[bcroe]

Chances are most if not all the tubes are serviceable; the vibrator and the
0Z4 rectifier are the common failures.  After that think about ancient, leaky
capacitors.  Bruce Roe

[TJ Hopland]

Isn't the OZ4 one of the ones you can get a plug in solid state replacement for?     In the stuff I used to work on the rectifiers hardly ever had issues but my stuff ran on line voltage so the overall power supply design was likely different than mobile stuff.   

[bcroe]

Isn't the OZ4 one of the ones you can get a plug in solid state replacement for?  In the stuff I used to work on the rectifiers hardly ever had issues but my stuff ran on line voltage so the overall power supply design was likely different than mobile stuff. 

Without a heated cathode the 0Z4 simplified the battery rectifier problem,
but it had a shorter life.  A couple silicon diodes can do the same thing, if
chosen for that hostile environment.  Probably someone makes it.  Bruce Roe

[TJ Hopland]

I didn't notice they were cold cathode.  That should make em easier to convert to a diode because you don't have to account for the lack of heater load.  Harsh environment meaning voltages?   That is one nice thing about everything being switchers these days,  plenty of high voltage components available again.   

[bcroe]

I didn't notice they were cold cathode.  That should make em easier to convert to a diode because you don't have to account for the lack of heater load.  Harsh environment meaning voltages?  That is one nice thing about everything being switchers these days, plenty of high voltage components available again. 

From the original tubes with directly heated filament/cathodes, ground
was established as the negative terminal of the circuit.  With AC you
could use a pair of diode tubes for a full wave rectifier, or one tube with
2 plates.  The latter was chosen, but its cathode must be at the positive
plate potential.  So if directly heated, the filament can't be at ground;
this was solved on AC radios by a special (5V) winding on the power
transformer for the rectifier. 

The above was very undesireable when the AC had to be generated
by a limited capacity vibrator.  Some car radios used a 6X5 type of
tube with indirectly heated cathode; these would tolerate full plate
voltage between the filament and cathode.  Another attempt was
the synchronous 6 pin vibrator, using a second set of contacts to
connect the transformer secondary when the correct voltage was
present. 

The 0Z4 solved the problem and reduced the power consumed by
the battery powered radio.  But it had a somewhat shorter life. 

The silicon diode appears to be a drop in replacement.  But
diodes have a specific limited reverse voltage, to avoid destruction. 
The vibrator power supply, like your ignition, has at least the
possibility of generating some extremely high voltage spikes. 
These spikes may be extremely short, tubes tolerate them, but
diodes don't.  To help with this there is the "buffer" cap already
used on the transformer secondary.  If this cap fails, it may take
the diodes with it.  Bruce Roe

[Cadillac Jack 82]

So I've started testing my radio to see what the issue is.  The first thing I did was remove the old fuse that was in the connector.  It turns out some idiot modified the old 7.5 amp fuse with a piece of copper.  When I added a new 7.5 fuse it popped.  I added another and it popped.  I assume that the vibrator is causing the fuses to pop?  Should I just remove the unit and have it rebuilt?

[bcroe]

Start by pulling the vibrator and seeing if the fuse holds.  It would be best
to use an adjustable battery eliminator with meters to check drain.  If the
fuse still blows, something is shorted in the 12V circuitry; should not be
hard to fix.  If the drain drops way back, I'd replace the transformer
secondary buffer cap, put in a replacement vibrator, and try again without
the 0Z4.  If that works but putting in the 0Z4 blows the fuse, you probably
have a short in the 200V B+ circuitry, typically a cap.  Any radio that age
is ready for all new replacement caps anyway, not very expensive if you
supply the labor.  Bruce Roe

[J. Gomez]

So I've started testing my radio to see what the issue is.  The first thing I did was remove the old fuse that was in the connector.  It turns out some idiot modified the old 7.5 amp fuse with a piece of copper.  When I added a new 7.5 fuse it popped.  I added another and it popped.  I assume that the vibrator is causing the fuses to pop?  Should I just remove the unit and have it rebuilt?

Agree with Bruce's comments, the +12V from the fuse is feed to the power transformer to energize the vibrator. If the contacts are welded together (which most are due to arching) it will blow the fuse.

The rest would be up to a specialist to care for if you are not into electronics.   

Good luck..!

[Walter Youshock]

That is not good.  A new solid state vibrator MAY fix it but that and throwing tubes at it is not going to solve the problem of dried out capacitors.