1959 Wonderbar Radio Wiring

[Paul]

Hello! I have an awesome 1959 Cadillac CDV, but the original Wonderbar Radio isn't quite working. If it turn it on, I hear a slight 'thump', which I understand is correct, but the volume is very, very low; almost inaudible. I'd like to check the resistors, capacitors, etc., but I can't find a wiring diagram and a list of components. Can any of you very knowledgeable Caddy lovers help me out? Could you direct me to schematics or give a thought on why the volume is so low? Seems the wonder bar function is sticky as well. Antenna works, needs grease I think. Only other odd thing is that the foot switch blows the radio fuse every time I push it, (meaning I only pushed it once!) Assume that's a crossed wire?
Thanks for your help. I'm new here, but love the info!

[J. Gomez]

Hello! I have an awesome 1959 Cadillac CDV, but the original Wonderbar Radio isn't quite working. If it turn it on, I hear a slight 'thump', which I understand is correct, but the volume is very, very low; almost inaudible. I'd like to check the resistors, capacitors, etc., but I can't find a wiring diagram and a list of components. Can any of you very knowledgeable Caddy lovers help me out? Could you direct me to schematics or give a thought on why the volume is so low? Seems the wonder bar function is sticky as well. Antenna works, needs grease I think. Only other odd thing is that the foot switch blows the radio fuse every time I push it, (meaning I only pushed it once!) Assume that's a crossed wire?
Thanks for your help. I'm new here, but love the info!

If yours is the Delco 7272505 you can purchase the complete manual from Photofacts -> https://www.samswebsite.com/photofacts.html these include the schematic, components layout, adjustment, etc. If you are just looking for the schematic I have a copy that I could share.

In your particular case with the loud popping noise at the speaker it maybe the output transistor is bad and would need to be replace. Make sure you do not leave it on for long or turning it on/off as you can damage the speaker(s).

[Paul]

Thanks for the help. I requested the manual where you suggested. If you don't mind sharing the schematic, that would get me a step ahead of the game. Thanks again!

[Gabe Davis]

Hi Paul, check your private messages.

I too have a '59. I got started a few years ago working on my radio but never got a chance to finish it. I did a little research and I think my has a bad output transformer - apparently the germanium transistors in the output stage line to go bad.

I need to get back on the radio fix some day!

[J. Gomez]

Thanks for the help. I requested the manual where you suggested. If you don't mind sharing the schematic, that would get me a step ahead of the game. Thanks again!

Paul,

Shoot me your email via a PM.

Thanks,

[J. Gomez]

Hi Paul, check your private messages.

I too have a '59. I got started a few years ago working on my radio but never got a chance to finish it. I did a little research and I think my has a bad output transformer - apparently the germanium transistors in the output stage line to go bad.

I need to get back on the radio fix some day!

Gabe,

Just as a FYI (you may already know this ) the original output transistor DS501 can still be found on several antique electronic sites including eBay. The equivalent replacement is the NTE105 or the older ECG105 while the 2N441 was the non-Delco replacement back then.

Now these are not cheap, just make sure everything in the output side is normal especially the bias resistor and the filter caps around the EBC, you do not want to blow an expensive part.   

Good luck..!

[Gabe Davis]

Thanks J. Gomez for your insight!

I actually went and got an NTE105 (I think on ebay, several years ago) but never installed it.

I was feeling confident about working on the Cadillac radio after successfully restoring a Fisher 800C tube receiver but life happened and I haven't had a chance to circle back around.

My antenna is stuck in the down position so the whole radio chain needs some love.

[J. Gomez]

Thanks J. Gomez for your insight!

I actually went and got an NTE105 (I think on ebay, several years ago) but never installed it.

I was feeling confident about working on the Cadillac radio after successfully restoring a Fisher 800C tube receiver but life happened and I haven't had a chance to circle back around.

My antenna is stuck in the down position so the whole radio chain needs some love.

So you need a 26 hour day to get back to it just like my to-do list. 

[bcroe]

That 59 Cad radio is covered by H. W. SAMS photofact AR-10.  You might
pick up this manual (31 radio  formodels) on Evilbay, or order just that
radio direct from SAMS, probably at higher cost. 

I got tired of always broken power antennas, now install a simple
stainless mast with a spring at the bottom, permanent fix.  Bruce Roe

[Paul]

Gents, thanks for all the suggestions and help. I'm going to pull it this weekend and I'm going to go through it. My brother is good with electronics, so we will tinker with it and see what happens.

On a side note, any suggestion for a device to add FM signal? I've heard of Rad Radio? I've also been directed to have it rebuilt with FM capabilities...any thoughts on a better way to go?

[bcroe]

Better decide what you want before starting repairs.  An FM signal
can be fed into your radio.  But if you want stereo and anything else,
a complete rework is needed.  Scrap your internals and your speaker(s),
build up a new system into the old chassis.  Specialists do this for a
reasonable price.  Bruce Roe

[Eric DeVirgilis CLC# 8621]

I would forget about FM stereo or modifying the radio other than to add an FM converter that can be easily removed, if FM listening is desired.

Impossible to get the correct L/R stereo soundstage from the front/rear speaker configuration used in the '59 Cadillac therefore a waste to reconfigure the unit for stereo reception and from what I've heard, FM conversions have poor reception ability and spotty quality. Maybe they have been improved since, I cannot say.

The place for critical hi fi listening is in the living room, not antique cars.