Delco Wonderbar Mystery
 

Hi all, I have a 1959 Pontiac "wonder bar" that has a missing tube. The model is 988977, but sams has no listing for it and all the other radios with a similar number are not like this one. I found a 12AD6, 12EK6, 12DZ6 and 12DV8. There is a missing 9-pin tube that is likely the preamp to the output transistor. nay ideas what that tube might be, I prolly have it.

Dave

https://lh3.googleusercontent.com/Sn...sSE=w1256-h779
https://lh6.googleusercontent.com/2r...a-0=w1256-h779
Should be the ones your looking for volume 19 1959 page 30-31

https://drive.google.com/file/d/0B2X...ew?usp=sharing
https://drive.google.com/file/d/0B2X...ew?usp=sharing

http://makearadio.com/beitmans/

:lmao: Comedy reply: The tube you're thinking of probably starts with 12.

Somewhere out there is a database that you can enter 3 or 4 known tubes and get a list of units that used them. Possibly radiomuseum?

Being a pontiac product there's also always the chance that someone still has access to an old GM parts-list for a vehicle that came with it as standard that might list tubes. (It would not surprise me one bit if they had GM / Delco / Mopar branded tubes just because they could.)

Hi Dave:
The missing tube is a 12AL8 according to my SAM's Auto Radio Manual.

Gregb

I was going to suggest that tube as well.
IIRC, it's the trigger tube for the search function.
BTW, I tried to download Deja-Vu from the Make-A-Radio website, so I can access Beitmans schematics. All I got was tons of corruption. My other computer is almost totally useless. :sigh:

Hey DJ, your right, the trigger tube. I just fixed a wonderbar for a guy and it was missing the same tube, must not be a very common tube.

Gregb

Thanks Greg! I have about a dozen NOS 12AL8s and all the others.

These are the oddest tubes with only 12.6 on the plates and a "space-charge" grid 1, exclusive to car radios.

I recapped this radio last evening and now just need to plug in a new 12DV8 and 12AL8 to see what kind of noise it makes.

The owner told me that "wonderbar" was like the original seek function, I wonder how well it worked, since Delco seem to offer it only during the late 50s.

Paul, I will try the Beitmans and get the right file reader, since it appears quite helpful like NostalgiaAir. There are just too many holes in my Sams and OEM schematics coverage.

Hey Dave:
If you need a copy of the schematic, let me know.

Gregb

:thmbsp: I'm not trying to nit pick or play "Mr. Internet Expert" here , but , the wonderbar radio was available in at least as late as 1964 , as I had a 64 2 door caddy that had it . My 1961 and 1958 caddys had the wonderbar as well . It was , as your friend said , a signal seek function that when the bar was pushed (my 58 had a button on the floor , next to the high beams , that would activate it as well) it would mechanically tune the radio to the next station with signal in an ascending manner . When it was pushed enough to reach the "top" of the dial (1600 KHZ) it would then snap back to the bottom of the dial (540 KHZ) to begin seeking again . Any strong station would get it to stop on that signal .

PS , I went through my automotive "Aircraft carrier" days back in the 1970s , and so my caddys are long gone now .....

In the late 70's 'signal search radios' (wonderbar was no doubt trademarked) were options in Lincolns too.

Most of what I know about Wonderbars came from reading Autotrader, Hemmings and similar ads for classic cars. They seemed to be in Corvettes more than anything else.

Its nice to know more were made and I could get more to restore, since this one came to life easily.

After replacing the missing and the weak/shorted tubes, the 8 wax capacitors and electros, it really received exceptionally well and sounded good for a Delco radio of any vintage.
I was using my 120 foot outdoor wire antenna stretched between two trees, so maybe a 30 inch car antenna may not work as well.
When the bar was pushed the first time, it muted and the motor moved tuner ahead, but not to an active station. Each time after that, it wouldn't advance much, but trying like it was not getting enough voltage.

I was afraid to just start applying lithium grease all over the tuning mechanism, figuring there was a prescriptive method. The tuner seems to operate freely enough.

Is there a method to lubricate these worm-gear motors?

:) Thank You Tom , I appreciate the help with the signal seek feature , I had the caddys with it , but most of my other , non GM cars back in those days were things like Mustangs and one really fast Road Runner . Go fast cars never had the luxury appointments like the pricier caddys and Lincolns had . As a funny aside , the white 61 in my photo had the auto dimming high beams and believe it or not the unit that reacted to the phototube's input had 2 vacuum tubes in it ! I know most folks know of the tube car radios , but to see tubes doing other functions like the auto dimming lights was a kinda cool discovery when I first opened the unit and saw the tubes . They had the "Guide" logo on them that you were discussing in your thread about your car . Congrats for it , BTW , I hope you get great service out of it . :thmbsp:

And as to lubricating anything in these old car radios , I would do nothing without first speaking to the guy over at ARF who rebuilds classic car radios , I don't remember his name but he had an avatar of a 60's Tbird trunk full of old car radios ...

Hey Dave:
The wonderbar I fixed did exactly the same thing, would not grab a station. It turned out to be the 100pf mica coupling cap from the second IF transformer feeding pin 8 of the 12AL8 tube. Changed that and away it went.

Gregb

Yep! The first one that I remember seeing/repairing was in an old 1954 Corvette "Blue Flame 6" that belonged to a friend in High School. Boy, I wish that I had that car even with its crummy 2 speed "powerglide" transmission and 6 cylinder engine today!

jr

Tube based auto dimming lights...Wow that is really cool! The auto dimmer module on my Lincoln from the light sensor to the output, with the exception of user sensitivity control, is all SS and potted to keep prying mechanics fingers out of it. I've yet to verify whether that sensor module still works, but even if it does not I'm happy just to have the lights responding to foot switch properly as they now do. Thanks, and I hope you enjoy that wonderbar.

It was called "The Twilight Sentinel" it also incorporated a auto-dimming feature., and a timer that kept either the right, or left headlight and turn light on the same side lit for a short time after you shut your Cadillac down to light your want to the door.

I changed the 100 pf red-block mica capacitor, which was right under the PC board but I have the motor issue yet.
It seems frozen or stuck and looks like its really packed in there. I'll try to access it somehow.

The motor in mine made a lot of noise and seemed to be slow. I was able to get a couple drops of oil into the bearing on the output shaft and that fixed it right up.

Gregb

I could be full of it, since I haven't touched a Wonderbar for at least 40 years, BUT, if I recall, the return was by a solenoid and the drive was provided by a spring. (You do need a decent power source to activate the solenoid, if I recall) Cleaning and sparse lubrication may do it, but don't over do it as lube tends to collect scuz....

Jim

The earlier ones were like you describe, my 53 Buick had the solenoid and spring. The later ones like this one have a motor.

Gregb

Well, that was it!, Thanks Greg - a few drops of oil on the worm drive and holding the radio in a way it runs into the motor did the trick. I also assumed these units function as if there is a hold-in contact and the bar is pressed only momentarily, but that is not the case. You need to press and hold the "wonder bar" UNTIL it advances to the next strong station, last night it was consistently stopping right at KYW 1060 and 2-3 others.

That motor is pretty small but draws about 3.2 amps when initial power is applied and drops to 0.5 amps when advancing the tuner, which it does now. That taxes my bench supply and voltage drops to 6 upon starting the motor, but it does work now.

I can see how useful this function was; All the presets are normally set for your area, then you take a road trip and have to twist the knob. How much better it was just to push a bar in and have it stop pretty close, if not spot-on, to the next powerful station. Pretty helpful in the days when distracted driving was to be avoided:D

Hey Dave:
Something is still not right, you should be able to just push and release the button and it will search to the next station. You don't have to hold the button.

Gregb

Its working now, just my power supply's poor regulation. On a car battery its performing just like it should - Thanks!

Sounds good Dave. I don't know how much car radio work you do but Parts Express has a 6-15 volt 22 Amp regulated and fan cooled power supply for under $200. I bought one and it works great and has more than enough kick for any car radio I have come across.

Gregb

Another trick is to get a used car battery charger and a 25V 2200uF capacitor to wire in parallel with it...Mine can do 20A before the fuse blows, and with the cap is clean enough to power a radio.

A note for anyone following this handy tip: Make sure that the "used" charger you're buying is of the "boatanchor" variety. The newer, lighter SMPS based chargers need some modification before being used as PSUs, and need serious filtering/chokes to be used for AM radios. "Boatanchor" types just need a filter cap and maybe punch a few holes and drop a fan into the case so they don't buzz and drive you insane after warming up. If you luck into one that has an "engine start" option you can build a small scale spot-welder. (These are usually the on-wheels variety, bigger than a "boatanchor" but I can't call them anchors because they're inherently mobile!)


If you find an identical pair of 10A (Heavy-Duty) or 20A (Marine/RV) chargers, you can extract the transformers and back-to-back them for a 130VA or 275VA poor-man's isolation transformer. Alternatively you could run 66 or 133 12AU7s in parallell. :arrow:

Good point. Mine is a Triplite brand line transformer and diode type unit that also can function as a 550W inverter.
If it ever dies it is heavy and small enough to make a decent anchor. LOL.

It actually has enough nuts to start my 4 cyllinder liquid cooled riding mower when the battery is too weak to convince the starter motor to budge it's self.

I used to use the battery charger and cap trick and they work ok for the standard 12 volt radios. The problem I was running into was 6 volt stuff and 12 volt tube wonderbar radios, the wonderbars take a pretty good surge of power to work properly and I found the battery charger would sag to much and not allow it to work properly.

Gregb

Why not plug the supply into a variac and while measuring the charger output crank it down to 6V for the 6V radios.

I guess I could have done that but I do a LOT of car radio repairs and I needed something reliable on the bench and ready to go when I needed it. I don't have the time to coble something together every time I needed it. I also find a good regulated supply gives much better results.

Gregb

A 6V radio draws twice the current of a (all tube) 12V radio. That might (or might not) be a problem, depending..