The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench took a radio out of my truck and need some help getting it running

hey guys, hoping one of the radio doctors can help me out here, I just took the radio out of my "Big GMC" (1950 350 series ) and discovered it is a Delco from the correct era but it is an oldsmobile radio... even says deluxe on the faceplate. ok the radio number is 982544, it is a 6 volt radio and I beleive it was used in a negative ground application ( I know it does not matter with a mechanical vibrator )

here is deal I researched around here a lot and read the tech article on fixing these things, so I took her apart ( well uncased it anyway ) cleaned it up and looked it over good. I then located and unplugged the vibrator and powered her up. yay dial light and heaters .. no smoke and all was well. I powered it back down and installed the vibrator and tried again, same results.... no hum from the vibrator and no reaction from the glass OZ4. ok so I took the vibrator back out and powered it up again, and am getting 6v at two of the pins on the vibrator socket....so bad Vibrator right ?

well I figured since I was replacing it I may as well open it up and take a look.... Suprise! a VERY high quality part, well sealed with a nice natural rubber sleeve around it for dampening and WOW, points were great no signs of over heat and a little ohm checking rvealed the points work as advertised, just do not vibrate. SO I am thinking the Tank circuit that cause it to ring likely has a bad cap?? guess I will have to dig further in the morning and see what the meter says.

I know it has been posted a bunch but because I live in Alaska and have to ship everything, is there a source for a Cap "kit" that I can just get all of the caps I need in one order prior to checking all of mine and taking them out and itemizing?

Any suggestions hints tips or Flames welcomed !
Thanks
Dan

Here is the diagram for your radio. Nostalgiaair Site

Here are two of the many online sources for capacitors .
Just Radios and Antique Ellectronic Supply My advice would be to replace all the yellow wax covered paper capacitors including the one under the metal cover on the bottom side of the 0Z4 tube. You would be wise to replace the vibrator too.

Thank you truckernix,
I have cleaned it up and lightly burnished the points.... even the old 0z4 tube lights up, no signs of distress, but I shut her down for a cleaning and re-capping. I think it can be saved ! Thanks again
Dan

I have no doubt that it can be saved so we shall look forward to it playing tunes!

Its going to be a while, I stripped it down tonight and seperated the tuner section from the chassis, taking lots of pictures. the whole faceplate ( inside and out) has been painted a hideous copper anti sieze color and the "preset" buttons are not working, however the manual tuning Dial did free up and start working again. I plan to go pretty much full bore on this and make it fairly presentable.
photo

A trick that I learned from Big Tonka was to suspend the button mechanism in some Evapo Rust to free it up. Some radios are really rusted up and that technique works great.

So you have the really big GMC with completely different sheet metal from the little guys?

Nah... Not that big it is a 2 ton, pickup looking.......just big fenders.
size comparison If you browse around here you will find other photo's of the truck and the radio.

PS, when you say suspend the buttons in evaporust.... are you taking the actual black plastic "buttons" off or just keeping them out of it ? also I am not sure I want to take the tuning inductors off the back of that assembly but I am afraid to soack them with/in anything as I am sure they are laquer coated wire in there.

I did get the buttons working, was just the spring lever on the clutch side...but the actuall lever mechanisms could sure use a good cleaning .

You might want to try and get your old vibrator working. They are nice to have when first testing after the capacitors have been replaced. The new electronic vibrators are more efficient and should last a long time but they are more fragile when it comes to shorts. I always test the radio using a mechanical one before installing the solid state version. Here is a post where I outlined how to test the vibrator. testing vibrator

Yup, I got it running, no shorts, and showing. 180 volts at the tubes from a partially run down 6 volt battery. Shut it down and started making a list of caps to order. I would much prefer to have a mechanical vibrator, do you happen to know of a source for new ones?

I don't know of a source for new mechanical vibrators. You might want to try Ebay for an NOS one.

I usually always replace the high voltage capacitor (1600 vdc) in the vibrator circuit. An 0Z4 doesn't have a filament in them. They are a gas rectifier.....

John

Yup cold cathode emmision.... BUT it still lights up purple when it is doing its thing ;-) which mine does... ran it for a few seconds and measured voltage.... but all new caps are on the list of things to do.