[Guest]

Hi,
I am trying to get a PHILCO CR-2 car radio working. I found that the vibrator is broken and needs to be replaced. I found this schematic which I think would be suitable as a replacement, but it's not the same pins on the vibrators. Mine has four legs, two thin and two other thicker pins, and not six as the schematic shows. I took the vibrator apart and one of the thicker pins isn't connected at all.
The vibrator has a number printed on the top, "83-0025".

[denver]

Just hang on you,ll start getting alot of exspert advice .

[Guest]

Ok, ;).

I think I've put this post in the wrong category, maybe a moderator should move this to the "Philco Electronic Restoration" category.

[BILL]

YES you have the standard 4 pin vibrator ,your set has a tube for a rectifier, it's the most common vibrator ,transistor replacements are available, but make sure of the condition of your power supply!

Here is something to try with your old vibrator, buzz it on AC,in series with a 40 watt light bulb,That may get it going , also REPLACE that buffer!

[Guest]

Unfortunately, the vibrator is broken. I'm not able to get it going again because two metal things has fallen off of the contacts, so it's beyond repair.
I don't wan't to buy a new transistorbased vibrator, I wan't to build one myself. ;) What's a buffer, and what does it do?
Here's the schematic diagram of the PHILCO CR-2 radio.

[BILL]

The buffer takes the damaging arch out of the vibrator points, your power supply works about the same as the distributor,in the old cars vibrator=points, buffer= condencer, transformer= coil, to get your high voltage AC, then your 7Y4 rectifier converts it to high voltage DC for your "B" voltage , your buffer is C 19 on your schematic, looks like .015 mf , most are .006 mf, put in a 1600 volt one, most likely the buffer is leaking and was drawing too much current and burned up your vibrator, may have damaged your power transformer and even vibrator hash. Many times people would just change the vibrator and end up doing a lot damage to the radio, with a shorted buffer a transistor vibrator would last a few seconds .,BILL

[Guest]

The transformer is fully working. C19 in my radio is a 0.1 µF 1000VDC/500VAC, I've measured it and it's in a very good condition compared to the other caps in the radio which I have replaced, but maybe I should replace this one as well? It isn't leaking and it's not an electrolytic cap.
Actually, the 7Y4 rectifier tube is replaced with an identical tube called 7Z4.

[Ron Ramirez]

I think I've put this post in the wrong category, maybe a moderator should move this to the "Philco Electronic Restoration" category.

It's in the correct category (Philco-Transitone Auto Radios).

Carry on, folks...

[BILL]

REPLACE IT! beleive me ,for the cost of it, replace it , You could if you really want to use it to replace a lower voltage cap. .
When you tune up an old car you usually replace the points and condencer do the same here, I've used old buffers when they were not original and had been replaced before ,only to have them short out a year or less later, BILL

[Guest]

The capacitor has now been replaced. =)

Until I get a working vibrator, can I test the radio by applying a low AC voltage on the input of the transformer (where the vibrator usually is), and slowly increase the voltage until I get the acquired anode voltage from the rectifier tube? And also applying the 6 volt DC that the radio needs to operate.

[BILL]

What you need is some kind of interupter, I have put 275 DC on the "B +" by passing the power supply and make the radio work, I did this once on a 8 tube 1955 Ford radio, had BAD noise interference, noise went a way with original power supply out, turn out to be that some one had put in the wrong vibrator hash. I had gotten this radio when I bought out an old radio repair shop, they had written "JUNK" on it , they couldn't figure out what was the problem , sometimes it just takes time and experimenting, BILL

[codefox1]

This is a part of an earlier response:

Back in the old days, when my dad sent his old Packard to the bone yard, I took the radio out the night before. Of course I didn't know what I was doing, but I took an old television power transformer, connected the 6.3 volt windings to the tube heaters, removed the vibrator, and hooked up the h.v. from the old TV transformer to the plates of the 0Z4, at least that's how I remember it. To my utter amazment the radio played very nicely. I was around 12 years old at the time.

[Guest]

Yay! I've got it working!

I finally found a schematic on the internet for a four-pin vibrator, but for use with a positive chassis, so I modified the schematic a bit. I used two BD243 NPN power transistors in place of the two PNP TIP34. I also replaced the two 2N4234 with two NPN BC639. I mounted everything inside the radio and now plays it, wonderful! I can receive many stations as I tune the radio (I live in Sweden so there are not many stations to receive). I haven't got a power supply powerful enough, so I'm using a couple of lead acid batterys to form a 7,5Ah 6V battery.

[Johannes]

Hi,

I have the same problem with the vibrator.
The guest wrote he managed it with a self made electronic device.
And wrote that the Philco car radio was working fine again. 

Can you please send me the schematic? Because when I click on the link it gives an error.

Kind regards,
Johannes.

[Ron Ramirez]

Ah, the constantly changing internet...old pages go away, new ones appear...

Sometimes the Wayback Machine can help, sometimes not, In this case, yes, it can. Try this link:

https://web.archive.org/web/201010221449...db1008.htm

And, by the way, Johannes, welcome here!