Can someone share a good source for solid state vibrators you may have used to replace the mechanical?

Looking at a Colonial Radio for a friend from his 39 Plymouth, a 6V system, and I'm reasonably
certain the Vibrator isn't working (never heard any vibs while in the vehicle). The original vibrator
is 43697M. I'm in no hurry as I still have to evaluate, and obtain caps, etc.

Bill Newman in Shelton WA is a member here and also a dealer for the solid state vibrators.
I just can't remember his handle on this forum at the moment.

Antique AElectronic supply in Tempe, Arizona also sells them along with Antique Automobile Radio in Florida. Harry

Make your own, just cross couple a pair of 2N3055 xistors. You can also GOOGLE "solid state multi vibrators".

So a search on this site as a great FET version was designed and posted on here some time ago and it covered either polarity

Carl

Thanks guys,
Searching away I went. Haven't found the FET circuit yet, but saw the 2N3055 design last night. I'll have to find it again though.
In the meantime, before I did anything, I removed all tubes from the set, including the rectifier (an 0Z4).
Connected up a variable bench supply (sadly only capable of 1 Amp but it's what I have handy) set to 6VDC. The Vibrator was dead
just as it was while in the vehicle.
Then I found this post from MAG, viewtopic.php?f=19&t=173181
So I made myself a suicide cord and connected to a porcelain light fixture, as in the diagram, works like a champ.
The vibrator was vibrating for likely the first time since the mid 60's, I let it run for the recommended 30 seconds.
Put the vibrator back in the radio, tubes still removed and reconnected my power supply, it now vibrates with 6VDC on it.
At least I now know it'll vibrate once I can get it on the bench with a real Supply.
Ultimately I will still try to find or build a Solid State Vibrator for this, for sake of reliability and to help keep the noise floor down once ready to give it back to my friend.

Thanks Frank;

Have lots of 1015 P's and N's (4 pin) for the 6 volt sets.

Also have the 2215N for the 12 v

www.billtheradioguy.com

billn

majortom,

Please be sure to replace the buffer capacitor(s)!

And you should talk to your friend to make sure you know what he wants. If he wanted quiet, I expect he would not be driving a '39 car.

Just my 2 cents, but part of the charm of the old car is that nasty buzz from the dash. Now, if it would only play Gabriel Heatter, Glenn Miller, and Amos & Andy. Perhaps you might hide an mp3 player and transmitter in the car, to back-date the programming a few decades.

Ted

If I was driving a Ford Id expect the buzz, it Im in my 38 or 40 Buick Roadmasters I expect the luxury of silence

Kidding aside the Philco vibrator used in many pre WW2 Fords was loaded with sound deadening foam.

Carl

Usually Lurking,
Understood. He doesn't know what he wants. Long as it works he'll be happy.
It's a long way from making it back in to his 39 Plymouth.
I wouldn't throw away the original vibrator on him obviously.
I just don't wanna hear him when he's rollin down my street, disturbing the reception on my own antennas.
One less noise generator out there is good for the radio environment. LOL

For kicks, or rather for just practicing my point to point soldering skills, re-capped this old
Eico 377 Audio oscillator (dated ~ 1965) I had laying around in the basement.
Wasn't really needed, nor do I really ever use the Oscillator for anything. Wanted to do this
just for practice before jumping in to the Colonial under dash radio.

In doing this ahead of time, and seeing how clean the Eico Oscillator was in comparison I've come to the conclusion I'm probably gonna want to replace some of the point to point wiring in the Colonial. Some of it is in rough shape as it is , and in some tight spots where if ya disconnect a wire from a tube socket to get at a cap for instance, ur never gonna be able to strip it back to solder it back in place nice & clean. Some in places where it looks like it might chafe through with vibration, etc. Vibrator Pwr supply to main chassis has a real tight bend against sharp edges, and obviously all is aged. Though I have seen much worse, case in point, the Zenith 7-S-529 I recapped back in the 90's was in much worse shape wiring wise. Had to replace nearly all of that wiring, one by one on that back then. That's the only other antique radio I've really ever worked on. Still plays nicely today.

So far so good with this. Finally got around to recapping the Colonial 600 Universal 6V radio. Connected it to the only power supply I have available at the moment, just a 0-30 @ 1A current limit. With all tubes removed except the rectifier, the vibrator at least started up on it's own, and the 0Z4 Rectifier tube was glowing blue.
So I guess now it's time to borrow the HP 0-30 V supply I have available at work, which will have plenty of onions to drive the vibrator supply, and bring it up slowly.

Finally got around to getting this radio back in to my friend's '39 Plymouth.
Put it all back together and bolted it back in. Works like a champ with the original vibrator.
I told him if it ever stops vibrating, we'll get a solid state one for it later.

here's a picture of it running in case anyone wants to see it after being restored (err fixed).

http://db.tt/rvxo2bwJ

Love those old car radios. Played around with a lot of them when I was a kid, and a few later on when I was an Electronics tech. Even got to work on a couple of 1937 Cord radios for a friend. The Delcos were built like tanks but I think the Philcos had the best sound. BTW: Delco vibrators also were foam packed. I used to take them apart, clean the points and reuse them. Car radios weren't any fun anymore when the went to solid state.

Jim

The problem with the solid-state vibrators that I've seen is they have no open interval.

A real vibrator holds the contacts closed on one side for a portion of the half-cycle, then
opens them for the remainder of that time period. This open interval is important.

The idea is that the magnetic field generates a reverse voltage as it collapses. When the
contacts close on the next half cycle the induced voltage is of the same polarity as the
reverse voltage from the previous half cycle, thus reinforcing it and continuing the
current flow in the same direction.

If there's no open interval, current through the transformer primary is switched instantly, which
causes huge current spikes in the system. This stresses the transformer. Whether it would
actually damage the transformer or not depends on the overall design and construction.

- Leigh

hmm, the ol L di/dt story (thus the 1600V buffer cap).
So if ya used a solid state vibrator (switching time goes down, di goes up ^^ = more L di/dt), ya may have to increase the voltage rating further on the buffer cap?
I suppose if it was my radio I would be willing to experiment.
Seems to be working fine as it was designed with the mechanical vibrator, so will leave well
enough alone for now.
here is the riders on it, it's the first model in the PDF.

http://db.tt/9zyHoTGN

I forgot one important point in my previous description...

The timing in the system is precisely controlled such that the contacts close at the instant
that the reverse voltage crosses zero volts, which minimizes contact pitting.

- Leigh

I have used several of the 1015 SS vibrators and had very good results, one I did about 8 yrs ago and still going strong. They dissipate almost no heat. Here is a pic of the inside

I have used one for about 10 years, with as much radio operation as possible, even left on by accident..Radio still as slight audible buzz, not hum..not a physical feel like mechanical unit. They are great, but unforgiving, as when testing a set on the bench and accidently shorting something in power supply..they are immediately toast..as opposed to old point style..so I now keep an old one for bench use..here is mine in use, slightly static in the garage with not ideal reception..
http://www.youtube.com/watch?v=K1To8tZseVM
this is another in progress till i shorted it out D'oh
http://www.youtube.com/watch?v=gRJd8lwKHeI
http://www.youtube.com/watch?v=xU8-l3v79jo

I was sort of amused with the u tube thing always liked making movies