Vacuum Tube Car Radio Motorola 300

[@AllAmericanFiveRadio]

Thanks grassulo Yes Motorola did very will with this circuit. Antique Electronic Supply has solid-state replacements. They run about $29.95

[@Flickchaser]

AllAmericanFiveRadio--Thnx for such a quick response sir. Followed your suggestion, found the link and download accordingly. My friend was an ET(Electronic Tech) in the Navy. He got hold of an old inoperative commercial Radio from Germany,did some youtube- vac-tube- homework and got that jewel functional and lit up! His smile was brighter than the Radio dial. Best wishes to you and yours.

[@AllAmericanFiveRadio]

Thanks AndyDaviesByTheSea Hey Andy I can remember turning on the radio in my fathers 1953 Ford and hearing a quiet buzzing at first, and then the tubes warmed up, and then the radio playing. I can remember him changing out the condenser that was across the points because the points were making noise in the radio. It is amazing how things have changed. Regards, Rick

[@AllAmericanFiveRadio]

Hey Lucas Paul V. Galvin would approve. Making radios for cars was the start of the Motorola Corporation. Nice experimenting, I think that circuit was one of the first patent for Motorola. Rick

[@AllAmericanFiveRadio]

@joernone Thanks John, This was fun to put together. The applications I use makes it all possible. After getting an idea and visualizing several possibilities and testing an idea, the building of the pictures is not to bad. The hard part is still the idea and how best to make it visual. Regards, Rick

[@joernone]

Rick, That was a great video. Superb job on the graphics. About a month ago I had a conversation with a few of my fellow Ham radio club members about the old vintage radio vibrators. You'd be surprised at how many didn't know what they were...or how they worked. Some did, but most did not. I know it took a lot of work to put this video together. Thanks, my friend. Regards, John

[@LucasHubert1994]

hello Rick, i was playing with a transformer and a small relay today, i built this circuit with a 6V battery and a relay instead of the vibrator and it works!!! the relay buzzes very loud but the transformer puts out full 200V on the "primary" side! quite interesting electronics.. thanks for sharing this information. Lucas.

[@AllAmericanFiveRadio]

Thanks snakerivercycles It is a square wave but not a pretty one, that is the reason for the other high voltage capacitor in the circuit. They help to filter out the noise from the vibrator circuit.

[@AllAmericanFiveRadio]

Thanks MovieTech Yes and from the manufacturer too. Unfortunately it is not un-commend to find errors in these wiring diagrams. The "0" in 0Z4 means no filament and thanks for pointing it out too. But, not to be to hard on Motorola making diagrams changes was much more difficult and expensive back then. Another error from another manufacturer I found was a dead short in the B+ power. I tracked a wire from B+ through a weaving path in the radio to B-!!! Now that one was a bad error.

[@AndyDaviesByTheSea]

Hi Rick, one to wake up a few dormant memories. I think the last time I saw a vibrator was in the power supply for a Number 19 wireless set back in the 1960's I can't remember what the output was but I remember having the choice of either a vibrator or a rotary transformer (rotary convertor.) If my memory serves me correctly the vibrator had the tiniest of gaps with no means of adjustment and I seem to recall a tiny blue spark that "Fizzed" and the foam had a distinctive smell. ... Andy

[@GroverCricketDaisy]

Fantastic thanks I have a 1938 Buick and I intend to fit a radio in it of the same vintage. Which was an optional extra back in the day.

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@JonathanJayBabcock]

Thanks. I'm waiting for your AA5 book to arrive too. Hope that will answer a lot of other questions for me.

[@AllAmericanFiveRadio]

My FREE e-book The Vacuum Tube Shortwave Radio www.richardmcwhorter.com/vacuumtuberadio/

[@AllAmericanFiveRadio]

Thanks CameramanLink I think their all solid state at AES, which is a good idea. But you don't get buzzing sound.

[@AllAmericanFiveRadio]

Thanks raddios2 This was an early successful idea by Motorola.

[@grassulo]

some battery powered "farm" radios use vibrators in their B+ circuits too. I have seen Zenith and Philco battery sets that did. Are these vibrators often bad? And is it possible to get new ones or rig up solid state replacements? I would imagine you could make a similar circuit with a power switching transistor (like the ones salvaged from dead CFL lamps) to replace the mechanical vibrator.

[@ranuts2]

Thanks Rick, more excellent information.

[@snakerivercycles]

another great video. Does the vibrator put out "square wave" ac by chance? I've got a 1963 copy of "popular electronics" magazine detailing a diy replacement for the vibrator using two transistors. Please keep making these videos, very helpful.

[@jp040759]

Can you run this radio on either a positive or negative ground car? Does the radio care? Based on the schematic I don't immediately see that it would make a difference to the radio. The capacitor between the "A" choke and the power switch is unidentifiable as electrolytic or not. Other than that being a clue I don't see any other indicators of why the radio would care. Please explain. Thanks for great videos.

[@AllAmericanFiveRadio]

It's negative ground www.nostalgiaair.org/pagesbymodel/554/M0006554.pdf

[@jp040759]

Thank you for quick reply and info.

[@JonathanJayBabcock]

There are three filter capacitors shown. Does the 25v capacitor show a reverse orientation with positive lead going to circuit or chassis ground? Could you direct me to an explanation of this? Thanks.

[@AllAmericanFiveRadio]

I'll do a video on it maybe next week

[@AllAmericanFiveRadio]

Maybe one more week. I did start the drawings

[@Flickchaser]

AllAmericanFiveRadio-Thank you sir. Excellent instruction-Slow paced with photos and ckt. flow illuminated trace. If someone was interested in learning Radio(especially vacuum tube)theory, what book would you recommend? Best wishes.

[@AllAmericanFiveRadio]

My ebook you can find the download link on the right side of my KZbin Channel. Vacuum Tube Shortwave Radio

[@saturn5tony]

Hi Rick, as the schematic shows, Is the plate voltage greater than 180V? What is the max Voltage a Vibrator can produce? Seems really high and when you think about it, the largest volt in a car is 12!! wow amazing!!

[@sjh7132]

A few big EMPs and we may have to go back to this technology.

[@AllAmericanFiveRadio]

Thanks Flickchaser

[@AllAmericanFiveRadio]

Thanks sjh7132 Yes this would still work!

[@AllAmericanFiveRadio]

Thanks charlessmyth

[@Movie-Tech]

An 0Z4 with a HEATER? Looks like maybe the radio's original design had a 6X5 in it and they changed to the 0Z4 later (probably to save on current drain) and forgot to remove the heater from the schematic (6X5 and 0Z4 have the same pinout for the cathode and plates)...

[@billybonewhacker]

realy fascinating stuff ty for ur trouble

[@AllAmericanFiveRadio]

Thanks billybonewhacker

[@Flickchaser]

AllAmericanFiveRadio-If you have not seen this, it looks like your kind of candy-"Spy Radio in World War II:Strategic Service Transmitter-Receiver Number 1" SSTR-1 Part1-2 OSS Part 2 (Time-8:07) shows fine tuning using a miniature light bulb?? I've not seen that done before.

[@TechTins_Projects]

Great stuff. I have a friend who has old vintage Italian car with valve radio called a Gallo-Condor T5. It has a Mallor Vibrator. which has 6 Pins!! A single reed switch with not one but instead two sets of contacts!! The schematic seems to imply (I am guessing here mind) that it uses a transformer and does the full wave rectification without a valve being used. Does this make any sense. Hope you can help, it is a very odd looking circuit. There is a pentode valve in it but it comes well after the DC B plus has been made. Its very weird. Here is link to schematic www.radiomuseum.org/r/condor_t5.html Be great if you could have a quick look and tell me if my hunch is correct.

[@AllAmericanFiveRadio]

I'll be glad to try helping with your project. I have downloaded the wiring diagram. Usually the part that is hardest to find is the vibrator. It looks to me like the rectifiers are housed inside the vibrator. I have done several videos on radio repair and one of those you might watch is this one: Radio Repair Steps kzbin.info/www/bejne/mmnaiKpvZ62BkMk I also have a free e-book that you can download. The Vacuum Tube Shortwave Radio www.richardmcwhorter.com/vacuumtuberadio/ If you do not have the wiring diagram I will be glad to send it to you. You will have to contact me via regular email “[e-mail]” The first thing I would recommend doing would be to check all the coils in your radio. If the oscillator coil is open or the transformer for the vibrator is open, this could be a real problem. Rick

[@TechTins_Projects]

That link I put in last post takes you to a page with the schematic as a downloadable pdf. That is one I now have. There are two schematics one is for the power supply box (which also houses the final audio pentode valve for the speakers (el84). The other schematic (the radio itself) takes the B+ produced from the first schematic (power supply) via the plug pin numbered number 4 plug. With number 5 pin as the return which has the Audio on it from last audio amplifier plus detector valve (ebc41). So I am pretty certain that B+ plus is through plug pin number 4. That is direct from the pentode valve in the powerbox. But I think the input to that pentode valve el84 is DC from the transformer via the vibrator. It is totally fascinating! hope you can help. Please can you look at those two schematics first. They look very basic. It is just that I have not looked at valve stuff before now. So I am guessing on a lot of things. I want to get this thing working as it is beautiful.

[@TechTins_Projects]

I have your book. Got it a while back. Very good. What is procedure to check coils? Is it just a continuity check and check for shorts?

[@AllAmericanFiveRadio]

Glad you have the diagrams. The diagram of the vibrator audio output, the socket to the left is a bottom view. On the other diagram that has the mixer, IF amplifier, detector and first audio amplifier. Those sockets at the bottom where the cables mate from the other chassis, those sockets are top view, so the pins count the other way.

[@AllAmericanFiveRadio]

Yes continuity should be good, mostly opens

[@Rainbow__cookie]

So a vibrator is basically a relay

[@AllAmericanFiveRadio]

It's more like a buzzer with contacts.