Radiola III-A 1924 Circuit and Demo

[RetroPCDOS]

Very good video and nice radio.

[AllAmericanFiveRadio]

Thanks RetroPCDOS

[tectalabyss]

Thank you sir for all the time you put in to make these very informative videos...I'm 50 and learned from My dad your never to old to keep learning...and to whoever disliked this video Shame on you !....Thanks again.added to my favorites & Playlists...Tec

[AllAmericanFiveRadio]

Thanks tectalabyss

[WB8MHE]

Hi, Rick,

A very good and informative vidio. But I have one question. I noticed that the push-pull output xfmr was not exactly ballanced. That is, the xfmr had differint resinstance from one side to the there. Is there any particular reason for this or what? Can you expound on this?

Thanks for your fine videos, and for your fine info.

Dick, WB8MHE

[AllAmericanFiveRadio]

@WB8MHE

They where going for the highest output, not fidelity. Notice that the output is across the primary coil and there is no secondary.

[Thermionman1970]

This video is so informative and really explains the signal paths and workings of the radio! AWESOME! Gorgeous radio too!

[AllAmericanFiveRadio]

Thanks Thermionman1970

[M0nk3m4n]

Yours has got to be my all-time favorite youtube channel...so glad to see all this information right here to learn from. :D

Thank you so much for your hard work!

[AllAmericanFiveRadio]

Thanks M0nk3m4n

[M0nk3m4n]

@AllAmericanFiveRadio You're welcome, sir. :D

And to save ya some trouble, you could call me Doug. I know my username is ridiculous to type. haha

[HAL4400]

Very nice video! very simple made, but to last ! interesting tubes those WD-11's

they really work like single transistors more or less.

[AllAmericanFiveRadio]

Thanks HAL4400

Yes a triode function is simular to transistors. It is a simple circuit and complex too. That regen tube is doing most of the work to make the radio receive stations.

[1fornone]

Can't thank you enough for posting all these informative radio diagrams and demonstrations. It makes me smile when you tune in a radio station on these antiques and there is an advertisement being broadcast that tells you to visit a website !

[AllAmericanFiveRadio]

Thanks 1fornone

[mrvesteraas]

I love watching your videos about old radios and how they work!

[AllAmericanFiveRadio]

Thanks mrvesteraas

[mrmardy]

MAny thanks for sharing your video,s on this. What voltage are the battery supply,s?

[AllAmericanFiveRadio]

Thanks mrmardy

The voltages I used with 01A tubes was 5V for the A battery, 20V and 90V for the B batteries, -4,5V for the C battery.

If you have WD-11 tubes then it is 1V for the A battery, 20V and 80V for the B batteries, -4.5V for the C battery.

[AllAmericanFiveRadio]

Thanks raddios2

[CameramanLink]

Great demo and explanation! But I'm still confused about a few things:

How does the tuning work (where is the "C" in the LC tank)?

What is the purpose of the "1st Stage" connectors?

How does the output transformer work with the horn speaker?

That first tube sure has to do a LOT! It's interesting to see how different these radios are from the very common AA5 designs.

[AllAmericanFiveRadio]

Thanks CameramanLink

The "C" is built into the coils so the tuning is accomplished by changing the "L", a movable coil.

The "1st Stage" is for earphones.

In a Push Pull output, each point (1,2) and (4,5) are 180 degrees out of phase. So when one point is the most positive the other point is the most negative. Push Pull gives a larger swing in voltage.

[AllAmericanFiveRadio]

@CameramanLink

Yes the first tube, amplifies the RF and the positive feed back RF, rectify this RF which demodulates it to an audio signal, and then amplifies this audio signal.

[metalmoto]

Please make more of these educational videos. I have a collection of antique radios that I would like to get working some day. You are a excellent teacher, and you are helping me better understand how these circuits work.

[AllAmericanFiveRadio]

Thanks metalmoto

[joernone]

Rick,

Yet another interesting gem pulled from the McWhorter secret stash. Sounds good. And hearing it transmit was pretty cool.

Thanks, my friend.

BTW...I'm currently in the throes of a broken Sparton that's kicking my butt. It won't make a sound no matter what I do. I hate those types.

Regards,

John

[AllAmericanFiveRadio]

Thanks joernone

Hey John,

On radios like that, sometimes I have to remind myself that they were designed to work.

Check plate voltages. Hope the oscillator is oscillating.

Regards

Rick

[aerofart]

Very nice. Thanks for sharing!

I'm just learning electronics myself and have set a long-term goal of someday building or restoring my own tube amp or early model radio.

[AllAmericanFiveRadio]

Thanks aerofart

When you decide to start replacing capacitors, take your time, and just replace one capacitor at a time and you be fine.

[gadget73]

I'm guessing the various antenna taps are for different length antennas? My Atwater-Kent has a "short" and "long" antenna connection. Never seen one with 4, but I've never owned a radio quite as old as yours. My oldest is a 1926 Freshman Masterpiece with a TRF circuit.

[AllAmericanFiveRadio]

@gadget73

Yes, the antenna is part of the tuning. I like all the 1920s radios and they are getting harder find.

[SpeakerFreak95]

really nice radio! ...,,,

[AllAmericanFiveRadio]

Thanks SpeakerFreak95

[ntydk]

Thanks for the video and sharing your passion with us.

[AllAmericanFiveRadio]

Thanks ntydk

[maahal]

My cats are all hiding now. Feedback scared them..........

[AllAmericanFiveRadio]

Thanks maahal

lol

[bbugin4u]

This video is the best.. I ready to fix radio's now (ha ha) .. I'm standing by for your next one... Thanks for taking the time and showing all of us the regentive circuit.

[AllAmericanFiveRadio]

Thanks bbugin4u

[AndyDaviesByTheSea]

Hi Rick another lovely video, you do it so very well.

I'm sure that if you bottled it you could sell it! I know you sell your books but it's great that you've made this information and knowledge free for all. I wonder for how many years this it'll stay on YouTube? Did you ever see the old movie 'The time machine' all the wisdom was contained on small spinning discs? The problem was that future generations forgot to look at them ...

Kind Regards ...Andy

[AllAmericanFiveRadio]

Thanks AndyDaviesByTheSea

I have wondered how long videos would remain on YouTube. I thought about reading up on it but then I thought, they can change the rules anytime they want, so why bother.

Books? We have books.

Regards

Rick