TRF Radio Circuit Atwater Kent Model 20 4640

This radio will play with out an earth ground. There is another RF return path, that is through the 0.2mf as before, then through the left rheostat over to the negative terminal of the A battery connection. Forgot to mention this in the video.
TRF Radio Circuit battery set 1920 01A vacuum tube Atwater Kent 20 4640

[@WorldWideMoose]

I’ve been playing with radios since I was 14 years old in 1969, got my ham license in 1977, and this is the best explanation of how a TRF circuit works I have ever seen. Thank You! And yeah the 20’s radios are the most beautiful to look at inside and out.

[@AllAmericanFiveRadio]

THANK YOU!

[@kennethdaust3793]

This is hands down the best video I’ve seen explaining an antique radio

[@AllAmericanFiveRadio]

THANK YOU

[@AllAmericanFiveRadio]

I meant Audio Interstage www.tubesandmore.com/products/transformer-hammond-audio-interstage-5-watt

[@AllAmericanFiveRadio]

Thanks CameramanLink It's magic! The detector is multitasking with out time slicing. It works because the audio frequency and RF frequency are far apart. But the RF amplification , RF rectification into audio, and audio amplification do interfere with each other. However it was a great circuit for the 1920s and save the manufacture cost and therefore their customers.

[@GroverCricketDaisy]

Great explanation. There is a lot to follow I will be back to review this multiple times 😊

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@AllAmericanFiveRadio]

Thanks HD7100 I think the AK TRF is a good example of the 1920s radios. And they did vary the design, like your 7960. But overall still the same TRF design. I also think it is a good starting point for the beginners. Plus the history too. And another good think is, AK made millions of this radios and not very hard to find.

[@AllAmericanFiveRadio]

Thanks AndyDaviesByTheSea Hey Andy, Yes there has been a number of name changes over the years. I think the first one I ran into was when the condenser name was changed to capacitor. I remember asking the electric shop teacher what was the difference? He said it was the same thing. I thought, whats wrong with condenser. Also the tube HeathKits I built used V1, V2,...V6... in the wiring diagrams, of course the V1 is Value1. 73's Rick

[@AllAmericanFiveRadio]

Thanks CameramanLink My guess would be lots and lots of experimenting in laboratories and/or looking over Edwin Howard Armstrong's shoulder.

[@CorporalColeco]

That was a great video! I have a 1920's Malone Lemmon Neutrodyne Reciever that will run on three tubes. Is this nomal? The two tubes that i believe are in the amplifier circuit seem to have little effect unless I turn the rheostat up. As those two tube begin to glow the audio begins to decrease.

[@AndyDaviesByTheSea]

Thanks for that Rick You talk about how the symbol for the tube has changed, I wonder if the name has changed as well. In my lifetime (60 turns on the coil as they say) condensers have become capacitors, accumulators have become batteries and aerials are slowly turning into antennas. In the UK we still refer to "TV aerials" (that's for yagies not dishes) rather than "TV antennas" as a radio ham I use both terms and I wonder if you ever called "tubes" "valves" in the States. 73's Andy

[@AllAmericanFiveRadio]

@CorporalColeco It would be hard to say from here, but if you are close to an AM station a TRF radio could preform that way.

[@grinninggoat5369]

I am currently working on an atwater kent model 42 (late 1920's). Will it work without an antenna ground as well as the radio in the video? It was sold to me as formerly working but with broken tubes from a fall during moving. Before replacement of tubes, caps & resistors, the only sound I could get out of it was intermittant popping and scratching when at the each end of the volume knob. Now, after replacment of parts and inspection of chassis components to include coils and of volume rheostat, it still does the same thing. I must be overlooking something simple. I have a very stong local station and can't pick that up or even get constant static over the speaker. The speaker is in working condition. I thought it would receive without a ground from my work table.... could this be the issue, no antenna ground on this model? All 7 tubes checks good.

[@AllAmericanFiveRadio]

I have one, and it does work with just an antenna and no ground.

[@grinninggoat5369]

@@AllAmericanFiveRadio , thanks for the answer of ground... guess I'll keep on plugging away for the sound issue. Have a great day on your great channel!

[@JimmerSD]

Nice job explaining this. Thanks.

[@AllAmericanFiveRadio]

Thanks JimmerSD

[@AllAmericanFiveRadio]

Thanks raddios2

[@hhhh3551]

thank you very much help me please to send me wiring diagram grundig c2600 radio you are good teacher thank agaian

[@AllAmericanFiveRadio]

+Rastaa Marley www.grundig.owner-manuals.com/C2600-service-manual-GRUNDIG.html