Wow what a great little radio! Excellent sound as well. I love seeing the avc in action. It's amazing how they had this technology in the 30's, yet commercials in modern tvs blow your eardrums out!
Holy smoke .... I built one of these when I was in school learning about electronics back in 1968, then we went on to transistors then the first wave of IC's .... well any way the soldering iron was a huge 100 watt thing ..... lots of fun back then .... LOL LOL
Rick - another one of your amazing illustrated tutorials that keep things simple and easy to follow. As always, thank you for taking time to share your knowledge with us. All the best. Don
This brings back memories, in college our class built the AA5 radio and after getting it working and tuned, the teacher and assistant would bug them and return them for us to troubleshoot. They complained that mine was difficult to bug because my wiring was too neat. I had built many kits prior to college so making it look good was easy for me.
I had forgotten all about the really old Superheterodyne receivers that had tube filament voltages that added up to the mains voltage. One tube's filament opens and Poof, there goes the receiver until you pulled out the ole tube tester and found which one had opened up. I was glad when more radios started having power transformers to isolate the mains from the secondary power outputs.
I'm learning about superhet and vacuum tube circuits in order to repair an antique radio I inherited. Your videos are better than many of the "high brow" ones I've come across. I like your hands-on, direct and practical style. Although I worked for 20 years as an electronic technician, I never dealt with vacuum tubes or radio before.
Thank you. Here are some other videos that may help. The last link is my FREE ebook. The password is allamericanfiveradio Let me know what you think. Triode Tube Amplification Visual Demo th-cam.com/video/4FkD0LRiu7A/w-d-xo.html Control Grid, Triode Tube th-cam.com/video/K_AJRIsNlR0/w-d-xo.html How Superheterodyne Works th-cam.com/video/jQd2LfTOa4k/w-d-xo.html Password is allamericanfiveradio th-cam.com/users/redirect?event=channel_description&redir_token=QUFFLUhqa2hhVTRycWdJd1FUbTFCZWNmdGtQNlZCRmEzd3xBQ3Jtc0tuOFQ2bFhRcWdjdUdIcUREcnZFaHc0M2xURGhITVRuWDE2cGlDakdYUF9uODktNzc3TVRJTWdROUt6R3NLN2lla3hFS2lIM0RnOXR1dXFxMGx2cUNtWDhXb1Zvc2RCbGQxTThoendmN2E5R0lJdmI0Yw&q=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1HHmaWYr7UMACfmS4W5uL6PADoem2KlRp%2Fview%3Fusp%3Dsharing
Very good. When covid started I had the pleasure of restoring a 1946 Philco tabletop radio that was similar to one I had as a young boy. I was able to see signals similar to these. Thanks.
Glad to have this on youtube, a fantastic explanation of such a classic radio circuit, thank you very much! When measuring variable voltages like the AVC regulating voltage, I personally find it useful to use a analog multimeter instead of a digital one. The range of the needle movement on the scale is maybe more meaningful. But when measuring steady voltages or currents, like the measurement of filament voltages, plate or screen grid voltages, I prefer to use a digital voltmeter. When measuring the AC ripple on top of the DC voltage of the output of the rectifier stage, a digital voltmeter would be the very best choice. Best regards from Switzerland, bluearcturus
The "gold standard" of the time was to use a VTVM and look to peak the IF outputs. It still is the thing for any tube-type radio gear. No restorer or ham's bench should be without one.
I was given one by a relative when I was a kid. I modified it to take an octal socket with different coils so I could also tune the SW bands. Loved that thing. The smell, glow and warmth of all those tubes added to the mystique.
A well kept secret is that the technique demonstrated here with measuring the AVC is the quick, hassle-free, way to peak out the signal in doing an alignment. No having to keep the signal level low in order to avoid invoking the AVC effect. Thanks, Mr. McWhorter, for your outstanding videos and books!
Thank you. You may like my FREE Ebook, it is PDF. Here is the password and download link: Password is allamericanfiveradio th-cam.com/users/redirect?event=channel_description&redir_token=QUFFLUhqa2hhVTRycWdJd1FUbTFCZWNmdGtQNlZCRmEzd3xBQ3Jtc0tuOFQ2bFhRcWdjdUdIcUREcnZFaHc0M2xURGhITVRuWDE2cGlDakdYUF9uODktNzc3TVRJTWdROUt6R3NLN2lla3hFS2lIM0RnOXR1dXFxMGx2cUNtWDhXb1Zvc2RCbGQxTThoendmN2E5R0lJdmI0Yw&q=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1HHmaWYr7UMACfmS4W5uL6PADoem2KlRp%2Fview%3Fusp%3Dsharing
beautiful contribution of superheterodyne amplitude modulation receivers reminds me of my years as an electronics student when our professor victor peiroti taught us the theory of superheterodynes with their tandem variable capcitor the local ocildor coil the intermediate frequency transformer the 1n34 diode that he used to audio demodulator that separates the audio from the radio frequency of the IF. how many memories. the mathematical equations the formulas thanks for the video. Kind regards from Argentina 👍🙏📻
Thanks for the video, it's hard to retain all that's going on in these radios. I still need to watch these type video's to learn and maybe someday remember what's going on in there.
Wow! Finally! I never understood how superheterodyne works, i could not get around the mistery. This is a very informative video. I get it now, it's not that hard to understand when it is explained like this. I am very gratefull for your video! Thank very, very much!
Thank you, and your welcome. I'm glad you found this video useful. I do have FREE eBook that also may find helpful and useful. The link is in the ABOUT on my TH-cam site. Here is the information for the eBook. I hope you enjoy and find the information useful. PASSWORD is allamericanfiveradio drive.google.com/file/d/1HHmaWYr7UMACfmS4W5uL6PADoem2KlRp/view?usp=sharing
Local oscillator TRACKS incoming station frequency such that the DIFFERENCE between the two signals IS 455KHZ. This is why the variable has 2 section GANGED together. Reason why a certain frequency picked had to DO with component size. RCA patented 455KHz so others had to pick another IF frequency so no royalties would have to BE paid. AVC influence has to BE kept low while peaking IF coils. Pick really faint station, pipe in the IF frequency and peak. LOL The rectifier removes half the carrier envelope so that the audio extraction can take place. There IS so much going on. Always learning. Good video info.
So in the first tube starting at the bottom you have the cathode which feeds the inductor that feeds the tank circuit. You mentioned this was DC power but the inductor needs AC current if the local oscilator is to function? Also if I understand correctly the screen grid is the transmission signal and the control grid is mixing the LO. What are those other 2 grids that appear to be coupled together on pin 6 of the first tube, they appear to be part of the IF tank circuit?
Hey Ron, we must be amphibious or something. I am currently working on drawings for the oscillator circuit. I had a request from a TH-camr to go through the oscillator circuit in more detail. I'm hoping to be able to upload a video may be this Sunday. I'll try to remember to let you know when I have uploaded a video in a comment on this video.
@@AllAmericanFiveRadio Thank you so much, this is super helpful to build my intuition of how this works. Once I get about 80% on the tube heterodyne I have to learn the solid states. We have a Harris HT20 and BT35 Transmitters
I found an old guitar amp in the trash the other day. It contains a 12AX7a Twin Triode. I have no idea what to do with it. I'll have to re-watch all your tube amp videos!
I have often wondered why it was that automobile radios had a 262khz IF strip. Would you happen to know the answer for that? I'm stumped on it. My 1972 Philco Ford AM only radio has it. Great radio by the way. Very selective and sensitive.
Could it be said that the capacitor to ground is a high pass filter sending high frequencies to ground? But you were talking about amplitude of the signal not frequency
I was slightly confused by your statement that "The secondary is hooked up to a diode". I searched from the output of the secondary's coil thru the circuit but did not see a diode anywhere. Then, a little research for the 12AV6 tube data reveals that this tube contains both a triode and 2 separate diodes - internally, the diodes being connected to tube pins 5 & 6. Looking at your diagram, pins 5 & 6 do appear to show as diodes inside the tube. Therein lay my confusion, the IF secondary is hooked to a diode, which is integral to the tube, not a distinct, external component separate from V5. I may be dense but perhaps this will help another so confused. Great video otherwise.
@@AllAmericanFiveRadio So inside V5 is the diode, when it’s connected thusly? Ah ha… tricky that. I had to look up the tube to research it and find it has two diodes in it. I searched your diagram a long time for a diode on its own. Ha ha
Oscillators, the Basic Tank Circuit 1 th-cam.com/video/fQ4yRVEzXQA/w-d-xo.html LC Tank Circuit th-cam.com/video/8vu9WDjBAho/w-d-xo.html AM Transmitter Tank Circuit Coil Capacitor Resonance th-cam.com/video/6TRqNkT5OCk/w-d-xo.html Radio Oscillator Tank Circuit th-cam.com/video/-Q-gvhErkcY/w-d-xo.html
Simply outstanding explanation of the way an AA5 works Rick. Clear, concise, wonderfully done. Thanks! :)
Hey Doug. Thank you.
Your dedication to sharing your amazing knowledge is very much appreciated! Thank You!
Thank you, and your welcome.
Wow what a great little radio! Excellent sound as well. I love seeing the avc in action. It's amazing how they had this technology in the 30's, yet commercials in modern tvs blow your eardrums out!
Thank you, and your welcome.
Holy smoke .... I built one of these when I was in school learning about electronics back in 1968, then we went on to transistors then the first wave of IC's .... well any way the soldering iron was a huge 100 watt thing ..... lots of fun back then .... LOL LOL
Thank you. Yes it was fun!
Rick - another one of your amazing illustrated tutorials that keep things simple and easy to follow. As always, thank you for taking time to share your knowledge with us. All the best. Don
Thanks Don. This one took awhile, but I'm glad I took the time. I also learned somethings able Corel Draw.
Excellent walk through of the entire radio. Great job sir.
Thank you, and your welcome.
This brings back memories, in college our class built the AA5 radio and after getting it working and tuned, the teacher and assistant would bug them and return them for us to troubleshoot. They complained that mine was difficult to bug because my wiring was too neat. I had built many kits prior to college so making it look good was easy for me.
Sounds like a great course. Thank you,
Nothing less than fabulous !!! Always look forward to your uploads. Cheers
Thank you, and your welcome.
It’s really well explained, the demos, the calm pace, the circuit highlighting, thanks for this video
Thank you, and your welcome.
I had forgotten all about the really old Superheterodyne receivers that had tube filament voltages that added up to the mains voltage. One tube's filament opens and Poof, there goes the receiver until you pulled out the ole tube tester and found which one had opened up. I was glad when more radios started having power transformers to isolate the mains from the secondary power outputs.
Thank you, and your welcome.
Good information presented in a way simple enough that most anyone can understand and learn it. Thank you so much for posting this!
Thank you, and your welcome.
I'm learning about superhet and vacuum tube circuits in order to repair an antique radio I inherited. Your videos are better than many of the "high brow" ones I've come across. I like your hands-on, direct and practical style. Although I worked for 20 years as an electronic technician, I never dealt with vacuum tubes or radio before.
Thank you. Here are some other videos that may help. The last link is my FREE ebook. The password is allamericanfiveradio
Let me know what you think.
Triode Tube Amplification Visual Demo
th-cam.com/video/4FkD0LRiu7A/w-d-xo.html
Control Grid, Triode Tube
th-cam.com/video/K_AJRIsNlR0/w-d-xo.html
How Superheterodyne Works
th-cam.com/video/jQd2LfTOa4k/w-d-xo.html
Password is allamericanfiveradio
th-cam.com/users/redirect?event=channel_description&redir_token=QUFFLUhqa2hhVTRycWdJd1FUbTFCZWNmdGtQNlZCRmEzd3xBQ3Jtc0tuOFQ2bFhRcWdjdUdIcUREcnZFaHc0M2xURGhITVRuWDE2cGlDakdYUF9uODktNzc3TVRJTWdROUt6R3NLN2lla3hFS2lIM0RnOXR1dXFxMGx2cUNtWDhXb1Zvc2RCbGQxTThoendmN2E5R0lJdmI0Yw&q=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1HHmaWYr7UMACfmS4W5uL6PADoem2KlRp%2Fview%3Fusp%3Dsharing
Nice circuit explanation Rick. Showing the functions plain and simple.
Hey Carl, hope your doing well. THANKS!
Very good. When covid started I had the pleasure of restoring a 1946 Philco tabletop radio that was similar to one I had as a young boy. I was able to see signals similar to these. Thanks.
Hope you keep restoring radios. Thank you, and your welcome.
Glad to have this on youtube, a fantastic explanation of such a classic radio circuit, thank you very much! When measuring variable voltages like the AVC regulating voltage, I personally find it useful to use a analog multimeter instead of a digital one. The range of the needle movement on the scale is maybe more meaningful. But when measuring steady voltages or currents, like the measurement of filament voltages, plate or screen grid voltages, I prefer to use a digital voltmeter. When measuring the AC ripple on top of the DC voltage of the output of the rectifier stage, a digital voltmeter would be the very best choice. Best regards from Switzerland, bluearcturus
Thank you, and your welcome.
The "gold standard" of the time was to use a VTVM and look to peak the IF outputs. It still is the thing for any tube-type radio gear. No restorer or ham's bench should be without one.
A great review of the basics of the superheterodyne principals Rick. Thank you for the video.
Thank you, and your welcome.
Excellent explanation of the circuit, and better yet, great job at the graphics, using different colors to highlight the various signals involved!!
Thank you, and your welcome.
I was given one by a relative when I was a kid. I modified it to take an octal socket with different coils so I could also tune the SW bands. Loved that thing. The smell, glow and warmth of all those tubes added to the mystique.
Thank you, and your welcome. They are fun and interesting.
A well kept secret is that the technique demonstrated here with measuring the AVC is the quick, hassle-free, way to peak out the signal in doing an alignment. No having to keep the signal level low in order to avoid invoking the AVC effect.
Thanks, Mr. McWhorter, for your outstanding videos and books!
yes that will work nicely.
Thank you, and your welcome.
Very nice explanation and done in just 11 minutes, thank you!
Thank you, and your welcome.
There is so much excellent information in this video that I had to watch it multiple times!
Thank you. You may like my FREE Ebook, it is PDF.
Here is the password and download link:
Password is allamericanfiveradio
th-cam.com/users/redirect?event=channel_description&redir_token=QUFFLUhqa2hhVTRycWdJd1FUbTFCZWNmdGtQNlZCRmEzd3xBQ3Jtc0tuOFQ2bFhRcWdjdUdIcUREcnZFaHc0M2xURGhITVRuWDE2cGlDakdYUF9uODktNzc3TVRJTWdROUt6R3NLN2lla3hFS2lIM0RnOXR1dXFxMGx2cUNtWDhXb1Zvc2RCbGQxTThoendmN2E5R0lJdmI0Yw&q=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1HHmaWYr7UMACfmS4W5uL6PADoem2KlRp%2Fview%3Fusp%3Dsharing
A brilliant design, and wonderful presentation. Thank you sir!
Thank you, and your welcome.
I learned something today!!! Excellent video!!!
Thank you, and your welcome.
beautiful contribution of superheterodyne amplitude modulation receivers reminds me of my years as an electronics student when our professor victor peiroti taught us the theory of superheterodynes with their tandem variable capcitor the local ocildor coil the intermediate frequency transformer the 1n34 diode that he used to audio demodulator that separates the audio from the radio frequency of the IF. how many memories. the mathematical equations the formulas thanks for the video. Kind regards from Argentina 👍🙏📻
Thank you, and your welcome.
Excellent video thank you for posting
Thank you, and your welcome.
Thanks for the video, it's hard to retain all that's going on in these radios. I still need to watch these type video's to learn and maybe someday remember what's going on in there.
I hope this video will help. Thank you, and your welcome.
Great explanation, thanks very much!
Thank you, and your welcome.
Wow! Finally! I never understood how superheterodyne works, i could not get around the mistery. This is a very informative video. I get it now, it's not that hard to understand when it is explained like this. I am very gratefull for your video! Thank very, very much!
I'm glad this video helps you understand the superhetrodyne. Thank you, and your welcome.
Well done as always, great teaching, thanks
Thank you, and your welcome.
Merci beaucoup , Qu'elle souvenir .
Thank you, and your welcome.
Excellent! Thank you.
Thank you, and your welcome.
This great video I will save for when I get back to my Sparton model 61, a radio I have not been able to fix. Thank you!
I hope you get the Sparton 67 working. Thank you, and your welcome.
I love your presentations, you explain things very well.
Thank you very much, and your welcome.
Superheterodyne 101. Brilliant video!
Thank you, and your welcome.
Thank you sir, this is very helpful!
Thank you, and your welcome. I'm glad you found this video useful.
I do have FREE eBook that also may find helpful and useful.
The link is in the ABOUT on my TH-cam site.
Here is the information for the eBook. I hope you enjoy and find the information useful.
PASSWORD is allamericanfiveradio
drive.google.com/file/d/1HHmaWYr7UMACfmS4W5uL6PADoem2KlRp/view?usp=sharing
Thank you very much for this excellent explanation. Thank you and best regards.
Thank you, and your welcome.
Nice demonstration. One day, I will understand the superheterodyne working... Thanks.
Thank you, and your welcome.
Una explicacion brillante,excelente canal!!
Thank you, and your welcome.
Good job. Thanks.
Thank you, and your welcome.
Thank you for your good explanation.
Thank you, and your welcome.
thanks for the great explanation
Thank you, and your welcome.
I am adding this video to refererence videos folder, first class explanation! ;)
Thank you, and your welcome.
Звук классный! Прям "ламповый"!
Thank you, and your welcome.
Mahalo Rick. I'm supposed to know all this as a general class ham. Nice brush up, its still fascinating to me.
Thank you, and your welcome.
I have a free ebook you may like.
PASSWORD is allamericanfiveradio
drive.google.com/file/d/1HHmaWYr7UMACfmS4W5uL6PADoem2KlRp/view?usp=sharing
Excellent explanation . Thanks a lot you are really a teacher
Thank you, and your welcome.
5:17 Centralab audio-plate. It is still possible to find old used databooks for those parts but you must really search for them.
Thanks for the information.
Great stuff! Sure wish I had you for a neighbor/elmer to be able to pick your brain! Thank You.
Thank you, and your welcome.
Great explanation & walkthrough, Rick.
Would it be fair to say that the AVC capacitor could supply a signal strength meter (with resistor dividers)?
Yes that would be a good place for a meter. Thank you.
Thanks 👍
It's important to have an over view!
Obrigado
Thank you, and your welcome.
Very nice explanation.
Thank you and, your welcome.
very nice explenation sir thank u ,,
Thank you, and your welcome.
Local oscillator TRACKS incoming station frequency such that the DIFFERENCE between the two signals IS 455KHZ. This is why the variable has 2 section GANGED together. Reason why a certain frequency picked had to DO with component size. RCA patented 455KHz so others had to pick another IF frequency so no royalties would have to BE paid. AVC influence has to BE kept low while peaking IF coils. Pick really faint station, pipe in the IF frequency and peak. LOL The rectifier removes half the carrier envelope so that the audio extraction can take place. There IS so much going on. Always learning. Good video info.
Thank you, and your welcome.
I can smell the circuitry!
Yes! Thanks.
If you've tuned a really old radio without AGC then you'll appreciate what it does.
Thank you, and your welcome.
tks!...
Thank you, and your welcome.
Awesome stuff Rick! FM Next? ;)
Thank you, and your welcome. Good idea.
So in the first tube starting at the bottom you have the cathode which feeds the inductor that feeds the tank circuit. You mentioned this was DC power but the inductor needs AC current if the local oscilator is to function? Also if I understand correctly the screen grid is the transmission signal and the control grid is mixing the LO. What are those other 2 grids that appear to be coupled together on pin 6 of the first tube, they appear to be part of the IF tank circuit?
Hey Ron, we must be amphibious or something. I am currently working on drawings for the oscillator circuit. I had a request from a TH-camr to go through the oscillator circuit in more detail. I'm hoping to be able to upload a video may be this Sunday. I'll try to remember to let you know when I have uploaded a video in a comment on this video.
Just put up this video.
Radio Oscillator Tank Circuit
th-cam.com/video/-Q-gvhErkcY/w-d-xo.html
@@AllAmericanFiveRadio Thank you so much, this is super helpful to build my intuition of how this works. Once I get about 80% on the tube heterodyne I have to learn the solid states.
We have a Harris HT20 and BT35 Transmitters
@@ronpearson1912 Thank you! Good luck with the transmitters!
@@AllAmericanFiveRadio What is your name?
I found an old guitar amp in the trash the other day. It contains a 12AX7a Twin Triode. I have no idea what to do with it. I'll have to re-watch all your tube amp videos!
Ask your questions. How to count tube pins is in appendix of my free ebook, figure A-3 page162'
my email allamericanfiveradio@yahoo.com
can you also prepare one for the all japanese 6 transistor radio?
Thank you.
I'm looking for one.
I have often wondered why it was that automobile radios had a 262khz IF strip. Would you happen to know the answer for that? I'm stumped on it. My 1972 Philco Ford AM only radio has it. Great radio by the way. Very selective and sensitive.
It‘s could to have more sensitivity (more IF gain) better selectivity and better noise réjection from ignition coil and alternator
Sometimes it also has to do with patent infringements.
What is meant by "high que"? (not sure if my spelling is correct).
Q Factor
en.wikipedia.org/wiki/Q_factor
Thanks
All american 5 is a clever design to keep the cost to a mininum in detriment of the security.
Thank you.
Could it be said that the capacitor to ground is a high pass filter sending high frequencies to ground? But you were talking about amplitude of the signal not frequency
Yes it is a high pass filter. But a more accurate term is RF bypass. Because you can have high pass filters in audio, like in your speaker network.
Could you do the same explanation with a transistor based circuit? Great video BTW.
I was thinking about this. Thank you, and your welcome.
Transistor superhetrodyne radio is the same technology as vacuum tube radios, the voltage is different.
I was slightly confused by your statement that "The secondary is hooked up to a diode". I searched from the output of the secondary's coil thru the circuit but did not see a diode anywhere. Then, a little research for the 12AV6 tube data reveals that this tube contains both a triode and 2 separate diodes - internally, the diodes being connected to tube pins 5 & 6. Looking at your diagram, pins 5 & 6 do appear to show as diodes inside the tube. Therein lay my confusion, the IF secondary is hooked to a diode, which is integral to the tube, not a distinct, external component separate from V5. I may be dense but perhaps this will help another so confused. Great video otherwise.
The top wire of the secondary goes to pin#5, that’s the diode. The tube 35W4 is also a diode.
cant see the diode near V5 ?
V5 PIN5
@@AllAmericanFiveRadio cheers AA5R
@@AllAmericanFiveRadio So inside V5 is the diode, when it’s connected thusly? Ah ha… tricky that. I had to look up the tube to research it and find it has two diodes in it. I searched your diagram a long time for a diode on its own. Ha ha
Hi there hope your fine greetz cor
Thank you, and your welcome.
It might be helpful to explain what "High Q" means and what a "tank circuit" is... as those might not be common knowledge in this century.
Oscillators, the Basic Tank Circuit 1
th-cam.com/video/fQ4yRVEzXQA/w-d-xo.html
LC Tank Circuit
th-cam.com/video/8vu9WDjBAho/w-d-xo.html
AM Transmitter Tank Circuit Coil Capacitor Resonance
th-cam.com/video/6TRqNkT5OCk/w-d-xo.html
Radio Oscillator Tank Circuit
th-cam.com/video/-Q-gvhErkcY/w-d-xo.html
Thank you sir@@AllAmericanFiveRadio
That 2nd video seems to be private.@@AllAmericanFiveRadio