I live in Seoul, Korea I have a hobby to collect and repair old radios. The images you uploaded help me understand the radio system. I do not speak English well You speak very slowly The pronunciation is very slow, accurate and kind. You also draw a lot of reference images and upload them with the video It helps a lot of non-English viewers. I always appreciate your good video
WONDERFUL AND SO INSPIRING..IT HELPED ME TREMENDOUSLY IN UNDERTANDING THE CONVERTER STAGE ..SO MUCH TO THE EXTENT OF TURNING MY GRANDMOTHERS DUSTY AND RUSTY DEAF RADIO INTO A SINGING LOUDLY NIGHTINGAIL...IAM VERY GRATEFUL TO YOU...MANY THANKS FOR BEING SO INFORMATIVE AND SUCH A CALM AND INTEGRATED PERSONALITY...HAVE A NICE DAY...
Ho wow thanks. This wiring diagram is from the RCA radio model 9X571. It is a very typical design and many other manufacturers used a close cousin to it.
Also the higher the intermediate frequency, the more audio information can be carried, resulting in higher quality audio. The FCC cleared 455KC, no broadcasting allowed, it's an odd harmonic, and all AM stations are even harmonics which also helps to eliminate other problems.
I was going to talk about the regenerative circuit on my Crosley Pup video but I could not find a wiring diagram for it. However I found my Deforest-Crosley model 51, it is a regenerative circuit and I have the wiring diagram. I have not fired this radio up in years so if I can get it to work I'll do a video on it soon. The regenerative and super regenerative receiver circuits are very similar. The super usually has more tubes and better regenerative controls.
Thanks. The AC bias in your cassette records also uses a tank circuits mostly. If you have a wiring diagram for your recorders, that coil that you identified in your AC bias video, should have an in-phase connection from the coil to the base of the transistor associated with the AC bias circuit, it can be incorporated with the erase head.
Thanks John, I have lots of drawing, photography, and publishing software tools that I used for jobs and my books. Had no idea, when I bought them, how great they would work for TH-cam videos. Regards Rick
Thanks, and I'll keep trying. HO, that's a very good question, and there are a number of reasons. The early radios by different manufactures use many intermediate frequencies, like about 175KC, and notice that this is an odd harmonic. If for some reason there are broadcasts using 175KC it would always interfere with the operation of that radio.
Figures, lol. Good question. The 12SA7 is doing multiple jobs, the tank circuit in the primary of the 1st. I.F. and the tank circuit in L1 & C1 are causing the distortion. L2 is just a coil and it has no capacitor across it to smooth out the wave-form and of courses you can't put one there because you would have another tank circuit. And Thank!
Hi! I’m a rank beginner so please bear with me… from my understanding, the tank circuit causes B vs E to reverse polarity at a frequency controlled by L3. What I don’t understand is your statement that A and E are always in phase. Would that not mean that the cathode loses its negative charge every cycle?
Hi Rick, thanks again for the video If you run to 2 minutes 23 seconds where you discuss R2, is there any significance for connecting the earthy end of R2 to the top of L2? Could R2 have simply been connected to ground, or would that sort of decision been made on the assembly line where it may have been more convenient to solder R2 across the valve holder? Or is there some interaction between the cathode and grid against the resistance / impedance of L2 that I'm missing? Kind Regards. Andy
Rick, As always, a superb video. Detailed technical explanation and use of graphics are extremely well done. I'd rather watch one of your videos than go to the movies...and I love Indiana Jones and Iron Man.:) Regards, John
Thanks for this video, I did learn a lot about radio circuitry electronics, I have a question: What if the Oscillator Frequency is less than the Radio Frequency, what will happen if OL - RF < 0 ?
I have a ecc85 but its pretty simular as the 12at7 And look like it uses the anod instead of the grid Isnt they all based on 12ax7? Its pretty smular name
Some early transistor radios used the ferric iron core antenna as a mixer. Both the signal from the station and the signal from the oscillator were mixed on the ferric iron core.
Your videos are always so well explained and just awesome Rick. Could you do one someday on how later FM tube stereo radios decouples the stereo from the signal? Like a vintage Fisher FM 50B or something like that? Thanks for the awesome vids as always!
Great video - many thanks, I really like your explanation & circuit analysis, please do more. One question if I may (sorry if it sounds so basic) why is the 455KHz was choosen as an IF freq for AM radios?
I live in Seoul, Korea
I have a hobby to collect and repair old radios.
The images you uploaded help me understand the radio system.
I do not speak English well
You speak very slowly
The pronunciation is very slow, accurate and kind.
You also draw a lot of reference images and upload them with the video
It helps a lot of non-English viewers.
I always appreciate your good video
THANKS
WONDERFUL AND SO INSPIRING..IT HELPED ME TREMENDOUSLY IN UNDERTANDING THE CONVERTER STAGE ..SO MUCH TO THE EXTENT OF TURNING MY GRANDMOTHERS DUSTY AND RUSTY DEAF RADIO INTO A SINGING LOUDLY NIGHTINGAIL...IAM VERY GRATEFUL TO YOU...MANY THANKS FOR BEING SO INFORMATIVE AND SUCH A CALM AND INTEGRATED PERSONALITY...HAVE A NICE DAY...
Ho wow thanks.
This wiring diagram is from the RCA radio model 9X571. It is a very typical design and many other manufacturers used a close cousin to it.
Also the higher the intermediate frequency, the more audio information can be carried, resulting in higher quality audio. The FCC cleared 455KC, no broadcasting allowed, it's an odd harmonic, and all AM stations are even harmonics which also helps to eliminate other problems.
I was going to talk about the regenerative circuit on my Crosley Pup video but I could not find a wiring diagram for it. However I found my Deforest-Crosley model 51, it is a regenerative circuit and I have the wiring diagram. I have not fired this radio up in years so if I can get it to work I'll do a video on it soon. The regenerative and super regenerative receiver circuits are very similar. The super usually has more tubes and better regenerative controls.
Thanks.
The AC bias in your cassette records also uses a tank circuits mostly. If you have a wiring diagram for your recorders, that coil that you identified in your AC bias video, should have an in-phase connection from the coil to the base of the transistor associated with the AC bias circuit, it can be incorporated with the erase head.
Thanks John,
I have lots of drawing, photography, and publishing software tools that I used for jobs and my books. Had no idea, when I bought them, how great they would work for TH-cam videos.
Regards
Rick
Thanks, and I'll keep trying.
HO, that's a very good question, and there are a number of reasons. The early radios by different manufactures use many intermediate frequencies, like about 175KC, and notice that this is an odd harmonic. If for some reason there are broadcasts using 175KC it would always interfere with the operation of that radio.
Figures, lol.
Good question. The 12SA7 is doing multiple jobs, the tank circuit in the primary of the 1st. I.F. and the tank circuit in L1 & C1 are causing the distortion. L2 is just a coil and it has no capacitor across it to smooth out the wave-form and of courses you can't put one there because you would have another tank circuit. And Thank!
Ah! A "pentagrid converter" like a 6BE6 and 12BE6 tubes as some of us learned in school!
Great series of vids!
@AndyDaviesByTheSea
Maybe. The only way to find out is to move it. But I don't it would Oscillate as strong.
Hi! I’m a rank beginner so please bear with me… from my understanding, the tank circuit causes B vs E to reverse polarity at a frequency controlled by L3. What I don’t understand is your statement that A and E are always in phase. Would that not mean that the cathode loses its negative charge every cycle?
Oscillators, the Basic Tank Circuit 1
th-cam.com/video/fQ4yRVEzXQA/w-d-xo.html
LC Resonance Oscilloscope Demo
th-cam.com/video/G_RCyDdt2rM/w-d-xo.html
Hi Rick, thanks again for the video If you run to 2 minutes 23 seconds where you discuss R2, is there any significance for connecting the earthy end of R2 to the top of L2?
Could R2 have simply been connected to ground, or would that sort of decision been made on the assembly line where it may have been more convenient to solder R2 across the valve holder?
Or is there some interaction between the cathode and grid against the resistance / impedance of L2 that I'm missing?
Kind Regards. Andy
Thanks mamoynas
And thanks for letting me know about the link. I changed servers and I knew I would not find all my TH-cam links. This one now works.
Thanks sloppyoscar
Yes it is wound so that is it in phase or they reverse the leads to put it in phase. But it must be in phase for positive feedback.
Rick,
As always, a superb video. Detailed technical explanation and use of graphics are extremely well done. I'd rather watch one of your videos than go to the movies...and I love Indiana Jones and Iron Man.:)
Regards,
John
Thanks for this video, I did learn a lot about radio circuitry electronics, I have a question: What if the Oscillator Frequency is less than the Radio Frequency, what will happen if OL - RF < 0 ?
Then the I.F. would be within the band.
More gold from the mine. Which radio's schematic did you use for this example? It looks familiar.
@ElectricSparq
I did not see one listed.
Hi,
Is there a sovtek equivalent for the 12sa7?
Thanks for the video.
Merci for this video.🙂
Thank you, and your welcome.
Just a thought,,, can you use a 455khz crystal, or CF in place of the first IF cans..???
Yes.
I have a ecc85 but its pretty simular as the 12at7
And look like it uses the anod instead of the grid
Isnt they all based on 12ax7?
Its pretty smular name
They both have the same base 9A. Tube information link
nj7p.org/Tubes/SQL/Tube_query.php?Type=12at7
That's a neat and very well-done video!
Is it possible to make a frequency mixer out of chunks of metal like the first transistor was made?
Some early transistor radios used the ferric iron core antenna as a mixer. Both the signal from the station and the signal from the oscillator were mixed on the ferric iron core.
Your videos are always so well explained and just awesome Rick. Could you do one someday on how later FM tube stereo radios decouples the stereo from the signal? Like a vintage Fisher FM 50B or something like that? Thanks for the awesome vids as always!
Hi Rick, I think I found it, nevermind ;) Thanks!
Yes I do have a few videos on FM. But let me know if you need more information.
Hello could you please tell me the value of a local oscillator coil for om? thank you so much
www.tubesandmore.com/products/radio_antique_equipment_parts_0
@@AllAmericanFiveRadio thank you so much!
Great video - many thanks, I really like your explanation & circuit analysis, please do more. One question if I may (sorry if it sounds so basic) why is the 455KHz was choosen as an IF freq for AM radios?
THANKS!
merci bien c est tres interessant voc presentetions
Thanks, and your welcome.
Thanks pozitroniac
nice video... the link is Redirected though...