As always Thank You for making the effort, you explained the signal path in simple terms and kept it so interesting. Been restoring radios for 15 yrs. and still learn so much from your videos.
Here are some videos that may interest you. Oscilloscope signal tracing th-cam.com/video/B44wHjb8jMY/w-d-xo.html Digital PC Oscilloscope Signal Tracing th-cam.com/video/_fHAuzDIgEQ/w-d-xo.html AM Radio Demodulation Oscilloscope Demo th-cam.com/video/pKA0TPdnHg8/w-d-xo.html Superheterodyne AA5 from End to End th-cam.com/video/glakoNN4lwA/w-d-xo.html FM Discriminator Circuit Audio Detection th-cam.com/video/Nef2-VUTwYw/w-d-xo.html
Thanks nottinghamnc In Ham Radio, Morse Code is sent with just the carrier, turning it on and off. You can hear it but it is much like thumping the speaker. If you add a BFO oscillator of a frequency very close to the carriers frequency, and then mix the two you will hear and audio tone every time the carrier is on. This radio oscillator does beat with the radio station but it produces an intermediate frequence I.F. of 455KC. Same principle but for a different purpose.
I have a Westinghouse 602P7 7 transistor radio from 1956, all the electrolytic and wax capacitors have been replaced, the radio now works pretty well. But there is 1 problem, at turn on after being off for a while the radio can take 30-60 seconds before coming to life, any idea what the problem is?
Thanks CameramanLink I can remember transistors being somewhat expensive when I was in High School, because I was buying them one at a time. But for manufacturers they were much less expensive.
I was wondering if you've ever tried using varactors in place of the ganged variable capacitor? I'm ok with a simple varactor VCO, but I'm not sure how to combine two coils in one VCO with a mixer... Any suggestions?
@@andrewferg8737 Hey Andrew Been busy working, if I don't answer an email send it again. Yes I have made some videos on varactors. Varactor sounds like something from Jurassic Park. Varicap, Varactor Diode circuit demo th-cam.com/video/68qOrDl55tc/w-d-xo.html FM Transmitter Varactor Diode Modulator th-cam.com/video/JQGWr2dPe4E/w-d-xo.html Oscillator Varactor Frequency Control circuit demo th-cam.com/video/NOU-bUKpL00/w-d-xo.html I'm still thinking about how to combine two coils in one VCO with a mixer. Rick
Thanks CameramanLink If this radio used NPN transistors the polarity of the battery would be reversed. The frequency mixing is different as for as the medium goes but the physics is the same principle. Yes it takes more transistor than a AA5 tube radio. But transistors are really cheep. Yes they did transistorized it. It is the same AA5 technology modified for the transistors, mainly low impedance transformers, and the small size of all the parts.
Thanks AndyDaviesByTheSea Hey Andy, Thanks for your kind remarks. Hope you sale goes will on ebay. I'll put the "index" idea in my TH-cam Video List. Regards, Rick
I have seen so many radio reciever circuit every circuit has different kind of antenna coil circuit and oscillator circuit it is very difficult to unserstand how and what is happening only know that superhetrodyning is happening but how ?
Hello and greetings from Saudi Arabia. I would thank you for the great videos and the illustration you make it available for your followers. I have Presto K7 Record Cutter Lathe which I couldn’t find any schematic for. I have started the restoration including replacing the tubes and all other components and would ask you to kindly making a video about how to draw a schematic digram correctly for any vintage vacuum tube machine without a schematic available for download and which software you would recommending to use in drawing the schematic to make it available for anyone needs to service or restore the same machine. Thanks.
How to draw up a schematic would make a good video. Good luck with your restoration. Until the video, you might consider downloading my free e-book you may find it useful. The Vacuum Tube Shortwave Radio www.richardmcwhorter.com/vacuumtuberadio/
@thereelmaster Funny you should mention that. I am working on draws now, tube and transistor side by side. I have done a few on how transistor works and or functions. I'll send you some videos.
Hi Richard, another excellent video, a lot of work there! The Marconi 878 radio you commented on is going to be sold on eBay for a poorly friend of mine and I hope you don't mind but I've put a reference to your good work in the advert as I think anyone setting out to restore a valve (or transistor) radio would do well to draw on your experience. Can you upload a video called "index" as there are so many good things to look at in your channel. Well done! Kind Regards ...Andy gw0jxm
Either thinking in conventional current flow, reverse biased transistors, or thinking rf/audio signals would seek going to ground, rather than the next component, really confuses me.
This should help. Impedance and Frequency, Oscilloscope Demo th-cam.com/video/TRSNKwtUy8g/w-d-xo.html Capacitive Reactance and Frequency Demo th-cam.com/video/S5_7gGHxVyQ/w-d-xo.html Capacitors, DC, AC, and Frequencies th-cam.com/video/YfJKNSkz_Lk/w-d-xo.html Superheterodyne Radio, heterodyning frequencies together, how it works th-cam.com/video/5F-iKiltesU/w-d-xo.html The Oscillator Mixer th-cam.com/video/d96vwarHcsg/w-d-xo.html RF Choke Demo th-cam.com/video/M4EOuAa615s/w-d-xo.html LC Resonance Oscilloscope Demo th-cam.com/video/G_RCyDdt2rM/w-d-xo.html Capacitors, DC and AC Current th-cam.com/video/NInt1Ss3vQ4/w-d-xo.html AA5 Radio Signal Flow th-cam.com/video/zknp0FOkPXU/w-d-xo.html
The IF cans are very sharply tuned, very high Q at 455kHz. Mixing the station signal and the oscillator signal together making a 455kHz signal per station one at a time and passes through the IF circuit. If there are two stations close together the one that makes the 455kHz will get through the IF's the other will not. This was the first good station selection circuit and it was cheap.
As always Thank You for making the effort, you explained the signal path in simple terms and kept it so interesting. Been restoring radios for 15 yrs. and still learn so much from your videos.
Many thanks for this very clear video! Trying to align an old AM transistor radio. Now everything is much more clear
I'm glad it helped. Thanks and your welcome.
This is what I have been looking for for a long time. Thank you !
Thanks and your welcome.
Excellent description. I have at least 3 1960s transistor sets that I want to check over when I get the time.
Thanks
Question:
Do you have a video showing tracing the signal on scope for an AM or FM transistor radio ?
Thanks for your great explanation.
Here are some videos that may interest you.
Oscilloscope signal tracing
th-cam.com/video/B44wHjb8jMY/w-d-xo.html
Digital PC Oscilloscope Signal Tracing
th-cam.com/video/_fHAuzDIgEQ/w-d-xo.html
AM Radio Demodulation Oscilloscope Demo
th-cam.com/video/pKA0TPdnHg8/w-d-xo.html
Superheterodyne AA5 from End to End
th-cam.com/video/glakoNN4lwA/w-d-xo.html
FM Discriminator Circuit Audio Detection
th-cam.com/video/Nef2-VUTwYw/w-d-xo.html
Thank you very much for your answer.
I have to admit, was about to stop watching the video at the beginning but I am glad I continued watching. Very good info, thanks for posting the vid.
Thanks nottinghamnc
In Ham Radio, Morse Code is sent with just the carrier, turning it on and off. You can hear it but it is much like thumping the speaker. If you add a BFO oscillator of a frequency very close to the carriers frequency, and then mix the two you will hear and audio tone every time the carrier is on. This radio oscillator does beat with the radio station but it produces an intermediate frequence I.F. of 455KC. Same principle but for a different purpose.
I have a Westinghouse 602P7 7 transistor radio from 1956, all the electrolytic and wax capacitors have been replaced, the radio now works pretty well. But there is 1 problem, at turn on after being off for a while the radio can take 30-60 seconds before coming to life, any idea what the problem is?
This is just a guess, I would think it was the oscillator. It does work so I would just leave it along until it stops working.
@@AllAmericanFiveRadio So you mean the oscillator transistor could be bad?
Thank you Sir!... It's a pleasure to watch your videos
THANKS
Another great lesson following your schematic was great.
Thank you, and your welcome.
Thanks CameramanLink
I can remember transistors being somewhat expensive when I was in High School, because I was buying them one at a time. But for manufacturers they were much less expensive.
I was wondering if you've ever tried using varactors in place of the ganged variable capacitor? I'm ok with a simple varactor VCO, but I'm not sure how to combine two coils in one VCO with a mixer... Any suggestions?
@@andrewferg8737 Hey Andrew
Been busy working, if I don't answer an email send it again.
Yes I have made some videos on varactors. Varactor sounds like something from Jurassic Park.
Varicap, Varactor Diode circuit demo
th-cam.com/video/68qOrDl55tc/w-d-xo.html
FM Transmitter Varactor Diode Modulator
th-cam.com/video/JQGWr2dPe4E/w-d-xo.html
Oscillator Varactor Frequency Control circuit demo
th-cam.com/video/NOU-bUKpL00/w-d-xo.html
I'm still thinking about how to combine two coils in one VCO with a mixer.
Rick
@@andrewferg8737 allamericanfiveradio@yahoo.com
Just wanted to say I enjoy all your videos
Thanks FyberOptic
The only advantage may be that the manufacturer of the radio got a prices cut from the manufacturer of the PNP transistors.
Just wanted to say I enjoy all your videos Darryl
Thanks CameramanLink
If this radio used NPN transistors the polarity of the battery would be reversed. The frequency mixing is different as for as the medium goes but the physics is the same principle. Yes it takes more transistor than a AA5 tube radio. But transistors are really cheep. Yes they did transistorized it. It is the same AA5 technology modified for the transistors, mainly low impedance transformers, and the small size of all the parts.
Thanks AndyDaviesByTheSea
Hey Andy,
Thanks for your kind remarks. Hope you sale goes will on ebay. I'll put the "index" idea in my TH-cam Video List.
Regards,
Rick
Thanks joernone
Hey John,
Your video idea is in the TH-cam video list.
Regards,
Rick
Would there have been any advantage to using all PNP transistors like that?
I have seen so many radio reciever circuit every circuit has different kind of antenna coil circuit and oscillator circuit it is very difficult to unserstand how and what is happening only know that superhetrodyning is happening but how ?
password "allamericanfiveradio'
The Vacuum Tube Shortwave Radio
www.richardmcwhorter.com/vacuumtuberadio/
Rick,
Excellent explanation and great use of graphics. I really enjoyed this vid. Learned a bunch.
Thanks, my friend.
Regards,
John
Excellent description - I love your videos.
Hello and greetings from Saudi Arabia.
I would thank you for the great videos and the illustration you make it available for your followers.
I have Presto K7 Record Cutter Lathe which I couldn’t find any schematic for. I have started the restoration including replacing the tubes and all other components and would ask you to kindly making a video about how to draw a schematic digram correctly for any vintage vacuum tube machine without a schematic available for download and which software you would recommending to use in drawing the schematic to make it available for anyone needs to service or restore the same machine.
Thanks.
How to draw up a schematic would make a good video. Good luck with your restoration. Until the video, you might consider downloading my free e-book you may find it useful.
The Vacuum Tube Shortwave Radio
www.richardmcwhorter.com/vacuumtuberadio/
Brilliant description thanks
Thanks
Very good, thanks for sharing Richard!
Thanks
Such a great video, now I understand it all!
Thanks a lot! Very clearly exposed and interesting.
Thanks
very nicely explained!!! Thank you!
Thanks and your welcome
Ground as positive ?
Interesting ...
thanks for sharing
These are old PNP transistors which have + on their Emitter.
Thank you.
@thereelmaster
Funny you should mention that. I am working on draws now, tube and transistor side by side. I have done a few on how transistor works and or functions. I'll send you some videos.
1
it's good one... thanks, good videos..
THANK YOU!
@thereelmaster
I think I sent you three or four videos. TH-cam is showing one sent. Let me know if you only got one.
@mc68hc000
I uploaded the pictures and you can find the link in the more info of this video.
Hi Richard, another excellent video, a lot of work there!
The Marconi 878 radio you commented on is going to be sold on eBay for a poorly friend of mine and I hope you don't mind but I've put a reference to your good work in the advert as I think anyone setting out to restore a valve (or transistor) radio would do well to draw on your experience.
Can you upload a video called "index" as there are so many good things to look at in your channel.
Well done!
Kind Regards ...Andy gw0jxm
Either thinking in conventional current flow, reverse biased transistors, or thinking rf/audio signals would seek going to ground, rather than the next component, really confuses me.
This should help.
Impedance and Frequency, Oscilloscope Demo
th-cam.com/video/TRSNKwtUy8g/w-d-xo.html
Capacitive Reactance and Frequency Demo
th-cam.com/video/S5_7gGHxVyQ/w-d-xo.html
Capacitors, DC, AC, and Frequencies
th-cam.com/video/YfJKNSkz_Lk/w-d-xo.html
Superheterodyne Radio, heterodyning frequencies together, how it works
th-cam.com/video/5F-iKiltesU/w-d-xo.html
The Oscillator Mixer
th-cam.com/video/d96vwarHcsg/w-d-xo.html
RF Choke Demo
th-cam.com/video/M4EOuAa615s/w-d-xo.html
LC Resonance Oscilloscope Demo
th-cam.com/video/G_RCyDdt2rM/w-d-xo.html
Capacitors, DC and AC Current
th-cam.com/video/NInt1Ss3vQ4/w-d-xo.html
AA5 Radio Signal Flow
th-cam.com/video/zknp0FOkPXU/w-d-xo.html
Why do you need to add the if signal? Why don’t you just amplify the received signal ?
The IF cans are very sharply tuned, very high Q at 455kHz. Mixing the station signal and the oscillator signal together making a 455kHz signal per station one at a time and passes through the IF circuit. If there are two stations close together the one that makes the 455kHz will get through the IF's the other will not. This was the first good station selection circuit and it was cheap.
AllAmericanFiveRadio thank you that makes a lot of sense
another great one ty.
say your rely good at making videos on how vacume tubes work, can ya make a video on how a transitor works? thanks
Thanks barn5923
Thanks lawnmowerrecycler
Thanks mondays89
Thanks dr34mc0d3r
👍👍👍
Thanks
Cool..
Thanks and your welcome.
Thankyou
Thanks
Thanks mc68hc000
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