As my father said: the most hard and complex devices are Radios compared to TVs or anything else (in the old era) My father has some experience on Radio/Tv repair but he is no longer remembering most of tricks
Very nice explanation of these tuners, which work better than some of the ones we have in low-priced products today. My grandmother built super-het tuners for the U.S. Military in the 1950's/60's and tried to teach me how they worked, but I forgot virtually all of it by the time I reached adulthood as I was more interested in computers ;). Some parts of Europe have stopped FM analog broadcasts entirely, so analog radio receivers are becoming more and more obsolete, as analog TV tuners already are. AM survives, but more and more shortwave is becoming digital as well as it can use bandwidth so much more efficiently. This is generally a good thing, but with digital transmission you cannot simply build an electrical device that will receive intelligible signals; you also need digital "demodulation" to convert the signal to a useful form. There should always be a place for simple AM-modulated shortwave carrying voice or Morse as that remains useful even in an apocalypse ;). Most of the people that knew Morse are dead, though.
Yes, I regret that you needed only 1 active component to receive AM but you need tens of thousands to receive DAB. I doubt there is a single person who fully understands how to build a digital radio from the ground up.
No FM anymore in norway, only on small local radio stations. So now car radios and old radiocabinets is not working, and millions of radios tossed in the garbage. Also, batterylife on dab sucks :(
There are plenty of amateur radio operators worldwide that know Morse code. Under poor signal reception conditions it is much easier to communicate in Morse than voice. Will probably never die out entirely.
Thanks for the nice explanation of how this receiver works! You really hit the sweet spot for me this time, where I know just enough to follow you, but not so much that there is little left to learn.
DiodeGoneWild, I love your videos and have learned a lot about electronics from your videos. Wishing you a long and healthy life, greetings from the United Kingdom.
In the model number of the Soviet receivers and other general purpose electronic the first digit indicates the complexity class of the receiver, which includes the minimum set of functions of the device, sensitivity and range of sound frequencies produced by the speaker. There are 4 classes in total: 0,1,2,3. Electronics that do not meet the requirements of this standard received a classification of 4,5,6 (as a rule, due to some worse parameters). The receiver "sokol" of the 3rd class model 08 is so called.
Thank you for the long Video. Gott mine today sheap from German Ebay, must be the Western Export Model up to 104 Mgz. It works ok on Fm and now i hesitate to tinker on it seeing how packed its inside.
Amazing video. The superhet and the filtering are still a bit of a haze to me, but this shed a lot of light. I only recently got into radio tech (even got myself an old VEF).
You always learn something here. I knew how a superhet works, but didn't know that sokol meant falcon in Russian although I know some people with Sokol as last name.
This video is actually great educational content. You explain things not just theoretically, but practically. Your other videos are equally good. Your channel deserves much more views.
and now travel back in time to the designers of this radio and tell them we now have software defined radios .. they would have burned you at the stake 😂
They designed for the minimal amount of active components. If you told them you had a radio using a million transistors just in the RF section, and another 5 million to recover the audio out of sampling the input directly at frequency, and then another half million to make the display of frequency and the audio output amplifier, they would consider you crazy. Then tell them this all fits, along with all the support components, into a volume smaller than the tuning capacitor alone, and they would have brought out the rubber suits for you.
Than you will Cause Grandfather and Butterfly paradoxical effect letting all previous scientist to do nothing so no SHDR , no PLL , no Vco etc and that all end up with No such thing as SDR . 😂😂
Just for clarification: The frequency response of an ideal LC filter is inversely proportional to the frequency difference from resonance, but real LC filters have a round, wider, not infinitely high peak at resonance. The bandwidth is usually measured between points where the voltage drops to -3 dB below peak (1/√2̅ of max amplitude) or -20 dB below peak (1/10 of max amplitude).
@@omniyambot9876 I don’t really know. I was taught this at university but literature and/or online courses should cover this too. You can calculate LC filters by hand but a better way is to use an advanced SPICE program’s frequency analysis feature. My school uses LTspice, which is likely the best free option. It takes some time to get used to the early 2000s-style UI and controls, though - better read an online guide.
For a second i thought i was watching Shango066, but no sarcasm :) That radio looks well made, i also like the different design of components. Hand drawn pcb tracks, some people don't like them but they work fine :-D Some schematic diagrams are all over the place. Etch-a-sketch lol. I am used to a block of parts with inputs and outputs, no mad wandering off for no reason. Your cat would not make a messy diagram, unless it was made of string and a fake mouse :-D
@@westelaudio943 yes they are good, shame the company is dead. Philips have made some odd stuff, they once had a habit of using an audio stage for other functions, the problem was if that bit failed, everything stopped working. A very tight ass company years back, silly design.
Awesome video!! In 46 minutes you have explained a whole radio from the antenna to the speaker in the clearest way possible! Just for curiosity, are you a teacher or is this just your passion?
Most likely 9V (Вольт) socket has center positive. Most Soviet radios had this arrangement. The old school transistors you are referring to most likely germanium (германиевые) transistors. Soviet made BM paper capacitors were very stable and could last tens of years. K50-6 soviet electrolitic capacitors unfortunately were notorious for leaks, though it is 1980..Capacitor you were referring to was a part of so called ARU (АРУ Автоматическая Регулировка Усиления) system which controlled automatically RF gain. On schematics transistors ГТ404Б (GT404B) can be replaced with 2SD127A, AC141 Спасибо за отличное видео.
Hi diode gone wild if you are reading this comment. Please next video explain a Solid state Geiger counter.... Using photodiode ..... Very Interesting. It works
In the US we had FM radio in a lower band before moving to the modern 88-108 MHz. Except this was a _long_ time ago and the old band was discontinued in 1949 so it was never popular.
Fantastic video as usually! I was thinking to a solution to convert it to modern fm reception without modify the original circuits (but you probably already now this solution...), you can use the local oscillator, feed it in a frequency to voltage converter and then feed this dc voltage in a small varicap radio reciver, and then inject the output in the audio amplifier, i saw this solution used in old vacuum tube radio restoration. Actually, there are already made kit for this. I was trying to do it on an old Geloso reciver from 1934, but i was trying to use scrap parts, like for the fm reciver there are those small Chinese poket radio with scan button instead of a tuning knob, feeding the varicap with a dc voltage from a potentiometer allows you to use it as a tuning knob (cheap radio and cheap hack!), meaby you already have this tipe of radio in your collection 😁 Would be nice to see a video with your idea and solution to make it work!
Ahoj, mam sokola taky.......kdysi to byl darek od taty k vanocum.....hodne me bavilo....pak upadlo v zapomneni a zmizelo nekde na pude....nedavno ho tata nasel a dal mi ho....momentalne se pokousim preladit ho na CCIR.....zmenou kapacit v tabulce na schematu na hodnoty pro ccir pasmo....
OIRT wasn't "old" or "worse". Yes, it's no longer in use, but that's because in mid 90's there was more cheap sender equipment for CCIR (87.5 to 108) OIRT's lower frequency was better suited for the Soviet union's geography, and if I remember correctly, the bandwidth was better used, i.e. not the whole 100kHz as in CCIR, but ca. 38kHz + a gap - that's what you need for stereo transmission. And there was stereo for it since mid 70's.
Also lower frequency allowed use of less capable transistors, where you did not need to have a very thin base region, because you did not need to go so high in frequency, so the poorer spec transistors could be used, not having as high a transition frequency.
@@SeanBZA and now your "theory" falls apart by two simple facts - first being that all transistors that were used for those FM radios were capable of waaay higher frequencies than 108MHz, usually up to 300+ and it was possible to modify any FM radio to listen to airplane/tower communications ezpz.
You're right, with same transmitter output power you can get better reception at higher distance in lower FM band. Also stereo signal encoding system was more stable at lower signal levels and actually less noisy. In general it's almost the same situation as in why USSR chose SECAM over Never The Same Color as color TV system - SECAM worked better in long distance/ low signal situations.
@@shadowflash705 Yes ,but the design is very old, when high frequency response was kind of hard, and to get those with a good high frequency response you had to take a batch of transistors, put them in a test jig, and see which ones worked good at 70MHz, and set those aside, while the rest with poorer response went back in as the regular one, the high frequency ones being labelled differently.
16:58 Timestamp Any details about that pink transistor tester? How can it test the leakage of caps‘s? was under the impression that transistor testers didn’t put out anywhere near enough voltage to test electrolytic leakage. Any clarification would be much appreciated. Thank you for your time
It's this: danyk.cz/test_tr_en.html It just amplifies the leakage current using one transistor and indicates using a super bright red led. It also has a green led with no amplification transistor to indicate a high current.
Staré východní FM pásmo není opuštěné, nastěhovalo se tam vysílání bezdrátového místnbího rozhlasu. Jesli máš v okolí nějaký provozovaný bezdrátový rozhlas, můžeš ho zkusit na tom rádiu chytit.
There are some newer Chinese radios which can pick up the OIRT band. BTW OIRT stands for Organisation Internationale de Radiodiffusion et de Télévision. It was one of the predecessors of the European Broadcast Union.
Nice radio and nice explanation! Wondering if the voltage regulator has gone open circuit, according to the 4.2-ish volts voltage and the low current, you might be able to replace it with a TP4056. in that case, the TP4056 will work in the constant voltage mode, providing a regulated 4.2V voltage. there is also TP4057, which is a smaller, less capable (lower rated current) version of the 4056. You can botch it on the regulated voltage rail.
@@Tegelane5 Hmmm Nice idea. although the diode's Vf may vary significantly with changing temperature and forward current, potentially making the regulator output inaccurate/ unstable.
конденсаторы типа К50-6 и К50-16 надо менять сразу даже без проверки. почти всегда на этом ремонт заканчивается и устройство начинает исправно работать
@@DiodeGoneWild He is like the friendly helper of vintage TVs and radios, he wants people to learn, I think he would rather invite you over for a coffee than shoot!
Probably can be tuned to the modern bands with just a turn or two removed from the input and LO inductors, or lower value padding capacitors for them. Then would cover the band, though simply taking the input filter and making it resonant ant the higher frequency without touching the LO would work, covering part of the band. Then getting AFC to work would just mean turning the 2 discriminator diodes around, to change the sense of the AFC voltage to suit the image reception.
This kind of capacitor-tuned receivers are typically "retuned" by replacing (or even ripping out) certain capacitors. Messing with the coils is usually a bad idea, often an indicator of something else done wrong. We had lots of OIRT receivers here in Poland too, with transmitters shut down in 1999, so all kinds of hobbyists and professionals got their hands on these.
@@k4be. In most FM tuners, to convert them from CCIR to OIRT, you just need to add parallel capacitors with the tuning capacitor. Converting one from OIRT to CCIR is much more difficult because the CCIR band is much wider. If you change some capacitors only, it usually would not cover the whole band. In order to cover the whole band, you should alter the number of turns on the coils. Also quite often there is a bandpass filter on the antenna input to reduce mirror reception, that should also be re-tuned in order to get reasonable sensitivity. I have multiple examples of the same model boomboxes, both with OIRT and CCIR band, and the coils are different out of the factory.
@@mrnmrn1 From my experience, it typically turns out well when just removing the capacitance. Less parallel capacitance means wider tuning, as the ratio of lowest/highest capacitance value is bigger. Antenna filter is even simpler as it's not tunable so should just be set to the band's central frequency. Of course it is possible there are some receivers with a different design. I'm talking about a typical central-european radio. A good serviceman with correct equipment should achieve good results with any receiver that isn't faulty. The "re-tuning" guides for exact boards/models though made the work significantly faster, and feasible for unexperienced people with no real measurement equipment (using broadcast stations for determining tuning range and tuning input filter for signal strength). The guide linked below just says to cut out C1, C9, C13 and then fine-tune all circuits. zsel.pl/przestrojenie-gfe-105.pdf
@@k4be. It works good for tuners designed for CCIR and than modified to OIRT. Sokol was designed to OIRT, so sometimes the coil modification is needed.
Those weird ones are the old Hungarian symbols for electronic components. Later they were replaced to international ones. That schematic is made by Gelka (short for Gépipari Elektromos Karbantartó Vállalat, aka Mechanical Electrical Maintenance Company), a socialist company owned by the government. In the original form it existed from 1960 to 1993.
Can someone explain to me how I was able to receive 450MHz analog cellphone conversations with my OIRT band Panasonic RX-1650 mono boombox? They showed up around 69MHz on the dial, dozens of cellphone signals very close to each other, but the AFC was able to jump across them accurately, it needed a very faint and careful touch of the tuning knob. 450MHz is very far away from the FM band, maybe I was receiving some inter-tower link which used a lower frequency? There was a continuous weird buzz on the channels which were in standby, so I guess these signals were coming from the tower, and not from the phones, because a phone would not transmit continuously in standby. I still have a cassette with recorded conversations, from the late '90s. It even contains someone listening to his voicemail :-). Usually only one party was audible, the other was very low volume or completely inaudible.
According to Yankee people the superhet was invented by E.H.Armstrong, but Frenchies claimed it's L. Lévy...Anyway the principle is a trivial mathematic formula: if you generate the mathematical product of two cosine waves (that is called a mixer), say cos( w1t) and cos(w2t),you should have learned at school that the equivalent result is = 1/2( cos (w1+w2)t + cos (w1-w2) where w1 is the local oscillator frequency and w2 is the wanted signal frequency.
@@DiodeGoneWild did you recently open up that channel. If I recall there were alot of private videos. You should be glowing haha. You could make a wild sci-fi movie. A silent one except for all the evil noises electricity can make.
I HAVE A QUESTION ON RUSSIAN RADIO SCHEMATICS. On most radio schematics the ground symbols shows that the chassis is negative but on Russian schematics the symbols are showing positive or b plus chassis. Is this true?
![Kodak Black - Versatile 4 [Official Video]](http://i.ytimg.com/vi/VcP_1Ua__vY/mqdefault.jpg)
I love your "bloody-long" videos. Thanks!
47 minute long video? Consider me satisfied!
samee
Thank you for explaining the working of ratio detector circuit. I think I finally go the hang of it. That's bloody amazing ;)
As my father said: the most hard and complex devices are Radios compared to TVs or anything else (in the old era)
My father has some experience on Radio/Tv repair but he is no longer remembering most of tricks
🫂
Thanks for a great explanation of the ratio detector - I finally understand it after all these years.... yay!
8:44 finally! A hungarian schematic on this channel!
Shango066 used the same GELKA schematic in Los Angeles to repair his Sokol 308. Kicsi a világ! :-)
Very nice explanation of these tuners, which work better than some of the ones we have in low-priced products today. My grandmother built super-het tuners for the U.S. Military in the 1950's/60's and tried to teach me how they worked, but I forgot virtually all of it by the time I reached adulthood as I was more interested in computers ;).
Some parts of Europe have stopped FM analog broadcasts entirely, so analog radio receivers are becoming more and more obsolete, as analog TV tuners already are. AM survives, but more and more shortwave is becoming digital as well as it can use bandwidth so much more efficiently.
This is generally a good thing, but with digital transmission you cannot simply build an electrical device that will receive intelligible signals; you also need digital "demodulation" to convert the signal to a useful form. There should always be a place for simple AM-modulated shortwave carrying voice or Morse as that remains useful even in an apocalypse ;). Most of the people that knew Morse are dead, though.
Yes, I regret that you needed only 1 active component to receive AM but you need tens of thousands to receive DAB. I doubt there is a single person who fully understands how to build a digital radio from the ground up.
No FM anymore in norway, only on small local radio stations.
So now car radios and old radiocabinets is not working, and millions of radios tossed in the garbage.
Also, batterylife on dab sucks :(
There are plenty of amateur radio operators worldwide that know Morse code. Under poor signal reception conditions it is much easier to communicate in Morse than voice. Will probably never die out entirely.
@@gordonwedman3179Thanks. 👍 I'm one of them.
Thanks for the nice explanation of how this receiver works! You really hit the sweet spot for me this time, where I know just enough to follow you, but not so much that there is little left to learn.
the best explanation ratio detector i ever seen in whole internet !! he is a genius
DiodeGoneWild, I love your videos and have learned a lot about electronics from your videos. Wishing you a long and healthy life, greetings from the United Kingdom.
Great video, thank you. Já jsem z Pardubic ale žijí v USA , škoda že my tady nemáme takové staré radio. Děkuji moc, hrozně moc jsem se naučil on tebe.
Again a great video, I always have a problem remembering the superhet, but I bet this time it's going to stick.
Thanks a lot!
18:08 The sadness in his voice when it stopped working
In the model number of the Soviet receivers and other general purpose electronic the first digit indicates the complexity class of the receiver, which includes the minimum set of functions of the device, sensitivity and range of sound frequencies produced by the speaker. There are 4 classes in total: 0,1,2,3. Electronics that do not meet the requirements of this standard received a classification of 4,5,6 (as a rule, due to some worse parameters). The receiver "sokol" of the 3rd class model 08 is so called.
This is the best explanation of a ratio detector i have ever heard.
Thank you for the long Video. Gott mine today sheap from German Ebay, must be the Western Export Model up to 104 Mgz. It works ok on Fm and now i hesitate to tinker on it seeing how packed its inside.
Thanks for the great explanation! I finally understood how a ratio detector works
Very interesting video with the old soviet-radio! Thank you DGW! God bless you!!! 👏☺️
Awesome explaining - thank you very much! (no minutes are to much)
Amazing video. The superhet and the filtering are still a bit of a haze to me, but this shed a lot of light. I only recently got into radio tech (even got myself an old VEF).
VEFs are really hot receivers, only bad that there are less and less AM transmitters in Europe.
@@teslakovalaborator I wouldn't mind having one myself.
Classic collection of the soviet radio issues.
Wow... I found your another channel...... Full of interesting & amazing videos 😍😍
You always learn something here. I knew how a superhet works, but didn't know that sokol meant falcon in Russian although I know some people with Sokol as last name.
To me, Sokol always meant "spacesuit" ;)
This video is actually great educational content. You explain things not just theoretically, but practically. Your other videos are equally good. Your channel deserves much more views.
Very nicely explained as always, thank you!
I held this radio in my hands in 1998 year when I was 15.
Looking forward to the second part!
I recently bought a new new small radio, Retekess R115, and that does cover the OIRT FM band, as well as the 76MHz FM band that's used in Japan.
A bloody great bloody long video and a excellent tutorial...cheers.
Love Soviet erra engineering .
and now travel back in time to the designers of this radio and tell them we now have software defined radios .. they would have burned you at the stake 😂
They designed for the minimal amount of active components. If you told them you had a radio using a million transistors just in the RF section, and another 5 million to recover the audio out of sampling the input directly at frequency, and then another half million to make the display of frequency and the audio output amplifier, they would consider you crazy. Then tell them this all fits, along with all the support components, into a volume smaller than the tuning capacitor alone, and they would have brought out the rubber suits for you.
And the SDR for all that extra technology, don't work so well..
Than you will Cause Grandfather and Butterfly paradoxical effect letting all previous scientist to do nothing so no SHDR , no PLL , no Vco etc and that all end up with No such thing as SDR .
😂😂
Just for clarification: The frequency response of an ideal LC filter is inversely proportional to the frequency difference from resonance, but real LC filters have a round, wider, not infinitely high peak at resonance. The bandwidth is usually measured between points where the voltage drops to -3 dB below peak (1/√2̅ of max amplitude) or -20 dB below peak (1/10 of max amplitude).
thank for reminding me I'm stupid. Where do I start to understand these?
@@omniyambot9876 I don’t really know. I was taught this at university but literature and/or online courses should cover this too. You can calculate LC filters by hand but a better way is to use an advanced SPICE program’s frequency analysis feature. My school uses LTspice, which is likely the best free option. It takes some time to get used to the early 2000s-style UI and controls, though - better read an online guide.
For a second i thought i was watching Shango066, but no sarcasm :)
That radio looks well made, i also like the different design of components.
Hand drawn pcb tracks, some people don't like them but they work fine :-D
Some schematic diagrams are all over the place. Etch-a-sketch lol.
I am used to a block of parts with inputs and outputs, no mad wandering off for no reason.
Your cat would not make a messy diagram, unless it was made of string and a fake mouse :-D
I bet you like Grundigs, LOL!
@@westelaudio943 yes they are good, shame the company is dead.
Philips have made some odd stuff, they once had a habit of using an audio stage for other functions, the problem was if that bit failed, everything stopped working.
A very tight ass company years back, silly design.
At 10'48" your radio received a station from my country, Romania. :)
Awesome video!! In 46 minutes you have explained a whole radio from the antenna to the speaker in the clearest way possible!
Just for curiosity, are you a teacher or is this just your passion?
Great video, interested to see the regulator it's some sort of linear regulator i guess , second watch has me loving your explanation.
Very informative video, old analog radios are really black magic
Most likely 9V (Вольт) socket has center positive. Most Soviet radios had this arrangement. The old school transistors you are referring to most likely germanium (германиевые) transistors. Soviet made BM paper capacitors were very stable and could last tens of years. K50-6 soviet electrolitic capacitors unfortunately were notorious for leaks, though it is 1980..Capacitor you were referring to was a part of so called ARU (АРУ Автоматическая Регулировка Усиления) system which controlled automatically RF gain. On schematics transistors ГТ404Б (GT404B) can be replaced with 2SD127A, AC141 Спасибо за отличное видео.
I don't have time to watch this yet but I am very much looking forward to it, hahah. After that Soviet TV I want to see all the Soviet things!
Hi diode gone wild if you are reading this comment.
Please next video explain a Solid state Geiger counter.... Using photodiode ..... Very Interesting. It works
Best video on this subject.
I had absolutely the same radio at home in Prizren...Kosovo and Metohija.....
10:46 that is romanian post radio. Interesting. 😅
Nice explained.
As always very good and lot of animals...
Nice lesson, thank you!
Nice and detailed! 👏 👏 👍
Superbe explanation
In the US we had FM radio in a lower band before moving to the modern 88-108 MHz. Except this was a _long_ time ago and the old band was discontinued in 1949 so it was never popular.
Dan
where's the hotel vacation video ?😂
what switches and lamps.
it's time for vacation 🎉🎉
very well explained! thank you!!
you are doing the best job, thanks!
Fantastic video as usually!
I was thinking to a solution to convert it to modern fm reception without modify the original circuits (but you probably already now this solution...), you can use the local oscillator, feed it in a frequency to voltage converter and then feed this dc voltage in a small varicap radio reciver, and then inject the output in the audio amplifier, i saw this solution used in old vacuum tube radio restoration.
Actually, there are already made kit for this.
I was trying to do it on an old Geloso reciver from 1934, but i was trying to use scrap parts, like for the fm reciver there are those small Chinese poket radio with scan button instead of a tuning knob, feeding the varicap with a dc voltage from a potentiometer allows you to use it as a tuning knob (cheap radio and cheap hack!), meaby you already have this tipe of radio in your collection 😁
Would be nice to see a video with your idea and solution to make it work!
Ahoj, mam sokola taky.......kdysi to byl darek od taty k vanocum.....hodne me bavilo....pak upadlo v zapomneni a zmizelo nekde na pude....nedavno ho tata nasel a dal mi ho....momentalne se pokousim preladit ho na CCIR.....zmenou kapacit v tabulce na schematu na hodnoty pro ccir pasmo....
OIRT wasn't "old" or "worse". Yes, it's no longer in use, but that's because in mid 90's there was more cheap sender equipment for CCIR (87.5 to 108)
OIRT's lower frequency was better suited for the Soviet union's geography, and if I remember correctly, the bandwidth was better used, i.e. not the whole 100kHz as in CCIR, but ca. 38kHz + a gap - that's what you need for stereo transmission.
And there was stereo for it since mid 70's.
In my country the Republic of Belarus OIRT 65,9-74MHz is working. Three radiostation.😄
Also lower frequency allowed use of less capable transistors, where you did not need to have a very thin base region, because you did not need to go so high in frequency, so the poorer spec transistors could be used, not having as high a transition frequency.
@@SeanBZA and now your "theory" falls apart by two simple facts - first being that all transistors that were used for those FM radios were capable of waaay higher frequencies than 108MHz, usually up to 300+ and it was possible to modify any FM radio to listen to airplane/tower communications ezpz.
You're right, with same transmitter output power you can get better reception at higher distance in lower FM band. Also stereo signal encoding system was more stable at lower signal levels and actually less noisy. In general it's almost the same situation as in why USSR chose SECAM over Never The Same Color as color TV system - SECAM worked better in long distance/ low signal situations.
@@shadowflash705 Yes ,but the design is very old, when high frequency response was kind of hard, and to get those with a good high frequency response you had to take a batch of transistors, put them in a test jig, and see which ones worked good at 70MHz, and set those aside, while the rest with poorer response went back in as the regular one, the high frequency ones being labelled differently.
I love your cat's comments! Hello kitty! You are very pretty / handsome!
Great video!
I've been subscribed but I missed this video somehow. I noticed your video like 10 spots down in the sidebar after watching Altium Designer's channel.
16:58 Timestamp
Any details about that pink transistor tester? How can it test the leakage of caps‘s?
was under the impression that transistor testers didn’t put out anywhere near enough voltage to test electrolytic leakage.
Any clarification would be much appreciated.
Thank you for your time
It's this: danyk.cz/test_tr_en.html It just amplifies the leakage current using one transistor and indicates using a super bright red led. It also has a green led with no amplification transistor to indicate a high current.
Awesome ussr quality eletronics.
Staré východní FM pásmo není opuštěné, nastěhovalo se tam vysílání bezdrátového místnbího rozhlasu. Jesli máš v okolí nějaký provozovaný bezdrátový rozhlas, můžeš ho zkusit na tom rádiu chytit.
Aha, to jsem nevěděl :) někdy to musím zkusit. Ale asi to bude vysílat jen první středu v měsíci, když to testujou :D.
There are some newer Chinese radios which can pick up the OIRT band. BTW OIRT stands for Organisation Internationale de Radiodiffusion et de Télévision. It was one of the predecessors of the European Broadcast Union.
I have a new Chinese radio that can pick-up the OIRT band. Although AFAiK the OIRT band was never used for broadcast FM stations in China.
And of course the cat is my favorite
Finally Radio ...thank you.
sokol where the best radios. i still have a sokol 403 that still works without any modification ar replaced component
Nicely Explained 👌👋
09:56 it started fixing itself!😂
20:50 that's what I was going to ask but your cat asked just after
Much appreciated 👍
Nice radio and nice explanation!
Wondering if the voltage regulator has gone open circuit, according to the 4.2-ish volts voltage and the low current, you might be able to replace it with a TP4056. in that case, the TP4056 will work in the constant voltage mode, providing a regulated 4.2V voltage.
there is also TP4057, which is a smaller, less capable (lower rated current) version of the 4056. You can botch it on the regulated voltage rail.
Might aswell use LM7805 and a diode. Diode makes about 0,5..0,7 voltage drop so it would give out 4,3...4,5 volts. (LM7805 is easier to obtain)
@@Tegelane5 Hmmm Nice idea. although the diode's Vf may vary significantly with changing temperature and forward current, potentially making the regulator output inaccurate/ unstable.
That foreign station sounded like Romanian folk music
First, I though it was Hungarian, but I couldn't identify any word. It sounded good, anyway. Our folk music is similar.
If you reverse the diodes the AFC should work for mirrorfrequencies, right?
Greetings from the Netherlands.
Yes.
конденсаторы типа К50-6 и К50-16 надо менять сразу даже без проверки. почти всегда на этом ремонт заканчивается и устройство начинает исправно работать
Thanks for the explanation. I am looking for a diagram to make a metal detector
Damm my guy teach me better than my teacher at school
Thanks for ur information .i hope u make video how to convert modified wave to pure sine wave we need it so much please
Is there a second part? I cant find it!!
Keep making RF videos
I'm looking at the pcb and thinking how they made it. Hand drawn?
I think you entered Shango066 territories! He should really see this, he loves that Russian stuff
I hope he doesn't shoot at trespassers ;)
@@DiodeGoneWild He is like the friendly helper of vintage TVs and radios, he wants people to learn, I think he would rather invite you over for a coffee than shoot!
Brother, could you please explain what is different between CCCV SM battery charger and a normal SMPS. Thanks.
Devices are so scared of your huge soldering gun that they try to fix themselves.
Probably can be tuned to the modern bands with just a turn or two removed from the input and LO inductors, or lower value padding capacitors for them. Then would cover the band, though simply taking the input filter and making it resonant ant the higher frequency without touching the LO would work, covering part of the band. Then getting AFC to work would just mean turning the 2 discriminator diodes around, to change the sense of the AFC voltage to suit the image reception.
This kind of capacitor-tuned receivers are typically "retuned" by replacing (or even ripping out) certain capacitors. Messing with the coils is usually a bad idea, often an indicator of something else done wrong. We had lots of OIRT receivers here in Poland too, with transmitters shut down in 1999, so all kinds of hobbyists and professionals got their hands on these.
One of the schematics appeared to show what the component differences are between the two bands so it should be easy to figure out.
@@k4be. In most FM tuners, to convert them from CCIR to OIRT, you just need to add parallel capacitors with the tuning capacitor. Converting one from OIRT to CCIR is much more difficult because the CCIR band is much wider. If you change some capacitors only, it usually would not cover the whole band. In order to cover the whole band, you should alter the number of turns on the coils. Also quite often there is a bandpass filter on the antenna input to reduce mirror reception, that should also be re-tuned in order to get reasonable sensitivity. I have multiple examples of the same model boomboxes, both with OIRT and CCIR band, and the coils are different out of the factory.
@@mrnmrn1 From my experience, it typically turns out well when just removing the capacitance. Less parallel capacitance means wider tuning, as the ratio of lowest/highest capacitance value is bigger. Antenna filter is even simpler as it's not tunable so should just be set to the band's central frequency.
Of course it is possible there are some receivers with a different design. I'm talking about a typical central-european radio. A good serviceman with correct equipment should achieve good results with any receiver that isn't faulty. The "re-tuning" guides for exact boards/models though made the work significantly faster, and feasible for unexperienced people with no real measurement equipment (using broadcast stations for determining tuning range and tuning input filter for signal strength). The guide linked below just says to cut out C1, C9, C13 and then fine-tune all circuits.
zsel.pl/przestrojenie-gfe-105.pdf
@@k4be. It works good for tuners designed for CCIR and than modified to OIRT. Sokol was designed to OIRT, so sometimes the coil modification is needed.
I wish I were smart enough to have followed along with this video... STAY IN SCHOOL, KIDS!
Hezké
Did you mange to repair it? I couldnt find the next video.
Hi please can you make video about your lab bench power supply or make one of those please can you do that?
Those weird ones are the old Hungarian symbols for electronic components. Later they were replaced to international ones.
That schematic is made by Gelka (short for Gépipari Elektromos Karbantartó Vállalat, aka Mechanical Electrical Maintenance Company), a socialist company owned by the government.
In the original form it existed from 1960 to 1993.
I had one of this radio, but the status of it was way unrepairable, so, sadly it got reused for salvaging components from it. 😐
Can someone explain to me how I was able to receive 450MHz analog cellphone conversations with my OIRT band Panasonic RX-1650 mono boombox? They showed up around 69MHz on the dial, dozens of cellphone signals very close to each other, but the AFC was able to jump across them accurately, it needed a very faint and careful touch of the tuning knob. 450MHz is very far away from the FM band, maybe I was receiving some inter-tower link which used a lower frequency? There was a continuous weird buzz on the channels which were in standby, so I guess these signals were coming from the tower, and not from the phones, because a phone would not transmit continuously in standby. I still have a cassette with recorded conversations, from the late '90s. It even contains someone listening to his voicemail :-). Usually only one party was audible, the other was very low volume or completely inaudible.
Try listening to SW in the night, u should receive more stations.
42:10 than you need another tool Spectrum Analyser
And I like if you built this yourself
Center positive / negative not mentioned.
Wonderful, does anyone know who discovered this differential mixing effect?
According to Yankee people the superhet was invented by E.H.Armstrong, but Frenchies claimed it's L. Lévy...Anyway the principle is a trivial mathematic formula: if you generate the mathematical product of two cosine waves (that is called a mixer), say cos( w1t) and cos(w2t),you should have learned at school that the equivalent result is = 1/2( cos (w1+w2)t + cos (w1-w2) where w1 is the local oscillator frequency and w2 is the wanted signal frequency.
Advanced analogics black magic lesson
Why is the IF 10.7mhz and not a round number like 10mhz?
FM band is 87,5-108 MHz, so 20,5MHz wide. With 10,7MHz IF you never get mirror reception, because 2*10,7 is 21,4, so more than 20,5...
@@xsc1000 Ah yes, makes sense, thanks!
Yes. You slipped that in the end. Is that the channel you had years and years ago? I forget what it's called
Yes ;) my other channel is danyk666
@@DiodeGoneWild did you recently open up that channel. If I recall there were alot of private videos. You should be glowing haha. You could make a wild sci-fi movie. A silent one except for all the evil noises electricity can make.
I never had any private videos...
@@DiodeGoneWild oh my bad. I have a horrible memory
@@DiodeGoneWild saying private videos is way too filthy lol
All kind of sokol radio este sold in Romania in the ussr
I HAVE A QUESTION ON RUSSIAN RADIO SCHEMATICS. On most radio schematics the ground symbols shows that the chassis is negative but on Russian schematics the symbols are showing positive or b plus chassis. Is this true?
20:44 where is the talkative Kitty ?