**Converting a CRT TV into an Oscilloscope: A DIY Project**

I was determined to turn my old CRT TV into a working oscilloscope, and I'm excited to share my journey with you. The goal was simple: to display a voltage signal on the screen using the TV's vertical deflection coil.

The first step involved understanding how the TV's internal components worked. I initially assumed that the 50 Hertz ramp function would deflect the electron beam horizontally, so I followed the wires from the terminals and tried to remove the connector. However, after cutting through the red and blue wires of the 15 kilo Hertz coil, I was surprised to see only a vertical line on the screen. This meant that my assumption was wrong, and it was actually the other way around.

Since I had already messed things up, I decided to use my function generator to set a 50 Hertz sine wave with a peak-to-peak voltage of Harper volts. I connected this signal to the horizontal deflection coil, but the result was disappointing – there was only an unimpressive deflection of the electrons. The reason for this was that the voltage of the function generator collapsed after connecting it to the coil, which had an impedance of 0.6 ohm and inductance of 0.2 one milli Henry.

To fix this issue, I utilized a Class B audio amp powered with the 12 volt power source. I connected a sine wave to the left input channel of the amp and its output to the coil. This setup allowed me to see the amplified signal on the screen, but it was a bit too high, so I decreased the output level of the function generator to ensure that the amplified signal had a peak-to-peak voltage of 6 volts.

With this adjustment, I could utilize the full horizontal range of the TV and have some fun with different signals. However, since this would still be an upside-down oscilloscope, I reconnected the red and blue wires and separated the gray and yellow warning stats to achieve the desired horizontal line. Hooking up the amplified sine wave through the vertical deflection coil allowed me to see the signal on the screen, but it was not easily recognizable.

This was because the resistance and inductance of this coil were bigger than the previous one, so I needed to increase the peak-to-peak voltage up to 13 volts to utilize the complete vertical range of the TV. However, even with this adjustment, the signal was still not clearly visible on the screen. The reason for this was that the horizontal deflection had a frequency of 15.6 kilo Hertz, which decreased the Y range due to the increasing impedance of the coil.

To achieve any kind of acceptable results, I separated the red and blue wires once again, creating only a light spot on the TV screen. Using an Arduino Nano in combination with a PCF eight five nine one 8-bit DAC and some codes, I created a ramp function with a frequency of roughly 50 Hertz. This signal was connected to a potentiometer as a voltage divider, which then passed it to the right input channel of the amp.

This setup allowed me to create an adjustable AC ramp function at the right output channel. The amplified signal was then connected to the horizontal deflection coil and could be fine-adjusted with the potentiometer to stretch the electron beam across the whole X area of the screen.

At this point, I could finally reconnect the sine wave of the function generator to the left channel of the amp and its output to the vertical deflection coil. As you can see in the video, this setup allowed me to examine the voltage signal of my function generator and possibly some other simple waveforms.

As a finishing touch for my oscilloscope, I connected the sine wave to an analog input of the Arduino and used the analog read function to trigger the ramp waveform at a certain point of the sine wave. This meant that by fine-tuning the offset of the signal, I could lock it in place and investigate it even better.

Needless to say, this is still just a crude attempt to convert a CRT TV into an oscilloscope, but I hope you liked this video! If so, don't forget to Like, share, and subscribe – that would be awesome. Stay creative, and I will see you next time!

WEBVTTKind: captionsLanguage: enrecently I found this old portable CRT TV here in my basements by simply plugging in a DC connector applying 12 volt DC and turning the power flash volume adjustment wheel the TV is slowly turns on and draws around 1.2 m/s now I could either utilize a built-in antenna and the frequency adjustment wheel to search for broadcasting channels that like I expected don't exist anymore nowadays all I could switch to the monitor modes connect a composite video signal from a classical video game console and enjoy one of the best platformer games but since the picture of my TV is already distorted and honestly not a pleasure to look at let's delay the gaining fun for now and instead I will show you in this episode effects how we can utilize the properties of such a CRT TV in order to create a very crude of Scylla scope that is not only interesting to look at but also in one way or another partly functional let's get started after removing full visible screws it was pretty easy to looked up the bigger parts of the housing on the inside we can see it not only a ton of interesting windage electronics but also the main side back transformer which connects to the back and the front of the cathode ray tube whose abbreviation is CRT as in CRT TV the 5x transformer provides a high voltage to accelerate the electrons generated by the electron gun to form an electron beam which hits the phosphorescent screen and thus creates light spots but since we don't want the static points because an oscilloscope is usually used to examine constantly changing signals we need to utilize the two deflection coils of the system if we look at it from the front we see one continuous coil on the top and bottom and another one left and right from the tube by applying a voltage to such a coil current will flow which creates magnetic fields that will deflect the electron beam so in conclusion the top and bottom coil is the vertical deflection coil that will move the electron beam in the Y direction and the left and right coil is the horizontal deflection coil which will move the electrons in the X direction but which coil is which you might ask well to find that out I firstly connected to my differential probes to the blue and red wire coil after turning on the DB year we can see black pictures since there's no input video signal and the oscilloscope presents us in AC square wave with people's ages of 30 to 40 volts and a frequency of around fifteen point six kilos since that is clearly not the 50 Hertz refresh rate of the TV I connected my probes to the yellow and gray wire coil instead turn on the TV and saw the anticipated close enough to 50 Hertz AC ramp function with people that just up around seven bowls as stupid as I am I initially thought that this 50 Hertz ramp function deflects the electron beam horizontally so I followed the car wires from the terminals try to remove the connector gave up and simply cut through the red and blue virus of the 15 kilo Hertz coil but surprised after turning on the TV we can only see a vertical line meaning that my assumption was wrong it is actually at the other way round but since I already screwed up this porridge I simply got my function generator set it to a 50 Hertz sine wave with a peak to peak voltage of Harper volts and connected it to the horizontal deflection coil which caused a rather unimpressive deflection of the electrons the reason for this is that the voltage of the function generator collapsed after connecting it to the coil since the function generator has an impedance of 50 ohm and the coil Wilbert resistance of 0.6 ohm and in inductance of 0.2 one milli Henry and impedance up around 0.6 own that means most of the voltage will drop across the 50 ohm instead of the 0.6 ohm of the coil to fix that I simply utilize the Class B audio amp which are also powered with the 12 volt power source after connecting a sine wave to the left input channel of the M and its output to the coil we can see that the amplification factor was a bit too high so we're decreasing the output level of the function generator so that the amplified signal has a peak to peak voltage of 6 volts we can utilize the full horizontal range of the TV and we can have a bit of fun with different signals but since this would still be an upside-down oscilloscope I reconnected the red and blue wire and separated the gray and yellow warning stats which finally led to the desired horizontal line by hooking up the amplified sine wave through the vertical deflection coil we can kind of see the signal on the screen but because the resistance and inductance of this coil is bigger than the previous one we need to increase the peak-to-peak voltage up to 13 volts in order to utilize the complete vertical range of the TB now the signal is still not easily recognizable because the horizontal deflection still has a frequency of 15.6 kilo hertz and increasing the frequency of our sine wave is also not the best idea because the Y range decreases due to the increasing impedance of the coil so in order to achieve any kind of acceptable results I separated the red and blue wire once again which should now only create a light spot on the TV screen and use an Arduino Nano in combination with a PCF eight five nine one 8-bit DAC and a bit of codes to create a ramp function with a frequency of roughly of 50 Hertz I connected the signal to a potentiometer as a voltage divider which then passes it to the right input channel of the amp to create an adjustable AC ramp function at the right output channel this amplified signal then connects to the horizontal deflection coil and can be fine adjusted with the potentiometer to stretch the electron beam across the whole X area of the screen at this point we can finally reconnect the sine wave of the function generator to the left channel of the amp and the output of it to the vertical deflection coil as you can see with this setup we can definitely examine the voltage signal of my function generator and possibly some other simple waveforms so as a finishing touch for my kudos or scope I connected the sine wave to an analog input of the Arduino and use the analog read function to trigger the ramp waveform at a certain point of the sine wave that means that by fine tuning the offset of the signal we can lock it in place and investigate it even better but needless to say this is still just a crude attempt to convert a CRT TV into an oscilloscope go there is still plenty of features missing from a proposal of scope and put that being said I hope you liked this video if so don't forget to Like share and subscribe that would be awesome stay creative and I will see you next timerecently I found this old portable CRT TV here in my basements by simply plugging in a DC connector applying 12 volt DC and turning the power flash volume adjustment wheel the TV is slowly turns on and draws around 1.2 m/s now I could either utilize a built-in antenna and the frequency adjustment wheel to search for broadcasting channels that like I expected don't exist anymore nowadays all I could switch to the monitor modes connect a composite video signal from a classical video game console and enjoy one of the best platformer games but since the picture of my TV is already distorted and honestly not a pleasure to look at let's delay the gaining fun for now and instead I will show you in this episode effects how we can utilize the properties of such a CRT TV in order to create a very crude of Scylla scope that is not only interesting to look at but also in one way or another partly functional let's get started after removing full visible screws it was pretty easy to looked up the bigger parts of the housing on the inside we can see it not only a ton of interesting windage electronics but also the main side back transformer which connects to the back and the front of the cathode ray tube whose abbreviation is CRT as in CRT TV the 5x transformer provides a high voltage to accelerate the electrons generated by the electron gun to form an electron beam which hits the phosphorescent screen and thus creates light spots but since we don't want the static points because an oscilloscope is usually used to examine constantly changing signals we need to utilize the two deflection coils of the system if we look at it from the front we see one continuous coil on the top and bottom and another one left and right from the tube by applying a voltage to such a coil current will flow which creates magnetic fields that will deflect the electron beam so in conclusion the top and bottom coil is the vertical deflection coil that will move the electron beam in the Y direction and the left and right coil is the horizontal deflection coil which will move the electrons in the X direction but which coil is which you might ask well to find that out I firstly connected to my differential probes to the blue and red wire coil after turning on the DB year we can see black pictures since there's no input video signal and the oscilloscope presents us in AC square wave with people's ages of 30 to 40 volts and a frequency of around fifteen point six kilos since that is clearly not the 50 Hertz refresh rate of the TV I connected my probes to the yellow and gray wire coil instead turn on the TV and saw the anticipated close enough to 50 Hertz AC ramp function with people that just up around seven bowls as stupid as I am I initially thought that this 50 Hertz ramp function deflects the electron beam horizontally so I followed the car wires from the terminals try to remove the connector gave up and simply cut through the red and blue virus of the 15 kilo Hertz coil but surprised after turning on the TV we can only see a vertical line meaning that my assumption was wrong it is actually at the other way round but since I already screwed up this porridge I simply got my function generator set it to a 50 Hertz sine wave with a peak to peak voltage of Harper volts and connected it to the horizontal deflection coil which caused a rather unimpressive deflection of the electrons the reason for this is that the voltage of the function generator collapsed after connecting it to the coil since the function generator has an impedance of 50 ohm and the coil Wilbert resistance of 0.6 ohm and in inductance of 0.2 one milli Henry and impedance up around 0.6 own that means most of the voltage will drop across the 50 ohm instead of the 0.6 ohm of the coil to fix that I simply utilize the Class B audio amp which are also powered with the 12 volt power source after connecting a sine wave to the left input channel of the M and its output to the coil we can see that the amplification factor was a bit too high so we're decreasing the output level of the function generator so that the amplified signal has a peak to peak voltage of 6 volts we can utilize the full horizontal range of the TV and we can have a bit of fun with different signals but since this would still be an upside-down oscilloscope I reconnected the red and blue wire and separated the gray and yellow warning stats which finally led to the desired horizontal line by hooking up the amplified sine wave through the vertical deflection coil we can kind of see the signal on the screen but because the resistance and inductance of this coil is bigger than the previous one we need to increase the peak-to-peak voltage up to 13 volts in order to utilize the complete vertical range of the TB now the signal is still not easily recognizable because the horizontal deflection still has a frequency of 15.6 kilo hertz and increasing the frequency of our sine wave is also not the best idea because the Y range decreases due to the increasing impedance of the coil so in order to achieve any kind of acceptable results I separated the red and blue wire once again which should now only create a light spot on the TV screen and use an Arduino Nano in combination with a PCF eight five nine one 8-bit DAC and a bit of codes to create a ramp function with a frequency of roughly of 50 Hertz I connected the signal to a potentiometer as a voltage divider which then passes it to the right input channel of the amp to create an adjustable AC ramp function at the right output channel this amplified signal then connects to the horizontal deflection coil and can be fine adjusted with the potentiometer to stretch the electron beam across the whole X area of the screen at this point we can finally reconnect the sine wave of the function generator to the left channel of the amp and the output of it to the vertical deflection coil as you can see with this setup we can definitely examine the voltage signal of my function generator and possibly some other simple waveforms so as a finishing touch for my kudos or scope I connected the sine wave to an analog input of the Arduino and use the analog read function to trigger the ramp waveform at a certain point of the sine wave that means that by fine tuning the offset of the signal we can lock it in place and investigate it even better but needless to say this is still just a crude attempt to convert a CRT TV into an oscilloscope go there is still plenty of features missing from a proposal of scope and put that being said I hope you liked this video if so don't forget to Like share and subscribe that would be awesome stay creative and I will see you next time