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Use graphics card to transmit RF output.

babadoctor
By babadoctor
in Graphics Cards
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Go to solution Solved by mariushm,

Modern video cards don't have VGA anymore.

 

DAC is  short for Digital to Analogue Converter , it's a section of the video card chip which takes the digital signal (a series of bits 1s and 0s for every  pixel in every frame that's sent to the monitor) and converts those bits in three voltages, one for each red , green and blue part of the RGB pixel, and it repeats that for every pixel in every frame sent through the vga connector.

 

The voltage could be between 0v and 0.75v, for example if the red part of your pixel is at half intensity (127, because you have 8 bits per color, so 0.. 255 values per color), then the DAC produces let's say 0.38v and puts it on the vga pin that sends the RED color to the monitor and keeps that voltage for a few nanoseconds ( 1000 ms divided by number of frames let's say 85  and then divided by number of pixels let's say 1024x768 = ~786432 ... so for 1000 / 85 / 786 432 = 0.00001495 ms

 

Anyway the idea is that a few million times a second, the voltage on three pins on your vga connector may change depending on what's on screen, depending on color of pixels.

 

Like  I said modern video cards (RX series from AMD and Pascal aka GT and GTX 10xx from nVidia) no longer have this analogue circuitry on them). You'll need older cards to attempt to use the video card like in that guide.

Also note that the more modern the card is the more likely the card will have additional circuitry to smooth out and filter and make the signal output on vga cleaner, so the software may not work as well as that guy managed to achieve.

Posted

Does anyone here know how can I use a graphics card to transmit an RF signal? 

 

 

 

OFF TOPIC: I suggest every poll from now on to have "**CK EA" option instead of "Other"

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Search for  "RF MODULATOR" , for example : https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Delectronics&field-keywords=rf+modulator

 

They're tiny things that convert S-video or Composite to RF out compatible with NTSC or PAL (for Europe)

 

Modern video cards don't output vga or svideo/composite anymore, so you may need  HDMI to TV converters (which have a chip inside that converts the digital signal into analogue and convert it to svideo or composite) for example here's 3 random search results from amazon :

https://www.amazon.com/S-video-Converter-Composite-Multimedia-Interface1080P/dp/B01N5S9ET8/ref=sr_1_5?s=electronics&ie=UTF8&qid=1523908949&sr=1-5&keywords=hdmi+to+svideo+composite

 

https://www.amazon.com/Goodes-S-Video-Composite-Converter-Blue-Ray/dp/B01EMTYP46/ref=sr_1_6?s=electronics&ie=UTF8&qid=1523908949&sr=1-6&keywords=hdmi+to+svideo+composite

https://www.amazon.com/Wiistar-Converter-Definition-Multimedia-Interface1080P/dp/B012MDMWLM/ref=sr_1_7?s=electronics&ie=UTF8&qid=1523908949&sr=1-7&keywords=hdmi+to+svideo+composite

 

so hdmi - > hdmi to svideo/composite converter -> svideo/composite to RF modulator -> RF in (tv)

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3 minutes ago, mariushm said:

Search for  "RF MODULATOR" , for example : https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Delectronics&field-keywords=rf+modulator

 

They're tiny things that convert S-video or Composite to RF out compatible with NTSC or PAL (for Europe)

 

Modern video cards don't output vga or svideo/composite anymore, so you may need  HDMI to TV converters (which have a chip inside that converts the digital signal into analogue and convert it to svideo or composite) for example here's 3 random search results from amazon :

https://www.amazon.com/S-video-Converter-Composite-Multimedia-Interface1080P/dp/B01N5S9ET8/ref=sr_1_5?s=electronics&ie=UTF8&qid=1523908949&sr=1-5&keywords=hdmi+to+svideo+composite

 

https://www.amazon.com/Goodes-S-Video-Composite-Converter-Blue-Ray/dp/B01EMTYP46/ref=sr_1_6?s=electronics&ie=UTF8&qid=1523908949&sr=1-6&keywords=hdmi+to+svideo+composite

https://www.amazon.com/Wiistar-Converter-Definition-Multimedia-Interface1080P/dp/B012MDMWLM/ref=sr_1_7?s=electronics&ie=UTF8&qid=1523908949&sr=1-7&keywords=hdmi+to+svideo+composite

 

so hdmi - > hdmi to svideo/composite converter -> svideo/composite to RF modulator -> RF in (tv)

 

Well let me add to my question because I wasn't clear...

 

I wanted to transmit an RF frequency ONLY using a graphics card.

 

I did some research and I found this: https://bk.gnarf.org/creativity/vgasig/ 

 

which is what I want, but I am not sure what a "VGA DAC" is.

 

I know what VGA is: image.png.f847033024ddda40f5ded0210838fc0a.png

But not VGA DAC

OFF TOPIC: I suggest every poll from now on to have "**CK EA" option instead of "Other"

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Modern video cards don't have VGA anymore.

 

DAC is  short for Digital to Analogue Converter , it's a section of the video card chip which takes the digital signal (a series of bits 1s and 0s for every  pixel in every frame that's sent to the monitor) and converts those bits in three voltages, one for each red , green and blue part of the RGB pixel, and it repeats that for every pixel in every frame sent through the vga connector.

 

The voltage could be between 0v and 0.75v, for example if the red part of your pixel is at half intensity (127, because you have 8 bits per color, so 0.. 255 values per color), then the DAC produces let's say 0.38v and puts it on the vga pin that sends the RED color to the monitor and keeps that voltage for a few nanoseconds ( 1000 ms divided by number of frames let's say 85  and then divided by number of pixels let's say 1024x768 = ~786432 ... so for 1000 / 85 / 786 432 = 0.00001495 ms

 

Anyway the idea is that a few million times a second, the voltage on three pins on your vga connector may change depending on what's on screen, depending on color of pixels.

 

Like  I said modern video cards (RX series from AMD and Pascal aka GT and GTX 10xx from nVidia) no longer have this analogue circuitry on them). You'll need older cards to attempt to use the video card like in that guide.

Also note that the more modern the card is the more likely the card will have additional circuitry to smooth out and filter and make the signal output on vga cleaner, so the software may not work as well as that guy managed to achieve.

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57 minutes ago, mariushm said:

Modern video cards don't have VGA anymore.

 

DAC is  short for Digital to Analogue Converter , it's a section of the video card chip which takes the digital signal (a series of bits 1s and 0s for every  pixel in every frame that's sent to the monitor) and converts those bits in three voltages, one for each red , green and blue part of the RGB pixel, and it repeats that for every pixel in every frame sent through the vga connector.

 

The voltage could be between 0v and 0.75v, for example if the red part of your pixel is at half intensity (127, because you have 8 bits per color, so 0.. 255 values per color), then the DAC produces let's say 0.38v and puts it on the vga pin that sends the RED color to the monitor and keeps that voltage for a few nanoseconds ( 1000 ms divided by number of frames let's say 85  and then divided by number of pixels let's say 1024x768 = ~786432 ... so for 1000 / 85 / 786 432 = 0.00001495 ms

 

Anyway the idea is that a few million times a second, the voltage on three pins on your vga connector may change depending on what's on screen, depending on color of pixels.

 

Like  I said modern video cards (RX series from AMD and Pascal aka GT and GTX 10xx from nVidia) no longer have this analogue circuitry on them). You'll need older cards to attempt to use the video card like in that guide.

Also note that the more modern the card is the more likely the card will have additional circuitry to smooth out and filter and make the signal output on vga cleaner, so the software may not work as well as that guy managed to achieve.

Hmmm.. so would this work with any old GPU with a dsub connector on it?

OFF TOPIC: I suggest every poll from now on to have "**CK EA" option instead of "Other"

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Probably.

Note that VGA cables are usually insulated, the wires inside are shielded, so if you want the vga cable to act like an antenna (fm transmitter), you probably want to source one vga connector and solder loose wires to the actual wires (  see http://pinouts.ru/Video/VGA15_pinout.shtml - 1, 2,3, 5,6,7,8, 10, 13,14 are probably the minimum amount of connections you need to have a functioning vga cable)

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1 hour ago, mariushm said:

Probably.

Note that VGA cables are usually insulated, the wires inside are shielded, so if you want the vga cable to act like an antenna (fm transmitter), you probably want to source one vga connector and solder loose wires to the actual wires (  see http://pinouts.ru/Video/VGA15_pinout.shtml - 1, 2,3, 5,6,7,8, 10, 13,14 are probably the minimum amount of connections you need to have a functioning vga cable)

Okay!

 

I will attempt this with an r9 270x.

 

(correction: i will attempt with integrated graphics on my i5 4440)

OFF TOPIC: I suggest every poll from now on to have "**CK EA" option instead of "Other"

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