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Clarified spectrum of "baseband" signal.
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Reversed Engineer
Reversed Engineer
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Note that there is a difference between a RF (radio frequency) TV signal received off the air, and the video (baseband) signal. It seems you are connecting to the antenna socket, so you are trying to see the RF signal. As @Wouter van Ooijen sais, there is zero chance of seeing that on a 'scope.

The RF signal will be at least 50MHz up to 900MHz in frequency (i.e. VHF and/or UHF). This is what the antenna will receive, at one or two microvolts at most.

After being amplified and detected by the tuner in the TV, the baseband signal will be from almost 0 up to about 6MHz, andat about 1 volt peak-to-peak. You can clearly see that on a 'scope if you look at the video output (the yellow socket) of a DVD player or VCR.

In 1987 I built a circuit to decode video from an encoded channel here in South Africa, using exactly that - an oscilliscope connected to the "video output" of a VCR tuned to the correct channel, and a PLL and some other parts :)

Please see http://en.wikipedia.org/wiki/Television_channel_frequencies regarding the RF frequencies

Please see http://en.wikipedia.org/wiki/Composite_video regarding the baseband signal

Note that there is a difference between a RF (radio frequency) TV signal received off the air, and the video (baseband) signal. It seems you are connecting to the antenna socket, so you are trying to see the RF signal. As @Wouter van Ooijen sais, there is zero chance of seeing that on a 'scope.

The RF signal will be at least 50MHz up to 900MHz in frequency (i.e. VHF and/or UHF). This is what the antenna will receive, at one or two microvolts at most.

After being amplified and detected by the tuner in the TV, the baseband signal will be up to about 6MHz, and about 1 volt peak-to-peak. You can clearly see that on a 'scope if you look at the video output (the yellow socket) of a DVD player or VCR.

In 1987 I built a circuit to decode video from an encoded channel here in South Africa, using exactly that - an oscilliscope connected to the "video output" of a VCR tuned to the correct channel, and a PLL and some other parts :)

Please see http://en.wikipedia.org/wiki/Television_channel_frequencies regarding the RF frequencies

Please see http://en.wikipedia.org/wiki/Composite_video regarding the baseband signal

Note that there is a difference between a RF (radio frequency) TV signal received off the air, and the video (baseband) signal. It seems you are connecting to the antenna socket, so you are trying to see the RF signal. As @Wouter van Ooijen sais, there is zero chance of seeing that on a 'scope.

The RF signal will be at least 50MHz up to 900MHz in frequency (i.e. VHF and/or UHF). This is what the antenna will receive, at one or two microvolts at most.

After being amplified and detected by the tuner in the TV, the baseband signal will be from almost 0 up to about 6MHz, at about 1 volt peak-to-peak. You can clearly see that on a 'scope if you look at the video output (the yellow socket) of a DVD player or VCR.

In 1987 I built a circuit to decode video from an encoded channel here in South Africa, using exactly that - an oscilliscope connected to the "video output" of a VCR tuned to the correct channel, and a PLL and some other parts :)

Please see http://en.wikipedia.org/wiki/Television_channel_frequencies regarding the RF frequencies

Please see http://en.wikipedia.org/wiki/Composite_video regarding the baseband signal

Source Link
Reversed Engineer
Reversed Engineer
  • 635
  • 5
  • 9

Note that there is a difference between a RF (radio frequency) TV signal received off the air, and the video (baseband) signal. It seems you are connecting to the antenna socket, so you are trying to see the RF signal. As @Wouter van Ooijen sais, there is zero chance of seeing that on a 'scope.

The RF signal will be at least 50MHz up to 900MHz in frequency (i.e. VHF and/or UHF). This is what the antenna will receive, at one or two microvolts at most.

After being amplified and detected by the tuner in the TV, the baseband signal will be up to about 6MHz, and about 1 volt peak-to-peak. You can clearly see that on a 'scope if you look at the video output (the yellow socket) of a DVD player or VCR.

In 1987 I built a circuit to decode video from an encoded channel here in South Africa, using exactly that - an oscilliscope connected to the "video output" of a VCR tuned to the correct channel, and a PLL and some other parts :)

Please see http://en.wikipedia.org/wiki/Television_channel_frequencies regarding the RF frequencies

Please see http://en.wikipedia.org/wiki/Composite_video regarding the baseband signal