24-04-2022, 12:16 PM
With digitising you need a lot more bits resolution for more bandwidth than one station. The resolution needed increases as the bandwidth increases.
Also the ADCs all have less real dynamic range than the number of bits resolution suggests.
Jeffery is quite right about the VCR issues, except the dynamic range is nothing like good enough even if you solved the sync issues. Perhaps you could record frame sync on audio track on edge (or maybe in the FM subcarrier on a VHS with a nicam tuner) and line sync (if needed) on Colour Under channel on a modified VHS.
The cheap SDRs based on an upconverter to more than 42MHz and a USB TV stick are nearly useless because they have only 8 bit ADC in the mode where MPEG stream decoder is bypassed.
Also the ADCs all have less real dynamic range than the number of bits resolution suggests.
Jeffery is quite right about the VCR issues, except the dynamic range is nothing like good enough even if you solved the sync issues. Perhaps you could record frame sync on audio track on edge (or maybe in the FM subcarrier on a VHS with a nicam tuner) and line sync (if needed) on Colour Under channel on a modified VHS.
The cheap SDRs based on an upconverter to more than 42MHz and a USB TV stick are nearly useless because they have only 8 bit ADC in the mode where MPEG stream decoder is bypassed.
