Commemorating the death of analog TV

[tubesrule]

Originally Posted by Jeffhs

Unless there is some difference in circuitry between RF modulators used with high-definition video systems and those designed for use with standard 525-line NTSC analog televisions, VCRs, etc., I do not think it should matter (IMHO) whether the output signal from the STB sent to an RF modulator is 720/1080 digital (ATSC) or 525-line NTSC analog. I'd think the modulator wouldn't care (figuratively speaking) what type of signal it was converting, as long as it is video and audio; it will be downconverted to VHF channel 3 or 4, regardless.

This is the problem. As Charles already pointed out, if the STB only has a 720/1080 output, it's useless to send to a modulator. While the modulator won't care what signal is sent to it, your TV requires a NTSC signal and will not work with a 720/1080 signal. You would first need to down convert the STB output from 720/1080 to 525 (actually 480i) and then send to a modulator.