In this episode, we bring you an in-depth presentation on Amateur Fast Scan TV that our own Nathan, KB9GMU presented to our local amateur radio club! There is a lot of discussion of his experiences in ATV since the early 90s, as well as a demonstration of his AEA 70cm Fast Scan transceiver! We hear from @probnot's tech in Echoes From The Asylum, where he gives us his observations of the ludicrous 70s coin-op TV from a few episodes back! In Welcome To The Waves, we welcome Henry, KD9UEB to the hobby of ham radio!
Nice info in video To add ........NTSC television is a broadcast television standard utilizing an AM vestigial sideband filtered modulated carrier. NTSC transmitters are supplied a yet unmodulated input signal often referred to by users and even manufacturers as NTSC base video. . That is what was displayed on the o-scope. That signal format has 100 IRE amplitude video over -40 IRE Horizontal sync and a +/- 20 IRE 7 to 8 cycle sample of reference color burst which was is defined by the EIA RS-170-A standard and is more properly referred to as an RS170A television signal. Its Horizontal sync in the B&W days was the mentioned 15,750 Hz but with the creation of the color NTSC standard, was changed to be 15,734 Hz. The 60 HZ vertical field rate of the old B&W days was changed slightly becoming the 59.94 Hz for NTSC television. Two fields in the camera were interlaced scanned to make 1 frame of video making an RS-170A NTSC frame rate that is one half the field rate. The 59.94 Hz field rate selection was not made to avoid interference with the 6o Hz AC line frequency but to make color broadcasting compatible with the existing B&W televisions that existed at the time of the launch of NTSC (color) televisions. 60 cycle hum if permitted to enter a poorly designed RS-170A NTSC system certainly interferes readily showing as a moving vertical bar.
