What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70-centimeter band?
Why Cable TV systems assign channel numbers to frequencies that do not match over-the-air broadcast channels, and several mid/superband cable channels fall inside the 420-450 MHz amateur allocation. A cable-ready analog TV set can therefore tune an amateur fast-scan ATV signal directly if the transmission is placed on one of those shared cable channel frequencies (cable channels 57-61 land in the 70 cm band). No converter or downconverter is needed, just the set's cable tuning mode.
Watch out Converted satellite dishes are for microwave reception and do nothing to make a TV tune 70 cm; the USB-and-sound-card method describes slow-scan TV (SSTV) on HF, not fast-scan ATV.
70 cm ATV = cable channels. A cable-ready TV already tunes 420-450 MHz.