Andrew Dorey writes about a way to capture video from old computers that only have RF output. Machines like the ZX81 modulated their video onto a UHF carrier because televisions were the display of choice in the 1970s and 80s. UK analogue broadcasts ended in 2012, so a modern TV will not tune them, and filming a CRT gives you a rolling black bar.

His answer was a Philips AV7300, bought on eBay. First sold in 1987, it is an analog TV without the screen: aerial in, composite video and audio out on phono connectors. It stores twelve presets, each tuned by hand with its own dial and LED. Inside is a single sided board with through hole parts and no digital electronics, built around the IF section of the Philips System 4 (K40) chassis.

After replacing perished rubber feet and checking the capacitors, he found it only outputs video once it locks onto an RF signal.…