UK PSA: RadioTeleSwitch Service to be withdrawn in June 2025 (30th June apparently).
If your electricity supply meter uses the RTS service to switch between peak and off peak rates then you need to ensure your electricity meter is updated as soon as possible.
Upgrading to a Smart Meter is the suggested option.
Technical details on the RTS service which send a phase modulated message via 198KHz on the BBC Radio 4 signal is covered by @officialm3hhy in this episode.
Actually not a bad design other than relying on Long Wave radio signals which uses 500KW valve based transmitters; the valves are now out of stock and no more are manufactured anywhere 🫤