[retrotecchie]

...and i fully expect Government will find a way to to keep RTS running for another year to 2026

The Droitwich transmitter will be in operation for at least another two years. The RTS system is used for many other purposes than just energy metering...

The Environment Agency use RTS, as do a couple of other entities. Every 'legacy' communications system that was supposed to have been deprecated is still mothballed and ready to be cranked up again as required. Even the Loran-C station at Anthorn is still banging out a signal, almost a decade after Loran-C was allegedly switched off.

So they won't be broadcasting R4 Long Wave after June '25 but the RTS will still be running for a long time yet. They will reduce the TX power as AM needs a lot of 'oomph' but the PSK signal only needs a few percent of the power of an audio transmission. I can receive and decode both German and Hungarian RTS signals almost 900 miles away from their transmitters.

Which is exactly why many new RTS services are being rolled out around the world...because it works.

[meldrewreborn]

@retrotecchie so are customers being lied to, so to increase the uptake of smart meters (surely not😄😇) or for any other reason best known to authority?

[retrotecchie]

@meldrewreborn

The real reason is money, no doubt. All RTS users which include not only the suppliers but the DNOs, plus other agencies have to pay to use the service. That has to come out of their operating costs. Smart metering is paid for by the punter out of their Standing Charges.

[meldrewreborn]

While the transmitter will still be functional, presumably its signal are at various frequencies and codings, so the RTS signal must be unique so that customers are not impacted by other transmissions. And we know that the off peak times are not consistent across the UK.

so is it a case of RTS sending out lots of signals and the discrimination is contained within the customer’s equipment?

[retrotecchie]

@meldrewreborn

The 198kHz carrier frequency is amplitude modulated by audio to generate the Radio 4 broadcast. However, the carrier has a digital code superimposed on it by modulating the phase of the carrier. Phase Shift Keying. Inaudible to the normal AM reception, but easily allows the digital data to be recovered by RTS equipment.

All users of the system have their own unique codes which are used in each digital message. Meters, time switches, pumping stations, sluicegates, flood warning sirens (and air raid sirens up until 1995) and anything else that uses RTS will only respond to their designated codes.

Here's the blurb from UK Energy Networks :

The system basically comprises user terminals and modems, the central teleswitch control unit (CTCU) the LF Data System, the 198kHz BBC Radio Four transmission system and radio teleswitching receiver controllers (RCs).
Each user of the system, the electricity distribution networks operators and electricity transmission network operator has a unique set of codes enabling them to address only their own block of meters and switches.
These instructions are sent by the network operators to the Central Teleswitch Control Unit (CTCU) housed and maintained by Cygnet Solutions.
The CTCU processes and forwards their switching codes to the BBC Message Assembler at Crystal Palace.
Here, the electricity industry codes are combined with the instructions from other users of the service and sent to the three national networks of transmitters. The main transmitter at Droitwich (see also the BBC site), rated at 500kW, can reach most parts of the UK and some parts of continental Europe while the two smaller transmitters located at Westerglen and Burghead cover Scotland and Northern Ireland.
Messages are encoded onto the Amplitude Modulated (AM) Radio 4 signal using Phase Shift Keying (PSK) techniques.
30 messages are transmitted per minute, each message having 50 bits of data. 18 of these bits are taken up by a BBC header and Cyclic Redundancy Check (CRC) tail. 32 bits are available for data.
The RadioTeleswitch specification (BS7647) lays down specific formats for its user message contents. Two message types are defined:

• command (or immediate) which has priority of broadcast, and on receipt immediately sets a Teleswitch (RCs) internal switches to required status, overriding any programmed status;
• programme, which updates or refreshes the operating program stored within a Teleswitch (i.e. internal switches will not change status until required by the program).

An ‘immediate’ instruction can take one or two minutes from initiation of a request at the terminal of a user, depending on other traffic on the data system, and is intended to allow fast, broadcast load shedding.
The system’s ability to offer users both programmed and immediate broadcast control have enabled companies using the system to provide weather-related control of electricity storage heaters in specialised arrangements such as ‘budget warmth’ and ‘heat with rent’ schemes.


The transmission of cost reflective messages and weather forecast information has allowed the concept of controlled consumption to be extended to provide more comprehensive forms of premium heating and other services. The ability to influence demand patterns more finely so that they respond more immediately to changes in supply cost, is to the advantage of both suppliers and customers. It gives customers another form of choice.

Anyway, for those in the know (and subject to the OSA), abandoning RTS will have consequences and repercussions which go far beyond the energy sector. It rather worries me, to be honest.