Though rumour has it the contract will be extended again.  Because there are still loads of RTS meters out there, and not enough time to replace them.  But sooner or later the transmitters will go silent when the BBC runs out of spare valves to repair them.

The current transmitters are standard Marconi units installed in 1985 and re-tuned from 200KHz to 198kHz in 1988

Actually the Pulsam modulators were changed for something even more modern and solid state by continental in the late '90s, and the efficiency (mains power to RF conversion ) is in the 80s of %.

The valves last upwards of a decade in their current config, and they had quite a few spares when I last asked.

some history lifted from

https://www.bbceng.info/Operations/transmitter_ops/Reminiscences/Droitwich/droitwich_calling.htm

"

By late 1985 the new long-wave installation was complete and testing was taking place.  The two transmitters, type B6042 and again manufactured by the Marconi Company, were each rated at 250 kilowatts output and used a new method of modulation called the "Pulsam" system.  This was a new application of Pulse Width Modulation (P.W.M.).  So efficient was this new system that a figure of 70% overall was claimed, 10% better than even the B6034s.  The two large valves in each transmitter used a form of cooling known as vapour cooling.  Water flowing into the valve anode jacket (known as the boiler) is vaporised by the heat dissipated, fed to a cooler and condenser and  re-circulated,  the waste heat being removed by an air blast radiator. Only a few gallons of water (purified) are needed compared with the 7500 gallons required by 5XX!   Consequently a water leak, although undesirable, is not as catastrophic as in the old transmitter. The two transmitters were arranged to work in parallel with an output of 500 kilowatts using a diplexer combining circuit and automatic switching to reduce breakdown time in the event of a failure of one unit.  By the end of 1986 the new long-wave transmitters were in use for Radio 4, still providing a frequency standard using the rubidium drive, and continuing the RDS service.  On February 1st 1988, the carrier frequency of Radio 4 was changed from 200 khz to 198 khz.  This was the final  requirement of the Geneva Plan its deferment until this date was part of the plan.  The change was so small (1%) that it was unnoticeable on most receivers but it brought Radio 4 into its new allocated channel.

The last part of the re-engineering of Droitwich Transmitting Station was nearing completion at the end of the 1980s.  This was the replacement of the original Diesel Alternators by new, more efficient machines.  The four English Electric sets, admired by so many visitors in the past were scrapped and their place has been taken by two high-speed turbo-charged machines which take up half the space of the originals and provide more power!  These new engines are fully automated, running themselves up in a few seconds when required in a power failure.  In comparison the old machines, being manually controlled, took about twenty minutes to prepare for service with a consequent break in programmes of this duration if a failure of incoming power occurred."

Mike

https://www.edfenergy.com/energywise/RTS-planned-shutdown

been kicked into the long grass again , 

seems that these devices are easily fooled to switch to the cheaper traffif by the use of a software defined radio such as the rtl2832u variety on transmit and the correct software .

interesting to say the least 

There are still a lot of RTS in service in Northern Ireland, where smart meters don't appear to exist.

Until recently, there were eighteen RTS in my building alone - two of them failed in the past year or so and the DNO replaced them with electromechanical time clocks, leaving sixteen RTS still in service.

I've not seen any signs of a campaign to replace RTS still in service, either within this building, or a on a wider scale.

1. In France the national broadcaster dropped all long and mediumwave  transmissions a few years ago but the carrier complete with FSK signalling remained on air admittedly at reduced power I think it was 1100Kw instead  of 2000Kw  the signal is used for super accurate clicks and for switching of the french grid. If the electricity authorities ask permission I wonder if the same could happen here just a thought

This may also get compounded by the fact that they are starting to wind down 3G mobile signals.  I am lead to understand that some SMART meters use 2.5G but there are some out there using 3G sims cards.  Question is will the meter need to be replaced or just the sim card, either way this will use up resources. 

Question is will the meter need to be replaced or just the sim card,

Given the life of a mobile comms standard is a lot shorter than that of a traditional  electricity meter there will be some changes...

Certainly those meters that had a design freeze before the 4g stuff was standardized will have to be changed or internally modified.The saving grace, perhaps, is that most designs I have seen use a 3rd party radio board configured to act as a usb  'comm'  port connected to behave like a traditional serial modem, rather that soldering  the RF chips on board.

This is either in a box of its own, or plugs in as a daughter card to a socket on the main PCB which provides it with power and a few data lines-  The sort of folk who design the electronics for electricity meters are not up for designing what is in effect about half a mobile phone - the NRE cost is too high and cannot compete with the folk who make phones already and simply take a current design and remove the keyboard, speaker microphone and display parts.

I imagine that if the market is large enough for any given model of meter then a suitable 4g or 5g capable module will be made that is form-fit-function replacement for the previous 2G/3G one and the main meter PCB and case design can remain unaltered. There is likely to be an antenna change for different frequencies though.

And that means that some places that were in coverage on the old system will no longer be and maybe vice versa

Then in parts of the UK where things are a bit thinnner they do not use the mobile phone networks at all but a a dedicated service from telfonica

it is however a bit of a mess.
Mike

I think most of the SMETS 2 meters have a separate pluggable "communications hub" on the top of the meter (to cope with the soft southerners who have to use the mobile phone network, while the rest of the UK has a dedicated long range radio system) - so even if the mobile network has to change it should be a simple snip seals, unplug, plug and seal operation.

www.smartme.co.uk/smets-2.html

   - Andy.

It’s only eighteen months until BT Redcare closes down.

https://www.redcare.bt.com/

Will 4G or 5G signal work under my stairs?  Only time will tell.