Warning meters in 300,000 homes could stop working

My understanding, is that BBC long wave radio transmissions including the radio teleswitch signals are due to be ceased in the near future.

The long wave transmitters use very large glass valves and supplies of replacements are claimed to be limited. Such large and specialised valves were never a stock item. It cant be that hard to make them to order, as used to be done.

Coded messages inserted into BBC long wave radio signals are also reputedly used to pass instructions to our nuclear submarines, a matter of some importance.

Back when I worked at the BBC, over 40 years ago, we had a visit to the Droitwich transmitter. Even then, one look at it and it was astounding that they were able to keep it going. As you say, VERY large valves. It was already on borrowed time then. Wonderful place to visit though! It would make a wonderful museum (in a very similar vein to how Kew Bridge pumping station is) but sadly probably mainly appealing to engineering nerds like me...

Keeping things like that going are more a question of need/demand and perhaps political will power. The sort of folk that make elements for particle accelerators and electron microscopes (and we have both in Britain) would be perfectly capable of making (or re-cathoding ) transmitter valves- the diagrams are available, - if anything it's not even that fiddly compared to making, say, a laser tube. The real problem is that nostalgia does not pay, and longwave, and medium wave to an extent, are quite expensive to run, and worse, at least in the UK, are not protected from the rise of interference from switching power supplies, ADSL and so on, and are almost unusable in some built up areas.

Mike.

Keeping things like that going are more a question of need/demand and perhaps political will power. The sort of folk that make elements for particle accelerators and electron microscopes (and we have both in Britain) would be perfectly capable of making (or re-cathoding ) transmitter valves- the diagrams are available, - if anything it's not even that fiddly compared to making, say, a laser tube. The real problem is that nostalgia does not pay, and longwave, and medium wave to an extent, are quite expensive to run, and worse, at least in the UK, are not protected from the rise of interference from switching power supplies, ADSL and so on, and are almost unusable in some built up areas.

Mike.