Metropol

I'm informed, by them at Scottish Hydro, that my storage heaters are switched onto low cost power at night via a signal on radio 4.

What exactly is this signal and how does it work? I was under the impression that longwave lacked RDS style extensions so is it an actual piece of audio?

So how do you actually embed that in the signal? I mean in terms of how do you extract it?

The data is very low rate - 30 bits per minute! Some information here: http://tx.mb21.co.uk/gallery/droitwich/ ... f-data.php

What that doesn't reveal is that the BBC's RATS system, their equivalent of the IRN Obit Alarm is triggered through data in the LW transmissions.

I believe the leccy meters default to the day rate and are switched to night rate by receiving the signal. If it worked the other way round a roll of bacofoil would allow you to block the signal and leave it on cheap rate.

Steve in Pudsey wrote: I believe the leccy meters default to the day rate and are switched to night rate by receiving the signal. If it worked the other way round a roll of bacofoil would allow you to block the signal and leave it on cheap rate.

Yes, unfortunately that is the case.

I believe that the system is able to switch different meters at different times to even out the load - so that there isn't a huge power dip at midnight when millions of heaters turn on!

I'm quite lucky as when I had my meter replaced last year it was changed with a 19:00-0700 meter rather than a midnight-0700 one... from then on I get 12 hours of cheap leccy rather than the normal 7