All change to DAB radio

[ronsurf]

: http://www.theguardian.com/media/2011/oct/09/bbc-radio4-long-wave-goodbye

Someone must have had a quiet word with the Guardian. They wrote this 12 days later:

http://www.theguardian.com/media/2011/oct/21/radio-4-controller-reassures-future

 

[JumbleDuck]

Someone must have had a quiet word with the Guardian. They wrote this 12 days later:

http://www.theguardian.com/media/2011/oct/21/radio-4-controller-reassures-future

I don't think there is any contradiction or retraction there. The first article says

BBC Radio 4 long wave, which transmits on the 198 kilohertz frequency, relies on ageing transmitter equipment that uses a pair of the valves – no longer manufactured – to function.

The valves, at Droitwich in Worcestershire, are so rare that engineers say there are fewer than 10 in the world, and the BBC has been forced to buy up the entire global supply. Each lasts anywhere between one and 10 years, and when one of the last two blows the service will go quiet.​

while second says

Reports of the death of BBC Radio 4's long wave broadcasts may be a little premature, it seems. They could continue for at least another 10 years, according to Radio 4 controller Gwyneth Williams.​

Of course "they could continue for at least another 10 years" is about as vague as Debenham's "up to 50% or more off selected items", but ten years, ish, sounds like a reasonable service life estimate for a system with fewer than ten spare parts which are needed every 1 to 10 years available.

 

[2Tizwoz]

Once that happens we won't have a radio at home as DAB doesn't work in our house! Same as analogue TV. We can't get Freeview so had to buy satellite. B*stard government cons

We have had to change to satellite for the same reason.

 

[lw395]

I don't think there is any contradiction or retraction there. The first article says

BBC Radio 4 long wave, which transmits on the 198 kilohertz frequency, relies on ageing transmitter equipment that uses a pair of the valves – no longer manufactured – to function.

The valves, at Droitwich in Worcestershire, are so rare that engineers say there are fewer than 10 in the world, and the BBC has been forced to buy up the entire global supply. Each lasts anywhere between one and 10 years, and when one of the last two blows the service will go quiet.​

while second says

Reports of the death of BBC Radio 4's long wave broadcasts may be a little premature, it seems. They could continue for at least another 10 years, according to Radio 4 controller Gwyneth Williams.​

Of course "they could continue for at least another 10 years" is about as vague as Debenham's "up to 50% or more off selected items", but ten years, ish, sounds like a reasonable service life estimate for a system with fewer than ten spare parts which are needed every 1 to 10 years available.

And when the last valves are gone, it would be possible to build a new 198kHz transmitter, with no valves in it.
These days you'd use transistors, but it would be a whole new transmitter, not plugging in a replacement like changing a board in your PC.
It would of course be silly to leave it to the last minute.
And the question might be asked, do we need it?

 

[Buck Turgidson]

Solid state drop in replacement valves are widely available.

 

[JumbleDuck]

And when the last valves are gone, it would be possible to build a new 198kHz transmitter, with no valves in it.
These days you'd use transistors, but it would be a whole new transmitter, not plugging in a replacement like changing a board in your PC.

Of course. However, it wouldn't be an off-the shelf or cheap purchase: 500kW is a fair old RF power. And, as you say, do we need it?[/QUOTE]

 

[JumbleDuck]

Solid state drop in replacement valves are widely available.

Rated at 500kW? Someone should tell the BBC.

 

[st599]

Solid state drop in replacement valves are widely available.

At 500 kW average load?

 

[jerrytug]

What happens to the old valves, one would make a great chandelier or something!

 

[ronsurf]

Solid state drop in replacement valves are widely available.

I'd be interested in seeing how these compare to the 6L6s in my guitar amp. Do they really handle 600V and 50W?

 

[doug748]

And when the last valves are gone, it would be possible to build a new 198kHz transmitter, with no valves in it.
These days you'd use transistors, but it would be a whole new transmitter, not plugging in a replacement like changing a board in your PC.
It would of course be silly to leave it to the last minute.
And the question might be asked, do we need it?

Exactly, someone has decided they want rid of it and they come up with a volley of feeble excuses; always a giveaway that one. Sticking up a new mast would cost "many millions" or about a quarter of a new series of Top Gear.

There will be the usual politics and internal wrangles and then we will hear "Oh dear the knobs fell off" in about 10 years time

 

[elton]

Exactly, someone has decided they want rid of it and they come up with a volley of feeble excuses; always a giveaway that one. Sticking up a new mast would cost "many millions" or about a quarter of a new series of Top Gear.

There will be the usual politics and internal wrangles and then we will hear "Oh dear the knobs fell off" in about 10 years time

I agree. The government, backed by the BBC, are determined to foist the entirely useless DAB on us, regardless of the facts or the consequences.

 

[JumbleDuck]

Exactly, someone has decided they want rid of it and they come up with a volley of feeble excuses; always a giveaway that one. Sticking up a new mast would cost "many millions" or about a quarter of a new series of Top Gear.

How much does a 1/2 megawatt LW transmitter cost these days?

 

[lw395]

How much does a 1/2 megawatt LW transmitter cost these days?

And half a megawatt, divided by the number of people listenng to it is probably not very efficient.

 

[ronsurf]

The BBC aren't the only people broadcasting on LW though, are they? There are other stations on there, so how are they doing it? Are they all dependent on the remaining stock of valves that the BBC have bought?

 

[JumbleDuck]

The BBC aren't the only people broadcasting on LW though, are they? There are other stations on there, so how are they doing it? Are they all dependent on the remaining stock of valves that the BBC have bought?

There's very little on LW these days. If Wikipedia is to be believed just 26 broadcast stations worldwide (http://en.wikipedia.org/wiki/Longwave#List_of_longwave_broadcasting_transmitters) and in many case coverage comes from several small transmitters rather that one stonking huge one like Droitwich (yes, BBC4 has a couple of smaller ones oop north).

Of course the BBC could be lying about the valves. Discussion of that is probably best taken to the Lounge, where it will undoubtedly be blamed on gay Romanians.

 

[JumbleDuck]

The BBC aren't the only people broadcasting on LW though, are they? There are other stations on there, so how are they doing it? Are they all dependent on the remaining stock of valves that the BBC have bought?

There's very little on LW these days. If Wikipedia is to be believed just 26 broadcast stations worldwide (http://en.wikipedia.org/wiki/Longwave#List_of_longwave_broadcasting_transmitters) and in many case coverage comes from several small transmitters rather that one stonking huge one like Droitwich (yes, BBC4 has a couple of smaller ones oop north).

RTÉ have a 500kW LW transmitter - the old Atlantic 252 one - which is due to be decommissioned in two years. By a curious coincidence it will be broadcasting my dulcet tones tomorrow ...