To add to what Keith has said.
Re Sidmouth you are quite right.
It was crewed by a Birmingham team of OB engineers and Studio Managers (The prog was produced in Brum at the time), and they normally used SCV6 (a very large truck with an SSL desk in it, watching it park behind the cinema was always a laugh!).
Some years the programme was even broadcast live from the cinema, with some pre-recorded items between the live acts.
As the whole operation was "In-House" so to speak, all the gear needed came free, the only expenses being salaries for staff etc.
Then along came John Birt and "Producer Choice", trying to turn the Beeb into an open market, meaning that a Producer had to pay money from his yearly budget to other depts to get things done, studio time, OB vehicles, records from the record library, even pronunciation Unit! All the money was "virtual" of course, but beware going over budget!
Completely ludicrous idea I know, but it meant cutbacks for all programme makers, and stifled creativity.
At the same time it was decided that a percentage of programmes had to farmed off to the independent sector.
Jim Lloyd and his producer Geoffrey Hewitt, were coming up for retirement, and therefore Smooth Operations took over the Folk and Country slots on Radio 2.
But, they still had to pay for any BBC equipment they used, (Hard Cash this time), and although I recorded the Ham for a week in 1998, it was deemed to be too expensive to continue.
They still tried to cover parts of Sidmouth for a couple more years using (I think) an ex Radio York transit van, and a freelance engineer, but, when the Cambridge sponsorship deal came along, they obviously felt that would have the bigger audience draw.
You always have to bear in mind that if Smooth Ops don't get listeners, they lose the franchise. Hence playing safe with the playlists on MH's show, and covering CFF.
Producer Choice at the Beeb has been quietly dropped now, but, the Independent sector is very much still there (Feedback itself is an Indie!!)
So, while while these Indies have control over various sectors of the Beebs output, they will play safe.
You may ask why then the minority sations on digital?
1 Xtra, BBC7 (speech based), The Asian network?
Partly to help push digital along, and partly as a sop to the government, saying that we are fulfilling are public service remit, by catering for the black and asian communities.
Before we get a Folk station, they have got to cater for a Muslim network first (Don't think thats very likely in the circs)
Anyway until analogue switch off, there isn't enough bandwidth to go around.
Enough ramblings for now, but, I hope all this helps a bit
Cheers Ralph