Hi Alan,
As far as I know the senders at Droitwich were Macaroni 'PULSAM's, their
trendy name for PWM modulation, and installed some 20 years ago; these
essentially are a whacking great class-D audio amp making wobbly HT
for a class-C PA. This is of course is quite different to the carrier tube / peak
tube Doherty arrangement of the animals at Orford. (Funnily enough I was
there just a couple of weeks ago; that whole place is a story waiting to be
told, isn't it?)
There might be a developing fault, and they might not be aware; it could be
worth a 'phone call to Beeb Engineering / NTL / Merlin or whomever runs
Droitwich this week. One feels like a real geeky anorak calling a 'For Real'
organisation and telling them something like that; however, a year or so ago
I went to listen to Beeb WS from Antigua on 5975 with the rig I had
'Spectran' hanging off (after looking for you lot) - lo and behold the carrier
was waving up and down by 10Hz every 45 seconds or so - synthesiser trouble.
I talked to Merlin, who arguably rightly regarded me as the worst kind of nutter,
but they did fix it.
And yes, Virginia, the Beeb do compress and EQ the snot out of everything,
just like anyone else, even Radio 4, but that shouldn't effect carrier shift.
Cheers,
Steve W3EEE
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