I think this was ok ‘back in the day’ of analogue radio but not with digital due to the time lag.
Note: What is now the point of the Greenwich time pips with regard to digital radio? I’ve had Radio Two on both of my house radios, one on FM the other DAB. The pips on DAB can be 30-45 seconds behind.
In my experience, the differences are as follows;
if fm is regarded as the nearest to UCT and as a reference:
1) the radio stations on DVB, (i.e. via the freeview tv service) arrive about 1 second later
2) DAB stations arrive about 2.5 - 3.0 seconds later *
3) Sounds streams arrive between 20 and 25 seconds after fm.
The latency of DVB audio, DAB and the highly compressed internet stream of the sounds service effectively mean that only fm can be used to set timepieces to better than one second accuracy wrt UCT.
DAB receivers can vary in their latency by over a second according to the chips et and processing that they embody
As an aside, DVB TV can also vary, the SD channels delay the same as the sound only services (see 2) above), on HD DVB2 channels with their more advanced compression, the delay is about one extra second.