We’re lucky in the UK we have the BBC, no commercials and engineering who really care about sound quality.
Whilst I no longer have FM radio I do miss it, a live concert on Radio 3 is something else.
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Why not do what HH did and snap up an 05?
It’s tempting but it’s another Fraim level which doubles the cost and I’d need to reinstate our loft aerial which I still have. We’re in a decent signal aerial high up in Poole so getting a good signal from the Isle of Wight is easy.
I could squeeze a Nat02 in next to my HiCap DR, but that could become an issue if a Supercap ends up being purchased by accident!
I still have a Creek tuner which acquits itself very well, but again the shelf issue comes back into play.
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Buggeration about shelving. That Creek was decent from memory.
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And that could easily happen, believe me; I’ve had similar accidents.
I normally blame the cat(s)…on the grounds that they can “do no wrong” and hence can get way with it, unlike some…
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Hi Mike, the upper limit is actually set by the sample frequency rate of the BBC FM distribution system, which uses 32kHz sample rate., and is low pass filtered to reject anything at 15kHz or higher. The 19kHz pilot tone uses this dead space to indicate a stereo signal along with its stereo overlays. When FM stereo distribution was setup, 32 kHz sample rate was deemed more than suitable and affordable back at that time.
The bandwidth of the BBC VHF FM stereo multiplex is 75 kHz. Interestingly the L-R signal is AM encoded into this bandwidth, with a suppressed carrier at 38kHz.
I am still really impressed at the analogue signal processing ingenuity of stereo FM.
But yes BBC web radio uses the new distribution infrastructure which uses 48kHz sample rate AAC.
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Hi Simon, what I also had in mind apart from the broadcast MPX filter is the poor frequency response of some tuners. When I was playing with radio I found HF attenuation varied across brands & models, from sharp cut-offs to slow roll downs, some went as far as the MPX 15kHz point, but many rolled of well before that, a Leak Troughline hardly made it past 10kHz (but sounded beautiful despite that).
Sure… just like in digital low pass filters, there are often benefits to using more gradual analogue filters with reduced artefacts.
I can imagine effective bandwidth to 10 kHz still sounding really pleasing… although of course there will be information being lost… the designer chooses their compromises.
However ultimately the FM signal is limited by the UK digital PCM distribution system which dates back to early 70s digital PCM audio technology.
So is this system universally used across Europe, Simon, or do other countries use different parameters? On occasions when I receive FM broadcasts from Europe under lift conditions the audio quality on some stations is impressive.
I don’t know… the details of the distribution is specific to the BBC… I suspect the analogue bandwidth plan of the stereo signal multiplex however must be common or one would need different FM receivers and decoders for different markets.
I do know the pre emphasis on FM varies between North America and Europe, but that affects eq.
Thanks yes agreed about the need for compatibility between receivers . Thanks, sorry a little off topic other than we are both using Naim tuners!
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