UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - BBC Radio 4 long wave reception problems etc.

paulsherwin · 5th Feb 2019, 12:16 am

The transmitted signal should stay within its transmission bandwidth even if distortion has been added earlier in the distribution chain, though I don't have an explanation and agree it's very puzzling.

To complicate things further, I understand the distribution circuit to Droitwich R4 is some arcane ISDN arrangement separate from the standard BBC Nicam circuits. This dates back to the 80s when 198kHz was still expected to have a military / civil defence role in a national emergency.

5th Feb 2019, 12:16 am	#32
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,943	Re: BBC Radio 4 198 kHz long wave sibilance. The transmitted signal should stay within its transmission bandwidth even if distortion has been added earlier in the distribution chain, though I don't have an explanation and agree it's very puzzling. To complicate things further, I understand the distribution circuit to Droitwich R4 is some arcane ISDN arrangement separate from the standard BBC Nicam circuits. This dates back to the 80s when 198kHz was still expected to have a military / civil defence role in a national emergency.