UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Modifying discriminator coil for narrow band FM.

Synchrodyne · 9th Oct 2019, 7:46 am

Indeed. Back in the day (1985 and through the 1990s), 2 of the DFW FM stations, one the PBS outlet and the other the local classical music station, used minimal compression, and I hardly ever listened to other than these when it came to FM. The commercial FM stations were very heavily compressed, and sounded noticeably louder than the other two. So I guess I was comparing NOAA weather radio with what were relatively quiet FM references. PBS had two SCAs, each taking 10%, so with 10% for the pilot tone, maximum signal audio was modulation ±52.5 kHz. And if we assume a 30% average, that’s just ±15.75 kHz.

Cheers,

9th Oct 2019, 7:46 am	#22
Synchrodyne Nonode Join Date: Jan 2009 Location: Papamoa Beach, Bay of Plenty, New Zealand Posts: 2,944	Re: Modifying discriminator coil for narrow band FM. Indeed. Back in the day (1985 and through the 1990s), 2 of the DFW FM stations, one the PBS outlet and the other the local classical music station, used minimal compression, and I hardly ever listened to other than these when it came to FM. The commercial FM stations were very heavily compressed, and sounded noticeably louder than the other two. So I guess I was comparing NOAA weather radio with what were relatively quiet FM references. PBS had two SCAs, each taking 10%, so with 10% for the pilot tone, maximum signal audio was modulation ±52.5 kHz. And if we assume a 30% average, that’s just ±15.75 kHz. Cheers,