...in many respects, we've our work "cut out for us"...
NOAA ALL HAZARDS Weather Radio transmitters operate with power from 100 to 1000 watts, with a reception range of 'city blocks' to 40 miles if everything is perfect. It often isn't for our location, hardware budget, etc. The frequency used is between Standard VHF television channels 6 and 7...and is narrow band FM with a maximum frequency deviation of 5 kHz.
Stream Quality...is so important, that several PWS team members audit the site consistently for quality and offline streams. We show you any last update times, and 'flag' any streams with issues, giving both users and providers the last observed streams status, or any station listing updates. |
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Important Notes:Once Online, Stuff will happen. Useful info and utilities at the following links:
For Stream Providers ONLY: QRA Access and Alerts | ||
— excepting a fault in a NWR transmitter — this is the responsibility of each provider.
A daily, quick, online check of your stream will prevent many 'dead' or 'disabled' feeds.
Below, see a 'quality grid' with actual NWR streams, recorded Live in July 2017.
For simplicity, and because the "BUTT" encoder is cross platform, is free, and most anyone can fire it up, we used it as our 'VU' application. The streams were monitored as PC audio directly from the NOAA Weather Radio Org main index stream player. Volume Level reference set for "optimum -4 ref" on "BUTT" using the online 'reference' track, "Look Out For Flying Pigs". (Audio compression standards are expected around 89% peak -- Pigs is encoded at 90%, and 'compares' with about a -6 to -3 db reference, depending on content.)
Additionally, as NWROrg develops 'Quality Standard' and evaluation, at the very end of the 'Station Player' list, there are Constant Level Sweep Audio references used in the quality eval for many parameters... the sweeps cover the bandwidth expected for the NOAA transmission.
Assuming we've turned on our receiver, got some NWR audio through its loudspeaker... let's enable our encoder lashup, whatever it may be, and plug it into the output jack of the receiver..., ...then we may be confronted with one or more of the below 'grid row cells':
Hover thumbnail to play examples
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That Annoying 60 Hz (or other) Audio JunkFirst, it would appear that some very, very low Line Freq Hum and Other Noise artifacts are common in many streams, and there can be many causes. First, most of us are 'piggybacking' the stream onto devices we likely use for other things, providing NOAA Weather Radio streams as volunteers, aren't professionals, and labor under individual constraints and limitations, Additionally, some esoteric junk can be inherent in a streaming platform's Sound Card limitations! Extremely low hum and noise, distortion, can be acceptable, in fact, expected. But...
Let's get rid of ANY hum / noise if possible!
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