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Article #616Re: HD RADIO is no worse than DAB or DRM radio
From: Robert Orban
Date: Fri, 05 Oct 2007 00:39
Date: Fri, 05 Oct 2007 00:39
27 lines
3105 bytes
3105 bytes
In article <Crqdndk7urPjlp3anZ2dnUVZ_g-dnZ2d@championbroadband.com>, me@champmail.net says... > > > >"SFTV_troy" blabbed: ><... this new receiving technique would not improve the sound >> (it would still be limited from 100-6000 hertz), but would only reduce >> interference. >> >At least in the States, AM & FM broadcasting is limited to 50 Hz to 15KHz. There is no low frequency limit for either AM or FM; 50 Hz was the minimum performance standard that would meet the now long-deleted FCC Proof of Performance measurements. The effective HF limit on FM is about 18.5 kHz; this leaves a +/- 500 Hz guard band for the stereo pilot tone. Again, 15 kHz was the minimum spec that would pass a Proof of Performance, not a limit on bandwidth. Currently, the legal FCC-mandated HF limit on AM in the US is a hair less than 10 kHz, which almost completely protects second-adjacent stations from interference. This was changed around 1990 as a result of work done by the National Radio Systems Committee (NRSC). More recent work by the NRSC has indicated that 7 kHz is probably the optimum compromise between causing interference and loss of audio quality on typical AM radios (which are down 3 dB at about 2.6 kHz). However, limiting bandwidth to 7 kHz is voluntary.
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X-Google-Thread: fb1f8,428391383e1324a5 X-Google-Thread: 10a749,428391383e1324a5 X-Google-Thread: 114aac,cd4ad6cadcf2b245 X-Google-Thread: f7d8a,cd4ad6cadcf2b245 X-Google-Attributes: gidfb1f8,gid10a749,gid114aac,gidf7d8a,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news2.google.com!news1.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!news.giganews.com.POSTED!not-for-mail NNTP-Posting-Date: Thu, 04 Oct 2007 19:37:45 -0500 Newsgroups: rec.audio.tech,rec.audio.car,rec.radio.shortwave,ba.broadcast Subject: Re: HD RADIO is no worse than DAB or DRM radio From: Robert Orban <donotreply@spamblock.com> Date: Thu, 04 Oct 2007 16:39:13 -0800 X-Newsreader: WinVN 0.99.12S (x86 32bit) References: <1191065666.205537.159420@n39g2000hsh.googlegroups.com> <1191096585.135753.167530@d55g2000hsg.googlegroups.com> <46ffb388.44729093@news.plus.net> <1191099764.677637.18050@22g2000hsm.googlegroups.com> <1191108136.459409.212620@50g2000hsm.googlegroups.com> <%vBLi.275$0I5.137@trnddc08> <1191140172.205755.136880@y42g2000hsy.googlegroups.com> <Crqdndk7urPjlp3anZ2dnUVZ_g-dnZ2d@championbroadband.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset=US-ASCII Message-ID: <KJudnWNZ2vjHGpjanZ2dnUVZ_vumnZ2d@giganews.com> Lines: 28 X-Usenet-Provider: http://www.giganews.com X-Trace: sv3-FgX7hQsPWiQhqndnE6H2XI3aPDjOC1ZM/seKEuxsTmYvYceYpKRdr1fWK7zV/yZUwglj1QV937M7J44!Iru73ZyUt6HKDPN03ZHcIlEIrBUD3VdKFZhR7d227A92YrJr71lVtkBjQYc5bjM7ZJgk8sKF1g== X-Complaints-To: abuse@giganews.com X-DMCA-Notifications: http://www.giganews.com/info/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.35