OK... It's not just me then... It is refreshing to hear someone actually mention pre/de emphasis in a discussion about reducing channel noise... THANK YOU JOE!
I thought I was loosing my mind for a while, hearing these ESSB stations. I do mostly CW, so I almost never get into the SSB portion of the band. Of late I have been running into these people, and the 4KC Plus splat they create. That was a surprise! -- Thanks and 73's, For equipment, and software setups and reviews see: www.nk7z.net for MixW support see; http://groups.yahoo.com/neo/groups/mixw/info for Dopplergram information see: http://groups.yahoo.com/neo/groups/dopplergram/info for MM-SSTV see: http://groups.yahoo.com/neo/groups/MM-SSTV/info On Sun, 2014-04-27 at 12:43 -0400, Joe Subich, W4TV wrote: > Absolutely! In addition, overly "pumped" low end simply adds hum, > rumble and IMD to the audio. Professional audio engineers have > learned to cut the low end on audio production/recording/broadcast > for a very long time except where absolutely necessary and even > then most pros use a low-cut set around 100 Hz unless they are > trying to record a bass, tuba, piano, organ, etc. with significant > program content below low C (~130 Hz) or deep C (~65 Hz). > > Very few male voices are pitched below 100 Hz - it seems to me the > lowest recorded was around 80 Hz - the fundamental range of a bass > vocalist is typically E2 (~82 Hz) to E4 (~330 Hz). Communications > quality (ITU: 2.8 KHz bandwidth) adequately covers 200 to 3000 Hz or > 100 to 2900 Hz. Even "toll grade" (2.1 to 2.4 KHz bandwidth) audio > in the old days was more than adequate for reasonable communications. > > It is particularly worth noting that the ratio of fundamental to > harmonic content in speech is quite high and systems which do not > substantially reduce the fundamental power typically sound muddy and > distorted. Broadcast systems typically use preemphasis (decreased > lows/increased highs) in transmission with corresponding deemphasis > (high frequency roll off) in reception to reduce channel noise and > improve reception. > > The infantile fascination with SSB flat from 50 Hz to 4000 Hz is > nothing more than another childish, bandwidth wasting, QRM generating > temper-tantrum from those who don't know better or don't care. > > 73, > > ... Joe, W4TV > > > On 4/27/2014 10:13 AM, David Cole wrote: > > Hi, > > > > Sorry to jump in on the thread, without an answer, but a question-- why > > the need for a low end below 200 HZ? We are not broadcast stations > > after all... Maybe I am missing something but I see zero reason for all > > of this Extended SSB, all it seems to do is cause splatter... > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
