View Full Version : Re: Watching VU Meters Bounce
On Sunday, June 18, 2017 at 1:42:56 AM UTC-4, John Williamson wrote:
> On 10/06/2017 01:32, wrote:
> > Okay, I believe this is caused when mixing in the vocals. At about 10 seconds into the song, with vertical bar VU, you may notice the frequency band around 16kHz rises and remains constant. I checked, and there is a peak there! Was it always there? Probably! You think it may be caused by something else? Circa 1968, believe UK recorded...
> >
> > http://www.angelfire.com/empire/abpsp/images/sonofapreacher.mp3
> >
> > Jack
> >
> As Scott says, it will be TV scan, and if you zoom right in on the
> region, it will be at 15,625Hz, or 15,734Hz if it was recorded in the USA..
Let's see, interlaced, so 525/2 = 262.5, 60(Hz) x 262.5 (lines) = 15,750 Hz.
Guess some are retrace lines, huh?
Jack
>
> Paul Simon's "Diamonds On The Soles Of Her Shoes" has a spike at that
> frequency at about -30dB on the CD version, visible on the plot only
> because there's no other signal in that area.
>
> --
> Tciao for Now!
>
> John.
On Monday, June 19, 2017 at 4:33:11 PM UTC-4, wrote:
> On Sunday, June 18, 2017 at 1:42:56 AM UTC-4, John Williamson wrote:
> > On 10/06/2017 01:32, wrote:
> > > Okay, I believe this is caused when mixing in the vocals. At about 10 seconds into the song, with vertical bar VU, you may notice the frequency band around 16kHz rises and remains constant. I checked, and there is a peak there! Was it always there? Probably! You think it may be caused by something else? Circa 1968, believe UK recorded...
> > >
> > > http://www.angelfire.com/empire/abpsp/images/sonofapreacher.mp3
> > >
> > > Jack
> > >
> > As Scott says, it will be TV scan, and if you zoom right in on the
> > region, it will be at 15,625Hz, or 15,734Hz if it was recorded in the USA.
>
> Let's see, interlaced, so 525/2 = 262.5, 60(Hz) x 262.5 (lines) = 15,750 Hz.
> Guess some are retrace lines, huh?
>
> Jack
>
> >
> > Paul Simon's "Diamonds On The Soles Of Her Shoes" has a spike at that
> > frequency at about -30dB on the CD version, visible on the plot only
> > because there's no other signal in that area.
> >
> > --
> > Tciao for Now!
> >
> > John.
15.734 kHz for color
https://en.wikipedia.org/wiki/NTSC
m
John Williamson
June 19th 17, 10:01 PM
On 19/06/2017 21:47, wrote:
> On Monday, June 19, 2017 at 4:33:11 PM UTC-4, wrote:
>> On Sunday, June 18, 2017 at 1:42:56 AM UTC-4, John Williamson wrote:
>>> As Scott says, it will be TV scan, and if you zoom right in on the
>>> region, it will be at 15,625Hz, or 15,734Hz if it was recorded in the USA.
>>
>> Let's see, interlaced, so 525/2 = 262.5, 60(Hz) x 262.5 (lines) = 15,750 Hz.
>> Guess some are retrace lines, huh?
>>
29.97 frames per second, or 59.94 fields per second.
NTSC has not been locked to mains frequency for decades, and PAL started
locking to its own crystal reference almost as soon as it started being
used, as the local mains frequencies in both cases did not have the
required frequency stability.
> 15.734 kHz for color
> https://en.wikipedia.org/wiki/NTSC
> m
>
Only in the USofA and Japan.
Here in the UK and most of Europe, its 15,625Hz. But I posted that a
couple of replies ago....
The French do, of course, do it differently. They used to use 25 frames
per second and 819 lines when they were monochrome, changing to SECAM
(Said to stand for "Supreme Effort Contre les AMericains")with 25 FPS
and 625 lines but with a really, really weird colour encoding scheme for
colour.
--
Tciao for Now!
John.
On Monday, June 19, 2017 at 4:47:27 PM UTC-4, wrote:
> On Monday, June 19, 2017 at 4:33:11 PM UTC-4, wrote:
> > On Sunday, June 18, 2017 at 1:42:56 AM UTC-4, John Williamson wrote:
> > > On 10/06/2017 01:32, wrote:
> > > > Okay, I believe this is caused when mixing in the vocals. At about 10 seconds into the song, with vertical bar VU, you may notice the frequency band around 16kHz rises and remains constant. I checked, and there is a peak there! Was it always there? Probably! You think it may be caused by something else? Circa 1968, believe UK recorded...
> > > >
> > > > http://www.angelfire.com/empire/abpsp/images/sonofapreacher.mp3
> > > >
> > > > Jack
> > > >
> > > As Scott says, it will be TV scan, and if you zoom right in on the
> > > region, it will be at 15,625Hz, or 15,734Hz if it was recorded in the USA.
> >
> > Let's see, interlaced, so 525/2 = 262.5, 60(Hz) x 262.5 (lines) = 15,750 Hz.
> > Guess some are retrace lines, huh?
> >
> > Jack
> >
> > >
> > > Paul Simon's "Diamonds On The Soles Of Her Shoes" has a spike at that
> > > frequency at about -30dB on the CD version, visible on the plot only
> > > because there's no other signal in that area.
> > >
> > > --
> > > Tciao for Now!
> > >
> > > John.
>
>
> 15.734 kHz for color
> https://en.wikipedia.org/wiki/NTSC
> m
Tx!
Jack
On Monday, June 19, 2017 at 5:01:55 PM UTC-4, John Williamson wrote:
> On 19/06/2017 21:47, wrote:
> > On Monday, June 19, 2017 at 4:33:11 PM UTC-4, wrote:
> >> On Sunday, June 18, 2017 at 1:42:56 AM UTC-4, John Williamson wrote:
>
> >>> As Scott says, it will be TV scan, and if you zoom right in on the
> >>> region, it will be at 15,625Hz, or 15,734Hz if it was recorded in the USA.
> >>
> >> Let's see, interlaced, so 525/2 = 262.5, 60(Hz) x 262.5 (lines) = 15,750 Hz.
> >> Guess some are retrace lines, huh?
> >>
> 29.97 frames per second, or 59.94 fields per second.
>
> NTSC has not been locked to mains frequency for decades, and PAL started
> locking to its own crystal reference almost as soon as it started being
> used, as the local mains frequencies in both cases did not have the
> required frequency stability.
>
>
> > 15.734 kHz for color
> > https://en.wikipedia.org/wiki/NTSC
> > m
> >
> Only in the USofA and Japan.
>
> Here in the UK and most of Europe, its 15,625Hz. But I posted that a
> couple of replies ago....
>
> The French do, of course, do it differently. They used to use 25 frames
> per second and 819 lines when they were monochrome, changing to SECAM
> (Said to stand for "Supreme Effort Contre les AMericains")with 25 FPS
> and 625 lines but with a really, really weird colour encoding scheme for
> colour.
:-)))
PAL = Phase Alternate Line, I think. Less Phasing issues than NTSC.
Was told some farmer came up with the scan lines idea when plowing his fields.
Thanks! :-)
Jack
>
> --
> Tciao for Now!
>
> John.
geoff
June 20th 17, 12:10 AM
On 20/06/2017 9:01 AM, John Williamson wrote:
>
> The French do, of course, do it differently. They used to use 25 frames
> per second and 819 lines when they were monochrome, changing to SECAM
> (Said to stand for "Supreme Effort Contre les AMericains")with 25 FPS
> and 625 lines but with a really, really weird colour encoding scheme for
> colour.
>
Yeah, instead of RGB the frogs would feel the need for red white and blue !
geoff
vBulletin® v3.6.4, Copyright ©2000-2025, Jelsoft Enterprises Ltd.