Comments on AES3 coaxial revision
[Last printing 3 June 2001]
Comments to date on Draft Revised AES-3id-xxxx
DRAFT REVISED AES information document for digital audio engineering --
Transmission of
AES3 formatted data by unbalanced coaxial cable published
2001-01-08
for comment.
Caine 2001-01-12
From: SMTP%"[email protected]" 10-JAN-2001 08:07:14.06
To: [email protected]
Subj: New fig 3 for AES-3id draft
Julian Dunn has pointed out a minor error in the eye diagram, fig 3, in
AES-3id-xxxx. I've made a replacement from a real plot of
an AES-3id signal and annotated it as required. Regards
Robin
Caine
Dunn reply 2001-01-15
From: SMTP%"[email protected]" 15-JAN-2001 12:02:51.38
Dear Mr Caine, I agree that your figure corrects an error in the figure
given in the CFC. The figure in the CFC does not show the eye diagram
correctly and would confuse the reader.
The original measurements from
which the value for Vmin was derived need to be checked in order to determine
if the error affects the quoted value of Vmin, mentioned in note 2 to clause
7.3.
Best regards
Julian Dunn
AES SC-02-02 vice chair.
Tsuchiya 2001-03-06
Fro
To: [email protected]
Subj: Comment on Draft Revised AES-3id
Greetings,
I am Yoshikazu Tsuchiya, Sony Corp. I have a comment on an
equation given in the chapter [sub-clause] A.2 of ANNEX.A (page 12).
Though an editorial error of the equation ,T=1/6,144x1/fB==0,16276usec, be
corrected , fB is not helpful parameter to understand other equations and
figures on the ANNEX. It is better to change the equation to clarify the time
unit as below after deleting 1/fB.
T=1/6,144x10-6=0,16276usec
Best
Regards
Y. Tsuchiya
Dunn reply to Tsuchiya 2001-03-08
From: SMTP%"[email protected]" 8-MAR-2001 10:29:04.81
To: AES Standards Secretariat
Subj: Re: COMMENTS ON DRAFT REVISED AES-3id-xxxx
The comment of Tsuchiya-san is editorial. Here are my suggestions for
editorial changes on that page: The parameter, T, that Tsuchiya-san
mentions, is equivalent to the unit interval, which is now defined in AES3.
The equations in the draft also show confusion of units so I recommend the
following changes:
Delete all the equations and the first paragraph on
page 12 and replace with:
(1+cos(pi.f.T))
pi.f.T
E(f) = a.(root)f + 20.log(---------------.-----------)
2 sin(pi.f.T) Where
E(f) is in dB, f is in Hz, T is in seconds, and a is in dB per root Hz.
Because the equalizer compensates cable characteristics, it is
reasonable to suppose one practical cable type to be used. The parameter
T (in seconds) is the duration of the unit interval corresponding to the
rate of transmission being used. For a 48kHz frame rate the unit interval
is 162.8ns. The parameter a (in dB Hz[-1/2]) is given by the type and
length of coaxial cable. For 1000m of 5C2V, a is 0.0085 dB Hz[-1/2]
(equivalent to 8.5 dB MHz[-1/2] as provided in table A.1).
Typesetting note: The [] indicates a font change to indicate "raised to
the power". Hz[-1/2] can also be "per root Hz" and MHz[-1/2] can be "per root
MHz", It is a matter of style.
The second paragraph and the figure on
page 12 should remain.
Best regards
Julian Dunn
Vice-chair
SC-02-02
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