Talk:Wobble frequency

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Conflicting claim[edit]

"DVD+RW has a constant wobble frequency, but encodes its addressing information using phase-modulated wobble addressing ..."

If it is phase modulated it cannot be a constant frequency. Phase modulation is a common method of creating a frequency modulated signal (as they are fundamentally the same thing. 109.153.242.10 (talk) 17:47, 16 December 2011 (UTC)[reply]

OK, I've solved it. Although it is a sort of phase modulation, it isn't the type in the linked article. Instead the phase of the wobble is periodically inverted (i.e. phase shifted by 180 degrees) which means that the frequency doesn't really change. The pattern of the phase reversals is used to encode the exact position on the spiral track. 109.153.242.10 (talk) 16:30, 17 December 2011 (UTC)[reply]

DVD-RAM has wobbles too, Tracks form a spiral[edit]

Land and groove are wobbled. Wobbles are not used for sector Adressing, tracks on DVD-RAM DO form a spiral. Look at the ISO/IEC 17592 or ECMA 330 ECMA 330, Paragraph Also 14.1 Track Shape 14.2 Track Path etc.: The track path shall be a continuous spiral from the inside (beginning of the Lead-in Zone) to the outside (end of the Lead-out Zone) of the disc. Wobble signal to groove and lands are detail explained in 19.5 For what the wobble is used is not explicitly explained, I suppose its for keeping the lase on the track or for regulating the speed. DVD-RAM uses ZCAV. — Preceding unsigned comment added by 91.49.147.228 (talk) 16:23, 11 March 2015 (UTC)[reply]

You have used the wrong specification. The one you quoted applies specifically to DVD-R and DVD-RW discs (and this was pointed out on Talk:DVD-RAM#RAM or no RAM when you tried to make the same claim). A DVD-RAM does not have a spiral track or lands. In fact it has almost nothing in common with the regular DVD formats other than it is an optical disc. The tracks on a DVD-RAM are annular just like a regular hard disc drive. The tracks are divided into hard sectors (you can see the sector dividers on an actual disc). Also, as you note, the supporting drives do use ZCAV since the inside tracks have fewer sectors (25) than the outside (59). There is no wobble on a DVD-RAM as the drive can derive the correct speed from the hard sectoring.
I smell a WP:SOCKPUPPET as you made the previous almost identical and incorrect claim under a specific user ID. — Preceding unsigned comment added by 86.153.135.110 (talk) 14:45, 16 May 2015 (UTC)[reply]