Game clock after team A 1st down

[slasc]

Just to be sure...

A is awarded a first down, the ball carrier finishing between the hashmarks. The game clock is stopped, and starts again only after the R has blown his whistle. Correct?

Because several officials of my federation make the clock start when the ball is put on the ground by the U...

[zebra99]

correct - R's whistle and wind signal - which in most cases would be almost simultaneous with U putting the ball down.  And in some cases maybe even slightly before - game all but over, no hurry by offense, lopsided score, etc.

[Kalle]

No whistle as the 40 second clock is running, right?

[Magician]

No whistle as the 40 second clock is running, right?

There might be a quick toot with the wind but I don't think it's required.

[Rulesman]

No whistle as the 40 second clock is running, right?

I keep hearing that depends on the preference of your supervisor.

[slasc]

The second example of the NCAA 2012 #1 Bulletin is pretty clear. And that's why I use this routine now :

Marking Ball Ready For Play
2.    Late in the second or fourth quarter ball carrier A22 (a) is tackled in the field of
play beyond the line to gain; (b) runs out of bounds, either beyond or short of the line to
gain. In both (a) and (b) the game clock reads 2:35 when the ball is declared dead.
RULING:  In  both  (a) and  (b)  the  game  clock  is stopped,  and after the ball  is declared
dead the 40-second clock begins its countdown. When the officials have placed the ball
on the ground and moved away at the Referee’s direction, the Referee declares the ball
ready for play by blowing his whistle while giving the wind-the-clock signal. (3-3-2-e-1
and -3

[bossman72]

Just to be sure...

A is awarded a first down, the ball carrier finishing between the hashmarks. The game clock is stopped, and starts again only after the R has blown his whistle. Correct?

Because several officials of my federation make the clock start when the ball is put on the ground by the U...

When I work R, I like to wind the clock as soon as the U puts the ball down.  But to answer your question, the clock only starts on the R's signal, not on the ball being placed on the ground.