DIS: 'Pride & Joy' - SRV : HELP !!! - How did he do these bars... ????

Hi,

I'm trying to learn Stevie Ray Vaughan's 'Pride & Joy'.  I have the
tablature and I've hit a problem....  From the fifth bar onwards he
plays a walking bass line on the beat but with a quick dampened
'strum' on the off-beat, creating a 'un-cha, un-cha, un-cha, un-cha'
feel.

The tab I have sounds right, compared to a video of him playing it,
but this is what it says to do.....

-----x-----x-----x-----x--|-----x-----x-----x--2--0--|
-----x-----x-----x-----x--|-----x-----x-----x--2--0--|
-----x-----x-----x-----x--|-----x-----x-----x--2--0h-|
-----------x--------------|--2--------x--------------|
-----------x--2-----4-----|-----------x--2-----------|
--0-----3h-4--------------|--------3h-4--------------|

           ^                          ^
           |                          |
          ***                        ***

HOW THE HELL DO YOU MANAGE THAT !!!  I can't work out how on earth
you're supposed to hit the G (3rd fret - 6th string), then hammer it
on to the Ab *WHILST* simultaneously raking the remaining (damped!)
strings.

I've sort of half managed it physically, but the hammer on is totally
drowned out by the rake.  I've watched as carefully as the camera
angles allow, and it doesn't *look* like he's doing this, but it does
*sound* like it !

Does anyone know the way ?  There's got to be a way...... ;-)

Cheers,

Kev.