7C46a and 7C46b movements... Any difference?

HI All,

I have collected a couple of movement shots of the 7C46 that powers the SBBN007 and SBBN011.

This one shows the 7C46a:


This one posted the other day (bu TinTin I think) shows a 7C46b:


I haven't cracked open my Tuna yet so I can't say whether my 7C36 is an "a" or "b"...


Here are a couple of shots of the 7C46 in a 1000m Tuna:




I wonder what is up with the "a" and "b" variants...

"Making the world a better place one Sawtooth at a time!" (Zoodles 2006)