Takeout Doubles

Board 2
East Deals
N-S Vul
K 8
K 8 5 4
5 4
Q J 8 5 2
10 5 3 2
J 7 2
J 8 3 2
A 6
N
WE
S
9 6 4
A Q 10 9 3
A Q 10 9
3
A Q J 7
6
K 7 6
K 10 9 7 4
WestNorthEastSouth
  1Dbl
1223
All pass   
3 by North

South has an opening hand and tolerance for the unbid suits. North is strong enough to make a free bid, but not strong enough to bid game. North can bid 2 or 1 NT to show they have values. EW can now bid diamonds to show at least 5 hearts and 4 diamonds.
Lead is A against clubs and 7 against a heart contract.