Since $ 28=2^2\cdot 7 $, a positive integer is relatively prime with $ 28 $ if and only if it contains neither $ 2 $ nor $ 7 $ in its prime factorization. In other words, we want to count the number of integers between $ 11 $ and $ 29 $ inclusive which are divisible by neither $ 2 $ nor $ 7 $. All of the odd numbers are not divisible by 2; there are 10 such numbers. The only one of these that is divisible by 7 is 21, so there are $ 10- 1 =\boxed{9} $ numbers between 10 and 30 that are relatively prime with 28.