I'm not much of a handyman; trying to make my own would probably "cost" more than $30 worth of time and aggravation.
My big concern is the whole bi-directional thing. Would that Clearstream 1 pick up well from both north and south? Say I had the reflector on the north side of the antenna (to improve how well it catches the southern US signals); would it still do a good job of picking up those nice close northern Canadian signals?