Can anyone explain the following:

I have a 9” venturi on side of fuselage – connected with a 3/8” hose, the suction gauge reads 9”.  This is too much for gyros, so I put a restrictor in the line expecting to get less vacuum – instead it goes to >10”.  This would imply that if hose was larger, vacuum would be less.

If I was to install a regulator should it go between venturi and gauges? or after gauges between them and filter?

I’m getting the feeling that a regulator is actually a “controlled leak” – adjusted by a needle-valve? True or False?

If True, it would make sense to put a controlled leak between venturi and gauges, as any dust would get sucked out of cabin without passing through gauges.

Jeff