Radio speaker volume control question

[hutch]

We have a base station at our police department which is hooked up to two speakers so we can hear the radio in two different rooms. I attempted to add a volume control to each speaker by using this switch:


http://www.radioshack.com/product/index.jsp?productId=3012598


It appears this is not the right switch because you turn the volume down one "notch" and it pretty much turns the volume off, even after turning the radio volume way up. Can anyone direct to me to the correct volume control to use! (I am using two Motorola speakers commonly used with any Motorola radio!)


Thanks, Hutch