Jose, you're right that standard F-connectors are 7/16". What you missed is that you usually have very little room to swing a wrench around on a back panel, which means re-positioning the wrench a few times.

The tool which I linked (see 'this' in my prior post) is shaped like the slitted socket described by Echoslob, with a screwdriver-like handle, and you can get a complete turn or more without re-positioning the tool, plus it reaches through the ubiquitous maze of wires.

Larry
www.fineelectricco.com