function generator help

[diy didi]

Hi All.
I have a question relating to my signal generator. It has a sweep input. How can I use this to check frequency response of a filter. As far as I can tell, most function generators have a sweep output, not a sweep input???
HELP!!

 

[Mooly]

You can sweep the output frequency by applying a ramp input voltage from an external source. The sweep input really turns the generator into a voltage controlled oscillator.