IR Emitter jack not workin

Not sure if im doin something wrong, but i tried 2 IR emmiters that i had layin around and i cant get them to work.
Are there only some that will work with the USB-UIRT. Does the jack have to be mono\stereo?
Any ideas, is it possible that the input jack on the UIRT can be bad??
Are there only some that will work with the USB-UIRT. Does the jack have to be mono\stereo?
Any ideas, is it possible that the input jack on the UIRT can be bad??