jrhees wrote:Some things you can check:
1.... Plug a set of stereo headphones into the USB-UIRT and transmit an IR signal. You will hear it on the headphones...
2. Some plugi-in emitters are not visible, so you'll only be able to test them with the device you're trying to control. ...
-Jon
Re:1, one might note that it is not necessary to actually put the phones in/on your ear, as the sound is plenty loud (as I found the hard way

)
Re:2, if you get sound but still not the control of device you expect, you can extend your diagnosis by visually confirming a working (or non-working) IR emitter using many models of digital camera or camcorder, as they are actually sensitive into the near IR - just turn on the cam, point the lens at the emitter, and watch in the viewfinder. I tried four cams and 3 of the 4 showed the IR flashing in their viewfinder, even though (of course) this is not visible to the naked eye when looking directly at the emitter (the fourth was a newer Sony camcorder, and when I turned on Nightshot mode it worked too, making 4 for 4). More hints: try it with the built-in emitter(s) first to verify your cam works; and with some cam/plugin emitter combinations, you need to get the cam pretty close to the emitter to see it flash, the plug ins are not nearly as bright as the builtins and this may be further reduced because there may be some degree of filtering built into the cam hw or sw.
FWIW,
-tom-