I unknowingly bought some "ultra bright" 3mm LEDs from Amazon. At "normal" LED currents, 10mA or so, they are so bright you cant even look at them, like staring at the sun. I experimented with dropping resistors and went as far as 120k @3.3v and they still emitted a usable amount of light! Do the math on that one, a handful of microamps!
My point being that Alan is correct, if you get the ultra-bright LEDs and hang a high value dropping resistor on it, I think you could connect an LED to anything, anywhere in the QDX without worries.
73, Chris - KC0TKS
