I figured if the TX power was high enough, the return power would be higher. Although the card might have a limit to how much it'll return. I can make a helical antenna for high directional gain. It doesn't have to be 50 meters, but even something like 5-10 meters would be good. It's not just a card, but a whole wallet with lots of different stuff in it. Thought it'd be worth a try.
Edit: I was assuming the frequency would be high, like in GHz. Looks like I can't really make a helical antenna since it is HF around 13MHz (i think).
Edit: I was assuming the frequency would be high, like in GHz. Looks like I can't really make a helical antenna since it is HF around 13MHz (i think).