Fine wire coil

Self supporting telemetry receiver coil has 2150 turns of #50 copper wire with a footprint of 2. 0 mm x 3. 1 mm , ID = 0. 6 mm

Inside diameters can be made down to 0. 25 mm !

Wire diameter is 0. 025 mm ; one thousandth of an inch (0. 001") . That's about 4 times smaller than a human hair!