Before revision: One simple design consists of two 4.7 pF ceramic capacitors and two simple coils (4 turns of 20 AWG copper wire 6 mm long wound on a 6 mm drill bit air cored ).
After revision: One simple design consists of two 4.7 pF ceramic capacitors and two simple coils (4 turns of 20 AWG copper wire wound using a 6 mm drill bit as a formair-core inductor ).