replacement for toroid core

[luffy]

hi is there any way i can replace toroid core from the circuit?.

there is this circuit which requires a toroid core to function. a toroid core AL=25 with 6 turns of wire. for i know i can get the inductance value required to it from this formula, n=1000[sqrt(L/AL)] . and make an air coil inductor out of that inductance value. but i am not sure if it would really work as toroid cores do since the author of the circuit says the circuit wont work without toroid core.

toroids here in our local electronic stores are not available thats why i cant provide it in my circuit.. any help with this would be much appreciated. thanks.

[PradeepKumar]

Amidon's FT-114-67 has a AL of 25 and is good up to about 50MHz. It's a bit on the large side for 6 turns, but that's nothing a hot glue gun can't fix (no pun intended).