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

there is this circuit which requires a toroid core inductor 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.

and also, if an air core will be use with a very thin magnetic wire (AWG 30), can i use stick glue around the coil to support the coil?.

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.

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  • \$\begingroup\$ What circuit are you referring to? \$\endgroup\$
    – Andy aka
    Commented Jun 19, 2015 at 10:32
  • \$\begingroup\$ oh sorry for that, but i have added already the schematic of the circuit i was referring. the one with which in parallel with the C2. hope you can help.thanks \$\endgroup\$
    – luffy
    Commented Jun 19, 2015 at 10:45
  • \$\begingroup\$ Need to know what it is you're doing if we're going to be helpful. It could be that the inductor just won't fit where it needs to without a toroidal core. \$\endgroup\$
    – user39962
    Commented Jun 19, 2015 at 10:46
  • \$\begingroup\$ the circuit is for simple RF transmission (wireless). the schematic is the receiver circuit. \$\endgroup\$
    – luffy
    Commented Jun 19, 2015 at 10:50
  • \$\begingroup\$ the aim is that, i need to switch the LED on/off on the receiver part using the button placed on the transmitter circuit. (that is i need to build a two separate circuit, a receiver and a transmitter.) i have to switch the LED on/off wirelessly. \$\endgroup\$
    – luffy
    Commented Jun 19, 2015 at 10:56

1 Answer 1


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).


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