Bare wire inductor

[eeh]

Hi,

I have seen some RF transmitters (315MHz) PCB that there are some
inductor components which uses bare wires of 2.5 turns and 3mm
diameter. What are their functions? I have calculated the inductance to
be 13nH which is quite small.
Thanks!

 

[Bob Monsen]

Hi,

I have seen some RF transmitters (315MHz) PCB that there are some
inductor components which uses bare wires of 2.5 turns and 3mm
diameter. What are their functions? I have calculated the inductance to
be 13nH which is quite small.
Thanks!

If you build a tank out of that inductor, and a cap of 20pF, you have a
resonance frequency around 315MHz.

f = 1/(2.pi.sqrt(L*C))