I've been having a debate on resonance.

Assume a frequency of 1 MHz, and L value of 200uH, just because.
ZL =3D 1256 ohms, so we end up with a C of 127pF (close enough)

Now I'm told that to find the "best" values, I should take these values and=
 calculate Sqrt (LC) and use that value for the inductor and capacitor.

When I pull the Sqrt of (L*C) the result is in time. 159nS in this case.
I start to feel like we're doing something sketchy here, but I plug in 159u=
H and 159pF and I get another resonant pair at 1MHz with ZL or Zc =3D 1k.

Running a couple of different examples, it seems I always end up with 1k Im=
pedances.

Is this wierd trick legit?

The question I was trying to get to, is how to find the "optimum" LC pair f=
or a resonant tank circuit used as an antenna.
Ignoring parasitics for a moment, in broadcast radios one sees 365pF variab=
le caps a lot of the time. That would work out to 278uH at 500kHz
Sqrt LC here gives me 318.5nS, so I then sub 318 in as L and C numerics, an=
d I get another resonant pair at 1k ohm.







--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.