>
> Why don't you calculate the integral:
>                    T
>                  /  2         1/2
>      ( 1/(2T) * / x  (t) dt )
>                /
>             -T
> You can approximate this integral with a sum. The T is a multiple of one
>  period.There may be some problems with the root but you could solve this with
 a
> lookup table. If you want, you can store a couple of squared x:s and "recycle"
> them to create a moving rms process (You might need a lot of RAM to store
> one period of data.)
> ---------------------------
> Conny Andersson / LiTH
>
Hi Conny,

OK, this will give me an rms for all frequencies, but I would like to
know the rms for discrete frequency bands.

Maybe I should do this with an analog circuit. :(  I'm not sure if a 20 MHz
pic has the muscle to tackle this problem.

Thank you for your interest.

Yours,
--
Derrick Early
early@finite.nrl.navy.mil