RadioBanter - View Single Post

jasen

On 2007-03-10, John Smith I wrote:
John Smith I wrote:
wrote:

...

Do you really want to hear it, or have a "field strength
indicator"/locater?

Why not just a mike capable of "hearing" the ultrasonic freqs in
question--feeding an opamp and meter?

Pointing the mike around should lead you into the correct direction and
following the meter reading should lead you to the source(s).

Possibly can substitute a light or even a led in series with a pot and
use a visual indication of strength ...

JS

Come to think of it, wouldn't take much more to square up the sine wave
out of the opam and drop a cmos decade-divider onto that output of the
opamp and feed an ear phone with the dividers output--30,000 becomes
3,000 hz--easily "hear-able!"

only if theres no other sound present in the mic signal.

and it will give no indication of signal amplitude.