Re: Electronic circuit designer

On 2007-06-21, Robert Lacoste <see-my-email-at@xxxxxxxxxxxxxx> wrote:
As others, I think you missed something : there isn't any signal in the DC
to 12Hz band on a phone line.

No, right across, but particularly in the bottom part of that spectrum is
the hook signalling, and pulse dialing, and In the upper parts there's
probably noise from the start/stop of the ring signal.

May I suggest a first zero cost step : why not
connecting a PC sound card input to your phone line, may be just with a
microphone, and analyzing the sound with a standard PC-based spectrum
analyzer software ?

A microphone won't couple 12Hz and below to a soundcard well.

Bye.
Jasen
.