In 15.04 05/11/01 , Alberto wrote:

I asked my neighbors, but nobody has an ISDN line here. Just plain old analog.
But ADSL and ISDN can be found in a nearby town, about 5 km from here.
Given that today all telephone lines are buried, I am a bit skeptical about

the

possibility to receive the 17th harmonic of a signal passing in a buried line

five kilometers from here. But in my life I have learnt that often reality defies intuition and reasoning...

That's puzzling me... I remeber discussing about those spectral lines three
years ago
on the reflector!

I will try to connect a spectrum analyzer (or an RX with Argo) to my phone
lines,
and see if there is any residual of 8 kHz harmonics. My lines are analogic, but
in the central exchange they are, by sure, digitized at 8kHz rate... some
digital
buzz may leak out. Differential or common mode? who knows...

73 - Marco IK1ODO