Spyware Warrior

[hornet777]

Anyone have any experience troubleshooting/remediating telephone line noise? Links, anecdotes, and even circuits/projects welcome. I have a lot of experience in electronics, but just not telecom. It appears to be power mains harmonics that are extremely variable in amplitude and harmonic content, and is interfering with Net connection, but is also usually audible as well. I can construct filters, et cetra, but currently I'm thinking along the lines of hum-bucking coil(s): what y'all think? I should post a jpg of the scope trace. TIA.

[herbalist]

If I read this right, the telephone lines are picking up noise from something else?
My lines are underground. A while back, the outer jacket on the wire deteriorated enough to let moisture in. The sound was like a hum with a lot of extra harmonics. One other item you might want to rule out if you use them is dimmers for lights. I've had a couple of noisy ones that could make a stereo unlistenable. I'm not sure if they all work the same, but with the ones I had, the lower the lights were turned, the worse the noise got.
Rick

[hornet777]

Good grief, I've sure learned a lot in the past two days, and still digesting... Problem not fixed yet, and it may take me a couple days to collect my thoughts...

But yeah, its 60Hz (and/or harmonics) predominating in the noise component -- which shouldn't actually be there at all, since the loop is a differential-mode topology, which perhpas points to an unbalance.
No dimmers, and I know about how triacs can tear up a power, or phone line.

Still awaiting the telco tech to eliminate their part so troubleshooting can procede. More later.

[hornet777]

Well, it was determined to be a fault on the telco side, to the rest is academic, I suppose.

Did get grey boxes installed, where there were none before, so that's an improvement.

Thanks for responding; I was preparing for the worst, were it to be my responsibility for the repair, but now its up to phone company inertia, and overcoming it.