David Mulvey - KD6BZN Noise Page

ARRL - The Issue of Power-Line Noise
Power Line Noise
Radiated and Conducted Noise

Noise Source Azimuth 180 degrees. Captured on a Tektronix 6120a Real Time Spectrum Analyzer using the zero-span mode of the DPX view. MR to M1 = 8.25msec. 1/0.00825 = 121 Hz. This probably means the source signal is a 60 Hz line, because the arcing occurs twice in one wavelength, once at the top of the cycle, and again at the bottom of the cycle. This means it's probably arcing on SCE's equipment.

If this were a switching mode power supply, the group of pulses would be much closer together in time.

PRF within the pulse group was more random, but generally 0.1 to 1 msec.

SCE's initial search brought them to this house with the same noise signature.

But, I didn't find anything here. I could hear noise, but it wasn't from here.

Later, I traced it down closer to the source: Pole # 4694516E or 2025 West Milling Street. I did a foot search through 2026 West Lumber Street property with owner's permission.


Here is a different noise source (Azimuth ~ 65 degrees), but there are actually two sources shown here.
I see in red AC voltage arcing (electric company)
I think this might be a switch mode power supply in yellow

Now three sources (180, 65?, unknown?)


June 29th, 2020, the RTVI crew came out and located the source I called about located at pole #4694516E.
While they were searching, I did located an azimuth direction of another noise source.
The noise had a different signature today, getting worse. Instead of 3 or 4 pulses @ 120 Hz, it's more like 10 to 20.

They found and wrote the noise marked in red.
They didn't have time to look for the yellow @ 115 degrees azimuth.
And the green was new and wierd, @ 160 degrees azimuth.

Video... Watch how the lines I marked in green above move back and forth. It's wierd and I don't know what it is.