Question:
Since I’m trying to chase multiple noises all mixed together, the Radar
Engineers Model 243 would be cool to have, but it cost ~ $6,500. I’m thinking
of buying an SDRPlay or HackRF product instead, to display frequency tuned zero
span analysis. I haven’t seen a video yet, but do either of these devices
(with available software) perform zero-span sweeps?
RFI Search Update:
The SCE RTVI guys came out a second time today and located, I believe, the
correct source of noise this time (a lightning arrester). This is the 3rd
lightning arrester to start leaking (arcing to ground) in the past 10 years or
so. They wrote it up, priority 2, should be fixed in 90 days or less.
At the bottom of this page: http://www.mulveyware.com/noise/ is a screenshot
and video of the noise on a spectrum analyzer (time domain).
The video and screenshot on the web page depicts at least three noise sources.
The two highest noises are obvious to me (AC line arcing).
The 3rd and lowest amplitude noise source is weird to me. I marked the
screenshot (not the video) in green.
I’ll have to call SCE later when I locate these other two sources.
Dave
From: kd6bzn@gmail.com <kd6bzn@gmail.com>
Sent: Monday, June 15, 2020 3:56 PM
To: rfi@contesting.com
Subject: Southern California Edison (RTVI Dept)
I had a good experience with Southern California Edison. SCE contracts the
Radio TV Interference (RTVI department) duties to two guys (electrician
contractors) Steve and Ben.
The first hurdle is to call the main line, get through the menu and talk to a
real person.
The 2nd hurdle is to tell the receptionist that we have "Interference" probably
from the SCE and we need an appointment with the "RTVI department". They will
likely not know what you are talking about, they may create a ticket, but refer
to the EMF department, or not create a ticket because they do not understand,
please hold while I talk to my manager...
Once I had acknowledgement that a ticket was being created and it was
concerning the "RTVI" department, Steve called me about a week later and set up
an appointment with me.
Steve and Ben drove two hours to my location and connected their
RadarEngineers.com Model 243 receiver (tuned O-scope or zero-span spectrum
analyzer) to my antenna. I showed them the noise and they recorded it. They
left the house, returned 2 hours later with a location. Unfortunately for me,
it wasn't a power line, rather, noise from someone's house 600 feet away. I
felt a little embarrassed that I didn't do due diligence and perform a DF hunt
before they were called. But, they said this is our job... Next time, I'll do
better.
There are a group of ~4 pulses, and each group of 4 pulses repeat every 8.25
ms. 1/0.00825 = 120 Hz.
So, something is arching at the peak of the wave envelope (bottom and top).
The PRF is 120 Hz (60Hz X 2), so it's likely a AC Line accessory on the
property. I have to go knock on the door, pray for me.
freq (MHz)
Measured Signal (dBm) @ ~500 KHz BW
spreading loss
distance (feet)
Antenna Gain
Calculated dBm (EIRP)
watts
millivolts
50
-54
-51.80
608
12.8
-15.00
3.16577E-05
0.031657697
Pictures:
http://www.mulveyware.com/noise/index.html
Dave
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