[TangerineSDR] Power Outage Detected by VLF System

[Jonathan]

A benefit to powerline hum (radio emissions of 60Hz and harmonics radiated
by power lines) being omnipresent even in the most RF quiet locations is
that you can monitor local and regional power outages very closely with a
VLF receiver. A local power outage occurred around the vicinity of the VLF
receiver at Spring Brook Township, PA. Here is a plot of the amplitude
level of 180 Hz, a harmonic of 60 Hz, showing some power loss at ~2030UT
and completely at ~2100UT:
[image: Screen Shot 2023-12-04 at 10.07.20 PM.png]

Here you can see the hum level in greater temporal detail. What is so
impressive about this power outage is how low the hum levels got. I will be
pulling the audio file and listening to this period. Unfortunately, there
were no whistlers or dawn chorus, but hum levels this low are quite a treat:
[image: Screen Shot 2023-12-04 at 10.09.25 PM.png]

After the power outage ended, there were some interesting spikes, possibly
due to inductive inrush, then hum levels returned to normal:
[image: Screen Shot 2023-12-04 at 10.07.54 PM.png]
The VLF system was on a UPS during the power outage, so there definitely is
benefit to keep the system up and running during local power outages,
especially if the magnetosphere decides to be generous. Power grid studies
are often done using VLF receivers and the benefit is that no attachment to
the power lines are required.

Jonathan
KC3EEY
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20231205/b26b74e4/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screen Shot 2023-12-04 at 10.07.20 PM.png
Type: image/png
Size: 15883 bytes
Desc: not available
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20231205/b26b74e4/attachment-0003.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screen Shot 2023-12-04 at 10.09.25 PM.png
Type: image/png
Size: 15122 bytes
Desc: not available
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20231205/b26b74e4/attachment-0004.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screen Shot 2023-12-04 at 10.07.54 PM.png
Type: image/png
Size: 16149 bytes
Desc: not available
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20231205/b26b74e4/attachment-0005.png>