[Lowfer] AC utility meter QRM on LF

[Dexter McIntyre W4DEX]

My local power utility recently replaced a 900 MHz remote reading meter 
with a new type.  The 900 MHz meter had a FCC ID and I was able to find 
all the test data on that meter when it was installed about 5 years 
ago.  The new meter has no FCC certification probably because it 
transmits it's data via PLC.  The 900 MHz meter required a drive by to 
read the power usage once a month where as this new meter transmits data 
multiple times per day.

As soon as the new meter was installed I noticed several UPS units I 
have online would switch to battery.  Then I started havening problems 
with several X-10 devices which would either toggle on or off when the 
meter sent data.  The data regularly transmits every 12 hours with what 
appears to be random minute intervals.  I have also noticed it often 
transmits at either 4 or 8 hour intervals.  The data last for about 3 
seconds.  This data appears to be very wide band or at least generating 
a lot of wide band noise when it transmits.  I have been trying to 
determine at what frequency most of the power is on but so far haven't 
been able to.  At first I thought since the X-10 units were being 
scrambled the meter might be on 120 kHz.  But we know 120 kHz will not 
pass through power distribution transformers, at least not at X-10 power 
levels.

Today with the SDR-IQ set to view 0 to 190 khz and connected to my LF 
xmit antenna I can detect what appears to be other meters also transmitting.

Picture of the SDR display which shows the approximate 3 second 
transmission:

http://w4dex.com/temp/ac_utility/utility_meter_data.jpg

Picture of the meter:

http://w4dex.com/temp/ac_utility/utility_meter_landisgry_focus.jpg

I'm afraid this will be a real nuisance when I connect my LF receive 
antennas for the winter.

Dex