[Lowfer] AC utility meter QRM on LF

[Laurence KL7UK]

We had the same (similar?) problems in AK - the meter installed with a "Turtle" that used a PLC over wire data signal - It sent pulsing type data over the whole of LF all the time (worse around 130Khz) . Taking a portable up to the meter showed the friendly  power technician, who unplugged the turtle go "oh dear"...when the noise dissaperared - he tried another model and it got worse..."oh dear"....
 
He was a friendly soul and contacted the public relations dept and his manager and we had a three way - I told him this device was effectively stopping and interfering with an FCC licenced radio station and could we work things out? 
 
The fix was the complete removal of my turtle and now the meter is read manually once a month - there is no 900Mhz stuff out here in the boonies but there is some in Anchorage town itself. I can still see my neighbors devices but they are under the noise for teh most part and as a lot of them are some distance I dont appear to have an issue with wandering Turtles!
 
Theres a label in the meter saying the unit was removed with permission from " ....." so its not replaced.
 
Laurence Kl7 UK et al
http://ahamacav.com/Turtles.htm
 
> Date: Wed, 6 Oct 2010 13:05:45 -0400
> From: dexter.mc at gmail.com
> To: lowfer at mailman.qth.net; part15 at yahoogroups.com
> Subject: [Lowfer] AC utility meter QRM on LF
> 
> 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
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