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Date: Mon, 30 Mar 2015 20:05:25 -0400
From: John Andrews <w1tag@charter.net>
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Subject: Re: LF: Dot and Dashes -  PLC noise?
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Laurence,

Interesting. The meters in this town (municipal power company) would not 
likely be the culprits, but the Worcester city line is about 1/2km away. 
That's National Grid territory, and they have begun using signalling 
meters.

John, W1TAG

On 3/30/2015 6:22 PM, Laurence KL7 L wrote:
> We get these here too - most of the dots and dashes appear at repetitive
> times every day - related to (mostly!) power meter "Turtles" in peoples
> meters which inject signals back to the local substation across the
> 110/240/7.5Kw transformers - it used to be horrid at 137kHZ  - and I
> managed to get the electrical utility to revert back a manual reading
> meter at home-  and then installed a whole house RF filter ( 2 x 220A)
> on incoming supply which helped a little more -
>
>    I still get the interference but its a lot better, that and choking
> the incoming Cable tv cable outside in the roadside podium with a large
> "J" ferrite with 15T - that helped clear up a load of VLF noise too -
> Cant fix the fenceless dog interference yet... :-(
>
> Unless its Aliens again....
>
> Laurence KL7L We2XPQ etc
>
>
>
>  > Date: Mon, 30 Mar 2015 18:00:44 -0400
>  > From: w1tag@charter.net
>  > To: rsgb_lf_group@blacksheep.org
>  > Subject: Re: LF: LF tonite
>  >
>  > Markus,
>  >
>  > > Wonder what the little dash below Stefan's "F" was... possibly
> local QRM
>  > > from some MFSK PLC system? We sometimes seem to find a number of
>  > > unexplained scattered dashes on North American QRSS spectrograms.
>  >
>  > I watched the entire band for a while this afternoon, and homed in on
>  > the 136.552 kHz frequency range below, after seeing some "dash"
>  > activity. Interesting.
>  >
>  > John, W1TAG