[Lowfer] [EXTERNAL] Strange QRM here on SAQ frequency

[Howell, Laurence J]

Looks like switched mode- get the same from cable company head end amp power supplies in road side cabs - comes and goes

Laurence kl7l

> On Jul 1, 2014, at 4:45 PM, "Bill de Carle" <ve2iq at magma.ca> wrote:
> 
> Hi Everyone:
> 
> Anyone on this reflector know what could cause some very strong QRM I 
> see right on top of SAQ's 17.2 Khz frequency?  It consists of a group 
> of spectral lines spaced 120-Hz apart, centered near 17.2 Khz but 
> occupying only about 1 KHz bandwidth.  This QRM is present most of 
> the time at my QTH but oddly enough, it wasn't there on Sunday 
> morning when I got up around 4:30 am Eastern time.  Obviously it's 
> powerline-related, but as far as I know (famous last words!) it 
> doesn't seem to be coming from anything in my home.  I can even 
> disconnect the mains & run on batteries: the signal does not change, 
> so it is clearly radiated, not conducted through the power line.  The 
> amplitudes of the individual spectral lines vary slowly (cycling over 
> perhaps 20 seconds), seemingly at random.  I live in a rural 
> neighborhood and there are some electric fences around.  What bugs me 
> is why at 17.2 Khz?  Have you seen this signature before?  Here's a 
> screenshot showing what it looks like:
> 
> http://www.magma.ca/~ve2iq/saq_qrm.gif
> 
> Any ideas would be much appreciated.
> 73,
> Bill VE2IQ
> 
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> Post must be less than 50KB total for message plus attachment!
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html