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

Wed Jul 2 10:55:16 EDT 2014

Bill & Jay: I have a similar experience here. Suburban environment. Antenna 
less than 100ft from closest power line....single HV feeder utility lines in 
front and back of property although different power companies --- which 
could potentially make for interesting ground currents and radiated energy I 
suppose.

Wide view is 1800Hz xtal filter, narrow is 300Hz Collins. 17.200 corresponds 
to 650Hz on the waterfall...

http://i1296.photobucket.com/albums/ag19/wa3tts/17r2khz_zps8432a265.jpg

I'm hearing MSKs at 19.6, 20.9, 21.4, 22.1, 23.4, 24.0, etc.

My EWE antenna transformers (stacked BN73-202 10:5:1) have 2dB or so of 
insertion loss at 15kHz. 1dB insertion loss at 22kHz.  I may

try going to 75 material for them to reduce the insertion loss.   Can RF 
transformer IMD be an issue ?

73, Mike wa3tts

----- Original Message ----- 
From: "Bill de Carle" <ve2iq at magma.ca>
To: "Discussion of the Lowfer (US, European, & UK) and MedFer bands" 
<lowfer at mailman.qth.net>
Sent: Wednesday, July 02, 2014 9:49 AM
Subject: Re: [Lowfer] [EXTERNAL] Strange QRM here on SAQ frequency

> Hi Jay:
> I widened up the CW filter to include the six visible spectral lines - 
> audio clip here:
>
> http://www.magma.ca/~ve2iq/saq_qrm.wav
>
> This morning I shut off the main breaker at the distribution box and 
> turned off the UPS units in the radio room - no change at all to the QRM.
> It could be related to our "smart meter" - but I thought it transmitted on 
> UHF.  Must have a power source though :-)
> 73,
> Bill VE2IQ
>
>>Bill
>>
>>Can you send a short audio clip?
>>
>>Jay W1VD
>>
>>
>>----- Original Message ----- From: "Bill de Carle" <ve2iq at magma.ca>
>>To: "Discussion of the Lowfer (US, European, &UK) and MedFer bands" 
>><lowfer at mailman.qth.net>
>>Sent: Tuesday, July 01, 2014 11:45 PM
>>Subject: Re: [Lowfer] [EXTERNAL] Strange QRM here on SAQ frequency
>>
>>
>>>Thanks Laurence.  No cable TV in this area but I guess the interfering 
>>>signal could be from some kind of switching supply.  I have difficulty 
>>>with the narrow emission bandwidth and the observed frequency stability. 
>>>Local phone company runs DSL here over some distance so they must have 
>>>repeaters.  Strange how the signal disappears completely from time to 
>>>time like equipment was switched off.
>>>73,
>>>Bill VE2IQ
>>>At 08:58 PM 7/1/2014, Laurence KL7L wrote:
>>>>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
>>>> >
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