Re: LF: RFI noise at 144 kHz exactly

[David Hine <evad_hine@yahoo.co.uk>]

Hi, I worked on large megawatt Military VLF TX's, and its certainly not that -it's probably some unfiltered cheap SMPS (TV on standby or phone charger or landline phone / charger power unit?) -very annoying, but I bet it's within a few yards from you. Tried a 'sniffer' RX? -perhaps a Long Wave  domestic portable, Regards, David

---

From: Alan Melia <alan.melia@btinternet.com>
To: rsgb_lf_group@blacksheep.org
Sent: Monday, 28 November 2016, 11:44
Subject: Re: LF: RFI noise at 144 kHz exactly

Hi John yes there are Mil stations that come up sporadically with RTTY or
GMSK. They are fairly narrow < 100Hz but the splurge that Chris reported
seemed much wider....more like interference than a genuine signal.

Alan

----- Original Message -----
From: "John Rabson" <john.rabson07@gmail.com>
To: "John Rabson" <john.rabson07@gmail.com>
Cc: <rsgb_lf_group@blacksheep.org>
Sent: Monday, November 28, 2016 10:52 AM
Subject: Re: LF: RFI noise at 144 kHz exactly


Alan,

Thank you for your suggestions regarding tracking down the QRM, but this
morning the signal on 145 kHz is no longer there. What I have noticed is
that there is now an RTTY signal on 147 kHz about the same strength here as
longwave Radio 4.

I shall continue monitoring while recommissioning my 136 kHz softrock.

John F5VLF
> On 27 Nov 2016, at 11:22, John Rabson <john.rabson07@gmail.com> wrote:
>
> I have just resumed monitoring 135 to 198 kHz and have noticed a fairly
> strong broad and constant signal on about 145 kHz which was not there last
> winter. It sounds rather like LORAN A (not C) but without the selective
> fading effects we used to get on 1.9 MHz. It appears to come from either
> north-east or south-west of my location in central Burgundy, but I have
> not yet managed to get a cross bearing.
>
> John F5VLF
>
>> On 26 Nov 2016, at 11:17, Chris Wilson <chris@chriswilson.tv> wrote:
>>
>> 26 November 2016
>>
>>
>> I have been monitoring my noise on my receivers and the big issue is a
>> constant, day and night, high level noise centred exactly on 144 kHz.
>> Is  this  a frequency that is familiar to anyone? Googling it has only
>> brought  up  comments  of  some 20kHz solar inverters talking to their
>> control  panels  down  the  mains wiring at 144 kHz, with some chatter
>> about  inverters  going  noisy  and  blanking  out their own talk back
>> frequency.
>>
>> My  next  door  but one neighbour has solar panels on his stable roof,
>> but  I  don't THINK they have an accumulator bank, they just feed back
>> into the national grid. we don't really get on too well so I am loathe
>> to approach them unless I can be sure the noise is from there.
>>
>> There's also a huge, multi acre solar farm opened about 5 miles away.
>> I would imagine some old geezer with noise near his beloved LF Ham
>> band frequency would have little impact on its operation, so i hope
>> it's not tat. Any ideas on what uses 144 kHz, and how to locate the
>> source?
>>
>> Here's  a  screen  shot  of  it as it is at the moment, but it doesn't
>> change,  day  or  night,  and its amplitiude stays pretty constant, no
>> turning  on  and off I have ever seen. My RX is on my TX aerial at the
>> moment.
>>
>> http://www.chriswilson.tv/noise.jpg
>>
>> Thanks
>>
>>
>> --
>>
>>
>> Best regards,
>> Chris  2E0ILY                          mailto:chris@chriswilson.tv
>>
>> My        part        time        LF        grabber      is      at
>> http://www.chriswilson.tv/grabber.html
>>
>>
>
> john.rabson07@gmail.com
>
> Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and
> ROBSONNE
>
>
>
>

john.rabson07@gmail.com

Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and ROBSONNE