Message-ID: <000a01c44e11$896fc2b0$3b32f7c2@johnb5a82ea1a4>
From: "John Rabson" <word.factory@zetnet.co.uk>
To: rsgb_lf_group@blacksheep.org
References: <5.2.0.9.2.20040519074411.01fa5ab8@pop.vianw.pt> <000501c44dfb$bdf38640$7a1686d4@erica>
Date: Wed, 9 Jun 2004 12:03:34 +0100
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Subject: LF: Re: Re: Off Topic---QRM
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If I recall correctly, there is an ISM allocation slightly below 14 MHz
which is used for RF heating. Some of the power oscillators I encountered
did not have a very stable centre frequency and had a rather broad signal. A
colleague from South Africa told me that he always knew when the UK was at
lunch because the background noise on 20 m down there was much reduced.

73
John G3PAI

----- Original Message ----- 
From: "g3ldo" <g3ldo@ukonline.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Wednesday, June 09, 2004 9:27 AM
Subject: LF: Re: Off Topic---QRM


> For many months now I have been experiencing a peculiar electrical
> interference. It is a rasping sound rather like a spark transmitter and
> sending something like NX in very bad morse at around 5WPM. The QRM is
> broadband centred around 14MHz and is on 24hrs a day.
> I have reported the matter to BT who hav been out to investigate but are
> unable to find the source or even say what it is.
> I have also sent a tape to David Lauder, the RSGB EMC guru but even he
does
> not know what it is.
> With my bicycle mobile I have travelled around the vicinity in a radius of
> around 3km of my QTH and find the QRM widespread with hot spots often by
> telephone line distribution poles. Most telephone poles do not carry the
> interference.
> The interference does not affect 136kHz - hence Off Topic.
>
> Regards,
> Peter, G3LDO
>
> e-mail <g3ldo@ukonline.co.uk>
>
>
>
>
>