Message-ID: <001401c44e13$728e73a0$6507a8c0@Main>
From: "Alan Melia" <Alan.Melia@btinternet.com>
To: rsgb_lf_group@blacksheep.org
References: <5.2.0.9.2.20040519074411.01fa5ab8@pop.vianw.pt> <000501c44dfb$bdf38640$7a1686d4@erica> <000a01c44e11$896fc2b0$3b32f7c2@johnb5a82ea1a4>
Date: Wed, 9 Jun 2004 12:18:07 +0100
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Subject: LF: Re: Re: Re: Off Topic---QRM
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Hi John 13.55MHz rings a bell for the ISM frequency, which is the US "HiFer"
allocation as well. Most of the kit I have seen (not a lot) in the last 20
years had crystal control, but the supply is not always that well smoothed.
Alan
----- Original Message -----
From: "John Rabson" <word.factory@zetnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: 09 June 2004 12:03
Subject: LF: Re: Re: Off Topic---QRM


> 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>
> >
> >
> >
> >
> >
>