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Message-ID: <4487F601.3040300@tele2.se>
Date: Thu, 08 Jun 2006 12:03:45 +0200
From: Johan Bodin <jbodin@tele2.se>
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To:  rsgb_lf_group@blacksheep.org
References: <NKEMLGOEKANPNJOBFBAFKECOCNAA.g4wgt@tiscali.co.uk> <009401c68a79$4bd89980$0300a8c0@lark> <001501c68a7c$b71c97c0$0300a8c0@LAPTOP>
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Subject: Re: LF: RE: BBC 198kHz
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Peter Martinez wrote:
> Checking across the LW band, most of them seem to be some fraction of a 
> Hz off.

The Danish station on 243kHz is "quite" spot on (as is their 1062kHz medium
wave TX). These transmitters are said to be checked against some national
danish standard and should be within 10E-10 or better. I am at (strong)
groundwave distance from the TX and I compared the 243 carrier against a
Shera style GPSDO a few years ago. The phase moved around slowly, just a
few degrees in many hours. The error was probably on my side because of
varying temperature, a "finite cost OCXO", and servo loop time constant
of many hours ;-)

A nice thing about the 243 carrier, as opposed to many other BC LF carriers,
is that it is not wobbled by any phase modulation.

Unfortunately, both transmitters, 243 and 1062, will go QRT permanently by
the end of the year :-(

73
Johan SM6LKM


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