From: "Mike Dennison" <mike.dennison@ntlworld.com>
To: rsgb_lf_group@blacksheep.org
Date: Wed, 07 Apr 2010 16:43:18 +0100
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Message-ID: <4BBCB626.30059.18824AC@mike.dennison.ntlworld.com>
In-reply-to: <4BBACEA6.4060703@telus.net>
References: <4BB13167.3080404@telus.net>, <4BBA4F6A.9840.F1BA72@mike.dennison.ntlworld.com>, <4BBACEA6.4060703@telus.net>
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Subject: Re: LF: VE7TIL Grabber and DCF39 Monitor back online
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Scott,

I do not have direct experience of running a grabber, but it seems to 
me that your main difficulty is that, even with a SSB bandwidth on 
your LF receiver, you cannot cover DCF39 and the Eu DX window at the 
same time.

The window at 136.318kHz was chosen to facilitate transatlantic tests 
and two-way QSOs so that the west-east traffic around 137.777kHz did 
not clash with east-west traffic. As I recall, there were QRM issues 
in Canada or the USA which meant that this was optimum. I do not know 
whether these are still relevant.

I suggest an alternative west-east DX window just below the QRSS3 
part of the band, ie around 137.650kHz. Provided this is not used for 
daytime transmissions when QRSS3 activity is expected, it should not 
cause QRM to other users. I would still suggest using the lower part 
of the band for skeds.

This would enable you and others to add an Argo window that is within 
the receiver's passband, but avoids the need for Eu stations to QRM 
the 137.777 area in order to check reception on most grabbers.

Does this help?

What to other users of 137kHz think?

Mike
====



> If you or anyone can assist me in getting the equipment or expertise
> to get this setup I can commit to have it operational from a low noise
> site for the next DX season.
> 
> I just welcomed my first child within the last year to the world so
> time is limited but my passion for LF is GREAT ;-)
> 
> 73 Scott
> 
> 
> 
> 
> 
> 
> Mike Dennison wrote:
> > OK, all understood. Thanks for considering the idea.
> >
> > 73 de Mike
> > ========
> >
> >   
> >> Unfortunately as the main LF RX is tuned to allow reception of the
> >> upper end of the band 137778ish and DCF39 the EU DX window is not
> >> within my passband.
> >>
> >> I hope to have a SDR online sometime in the future which would
> >> resolve this.
> >>
> >> 73,
> >> Scott
> >>
> >>
> >>
> >>
> >> Mike Dennison wrote:
> >>     
> >>> This is good news, Scott. Is there any chance of one of your
> >>> grabbers being tuned to the EU DX Tx window of 136.318kHz?
> >>>
> >>> Mike. G3XDV
> >>> ==========  
> >>>
> >>>   
> >>>       
> >>>> I'm pleased to report the noise problem has been resolved and
> >>>> most of the renovations here are complete.  The 2200m grabber and
> >>>> DCF39 monitor are back online.
> >>>>
> >>>> 73 Scott
> >>>> VE7TIL
> >>>> http://www3.telus.net/sthed/argo/
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>     
> >>>>         
> >>>
> >>>
> >>>   
> >>>       
> >>     
> >
> >
> >
> >
> >   
> 
>