Message-ID: <4BBCBEEB.7010706@charter.net>
Date: Wed, 07 Apr 2010 13:20:43 -0400
From: John Andrews <w1tag@charter.net>
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References: <4BB13167.3080404@telus.net>, <4BBA4F6A.9840.F1BA72@mike.dennison.ntlworld.com>, <4BBACEA6.4060703@telus.net> <4BBCB626.30059.18824AC@mike.dennison.ntlworld.com> <004201cad674$7533cd40$6d01a8c0@DELL4>
In-Reply-To: <004201cad674$7533cd40$6d01a8c0@DELL4>
Subject: Re: LF: VE7TIL Grabber and DCF39 Monitor back online
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One other constraint over here -- during the rare periods that CFH is 
running on 137.000, weak signal reception would be tough within +/- 300 Hz.

John A.

On 4/7/2010 1:04 PM, jrusgrove@comcast.net wrote:
> Mike
>
> Several hundred Hz separation between the W-E and E-W T/A windows would
> be nice - the old 136.318 / 137.777 worked well. Since the EU stations
> have abandoned 136.318 and moved to 137.777 it has been impossible to
> receive them here in the northeast US due to local activity. This has
> been pointed out over the past few years...to almost no avail.
>
> I'd suggest windows separation such that an average cw filter can
> separate the two. Would sure be nice to get back to looking for EU
> stations on 137 kHz!
>
> Jay W1VD WD2XNS WE2XGR/2
>
>
> ----- Original Message ----- From: "Mike Dennison"
> <mike.dennison@ntlworld.com>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Wednesday, April 07, 2010 11:43 AM
> Subject: Re: LF: VE7TIL Grabber and DCF39 Monitor back online
>
>
>> 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/
>>> >>>>
>>> >>>>
>>> >>>>
>>> >>>>
>>> >>>>
>>> >>>>
>>> >>>>
>>> >>>
>>> >>>
>>> >>>
>>> >>>
>>> >>
>>> >
>>> >
>>> >
>>> >
>>> >
>>>
>>>
>>
>>
>>
>
>
>