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, [email protected] 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"
<[email protected]>
To: <[email protected]>
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/
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>
>
>
>
>
>
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