Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w04KpVHb005881 for ; Thu, 4 Jan 2018 21:51:34 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1eXCOY-0007Bd-0m for rs_out_1@blacksheep.org; Thu, 04 Jan 2018 20:45:46 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1eXCOX-0007BU-14 for rsgb_lf_group@blacksheep.org; Thu, 04 Jan 2018 20:45:45 +0000 Received: from smtp-out-no.shaw.ca ([64.59.134.13]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eXCOS-0004sj-JQ for rsgb_lf_group@blacksheep.org; Thu, 04 Jan 2018 20:45:43 +0000 Received: from cds110.dcs.int.inet ([10.0.153.158]) by shaw.ca with ESMTP id XCONeNqv4Z8gBXCOOeDTNf; Thu, 04 Jan 2018 13:45:36 -0700 X-DKIM-Result: Domain=shaw.ca Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shaw.ca; s=s20150330; t=1515098736; bh=CEsVNrBN5jdCXcOpMt3zUtflG59OqFaFc3+U9QYYuBs=; h=Date:From:To:In-Reply-To:References:Subject; b=YDTNT5i3JcInPuN+C5exy+yWWCoWQDIKMSu6JFlfEVlSAdUOw5Dr48pMwjvfznqAU AwLOUKE8Q0MvY8X5wP/P2ETcK+HOtF1Ai6rcyxvXLOjKHwb8QfmsVzD5n1b9nGbeCh chChfCetRZg8xNhCYShadyME3lWTLRV3PjpIpkmOhOe5zQJo1glLqVTuzYW3zngBlb X+MDfJieud/lxRyVHoT+Z+l7LVd4x34Dak11/Oa3dtzHpHMLNhAu6q9OBufWgNviCH 7HacQrBDw5Hg68lgeZruEEwb1iKKNHDIjxjfcbKCEFt8MVE98cKai21pi6Fn1FEiNP LtOCBswg/NTfw== X-Authority-Analysis: v=2.2 cv=M/g9E24s c=1 sm=1 tr=0 a=waJNmSTfdSAeIyX21TZnUA==:117 a=FKkrIqjQGGEA:10 a=d_JjZ9m1VnQA:10 a=x7bEGLp0ZPQA:10 a=pGLkceISAAAA:8 a=F3M5lZpKAAAA:8 a=wV9FcBFsAAAA:8 a=_Dj-zB-qAAAA:8 a=gALWx8SoAAAA:8 a=gAsKOvVyiXFop4sn4hwA:9 a=QEXdDO2ut3YA:10 a=lvpgojwEt4_7eicMcQ8A:9 a=qkqrSXLDplcc2nOy:21 a=_W_S_7VecoQA:10 a=slCku8JSH3TyizEDQ3pD:22 a=S9tSBiJD-_FMqjcyfT7e:22 a=c-cOe7UV8MviEfHuAVEQ:22 a=NimQcH1vBxjHXADWa3Zj:22 Date: Thu, 4 Jan 2018 13:45:35 -0700 (MST) From: JACK ASKEW To: rsgb lf group Message-ID: <1944603203.95803107.1515098735558.JavaMail.zimbra@shaw.ca> In-Reply-To: References: <4d96a9d4-5f22-7650-872b-6344e9aea8e3@abelian.org> <44f8501d-9d57-2793-b33e-ee4a2e80d6a4@abelian.org> <702563436.93043973.1515019639560.JavaMail.zimbra@shaw.ca> <1117988114.95527491.1515092735528.JavaMail.zimbra@shaw.ca> MIME-Version: 1.0 X-Originating-IP: [96.54.64.165, 70.69.223.10] X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF57 (Win)/8.6.0_GA_1200) Thread-Topic: Todmorden receiver Thread-Index: kAnp7/PXiySrAZ2MB/MgU2RTrlcc2w== X-CMAE-Envelope: MS4wfI34LK6QLtySsPWC5/br1/dTePfgFNMOyjZmk4YZQlm54kZwr3+NKrcpwuJz+/YBcJu2jJz+kmP1eMW/3H0yrpTmyHvECRqptDF0jREzn4e+UBK5WyTE 48Rgu/o7EOc9jgOE+yyDcC1HTn3AOM4r8P7ab5Hhc0ni0FQL1+59qGojtzIBjeHCFTWIUhCJdJTOpw== X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Andy Nice receiver, reminds me of one I built for the NDB band 8 years ago. Maybe mine could be modified for the VLF band using the right xtal and filters. It would be best to have a GPS added to it though. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 4e28719a46cd3d69582e1b8d1c614db3 Subject: Re: LF: RE: Todmorden receiver Content-Type: multipart/alternative; boundary="----=_Part_95803106_834143563.1515098735557" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE, MAILTO_TO_SPAM_ADDR autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false ------=_Part_95803106_834143563.1515098735557 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Andy Nice receiver, reminds me of one I built for the NDB band 8 years ago. Maybe mine could be modified for the VLF band using the right xtal and filters. It would be best to have a GPS added to it though. Jack From: "Andy Talbot" To: "LineOne" Sent: Thursday, January 4, 2018 11:34:20 AM Subject: Re: LF: RE: Todmorden receiver As an alternative to SL and soundcards, if you're into building there are other solutions for ultra high stability digital receivers. http://www.g4jnt.com/Coherent_LF_Receiver.pdf gives details of a such a receiver that I have used in the past to sucessfully decode EbNaut transmissions (on 137kHz) It uses a direct downconverter from RF to 1kHz audio in a Softrock type receiver; a DDS based LO is driven from a 10MHz master reference. The 1kHz output is bandpass filtered and digitised in a PIC to give baseband I/Q channels each at 12 bit resolution at 1kHz sampling rate. The digitised samples are fed over an RS422 interface to a PC (in practice this means a USB interconnection using FTDIChip devices) GPS NMEA data is also fed into the receiver and used to timestamp the data to the PC to 1ms resolution PC Software reads the serial data and filters / decimates the digital stream to use as wanted. The beauty of using a serial RS422 format stream means any PC programming language can be used with ready made support for the COM port. If your LF to HF shack receiver is locked to the same reference, only the digitiser is needed if the receiver is used in narrow filter CW mode with the BFO / pitch at 1kHz. But note the need to pre-filter audio to the range 800 - 1200Hz so a normal SSB filter isn't suitable Andy G4JNT On 4 January 2018 at 19:05, JACK ASKEW < va7jx@shaw.ca > wrote: Thanks for the reply. I too have problems fully understanding Spectrum Lab and envy those that use it daily. But when you get to be 75 years old ones ability to absorb technical complex issues gets more problematic ;-) I have been trying to use SL to receive signals at QRSS600 but it doesn't work for me, best I can do is get QRSS120 and it's obviously just not enough for weaker signals. I guess what I don't understand is how this program you are using receives the data real time and or how to generate that data so it can be seen later using this software. 73, Jack From: "Paul Nicholson" < vlf0403@abelian.org > To: "rsgb lf group" < rsgb_lf_group@blacksheep.org > Sent: Wednesday, January 3, 2018 9:48:27 PM Subject: Re: LF: RE: Todmorden receiver > Is that software you use for the spectrum plot display > available on line? Easy, it is all in your browser. It is all html and javascript, and it is not compiled or minified. Just save the page to you local drive. Perhaps others can use it? I try to keep the code simple and tidy to encourage that. It is necessary to provide spectrum data on your web server in the right format. I'll document the simple format and how to generate the data. -- Paul Nicholson -- ------=_Part_95803106_834143563.1515098735557 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Andy
Nice receiver, reminds m= e of one I built for the NDB band 8 years ago.  Maybe mine could be mo= dified for the VLF band using the right xtal and filters.
It would be best to have a GPS added to it though.

Jack


From: "Andy Talbot" <andy.g4jnt@gmail.com>
To: "= LineOne" <rsgb_lf_group@blacksheep.org>
Sent: Thursday, Jan= uary 4, 2018 11:34:20 AM
Subject: Re: LF: RE: Todmorden receiver<= br>

As an al= ternative to SL and soundcards, if you're into building there are other sol= utions for ultra high stability digital receivers.
http://www.g4jn= t.com/Coherent_LF_Receiver.pdf  gives details of a such a receiver= that I have used in the past to sucessfully decode EbNaut transmissions (o= n 137kHz)

It uses a direct downconverter from RF  to= 1kHz audio in a Softrock type receiver;  a DDS based LO is driven fro= m a 10MHz master reference.  The 1kHz output is bandpass filtered and = digitised in a PIC to give baseband I/Q channels each at 12 bit resolution = at 1kHz sampling rate.   The digitised samples are fed over an RS= 422 interface to a PC (in practice this means a USB interconnection using F= TDIChip devices)    GPS NMEA data is also fed into the receiver a= nd used to timestamp the data to the PC to 1ms resolution

PC = Software reads the serial data and filters / decimates the digital stream t= o use as wanted.   The beauty of using a serial RS422 format stre= am means any PC programming language can be used with ready made support fo= r the COM port.

If your LF to HF shack receiver is locked to = the same reference, only the digitiser is needed if the receiver is used in= narrow filter CW mode with the BFO / pitch at 1kHz.   But note t= he need to pre-filter audio to the range 800 - 1200Hz so a normal SSB filte= r isn't suitable

Andy  G4JNT

On 4 January 2018 at 19:05, JACK = ASKEW <va7jx@shaw.ca> wrote:
<= div>
Thanks for the reply.  I too have problems fully unde= rstanding Spectrum Lab and envy those that use it daily.  But when you= get to be 75 years old ones ability to absorb technical complex issues get= s more problematic ;-)    I have been trying to use SL to receive= signals at QRSS600 but it doesn't work for me, best I can do is get QRSS12= 0 and it's obviously just not enough for weaker signals.  I guess what= I don't understand is how this program you are using receives the data rea= l time and or how to generate that data so it can be seen later using this = software.

73, Jack  

From: "Paul Nicholson" <<= a href=3D"mailto:vlf0403@abelian.org" target=3D"_blank">vlf0403@abelian.org= >
To: "rsgb lf group" <rsgb_lf_group@blacksheep.org>
<= /span>Sent: Wednesday, January 3, 2018 9:48:27 PMSubject: Re: LF: RE: Todmorden receiver

 > Is that software you use for the spectrum = plot display
 > available on line?

Easy, it is all in you= r browser.  It is all html and
javascript, and it is not compiled o= r minified.

Just save the page to you local drive.

Perhaps ot= hers can use it?  I try to keep the code simple
and tidy to encoura= ge that.   It is necessary to provide
spectrum data on your web ser= ver in the right format.  I'll
document the simple format and how t= o generate the data.

--
Paul Nicholson
--

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