Return-Path: Received: from mtain-dc05.r1000.mx.aol.com (mtain-dc05.r1000.mx.aol.com [172.29.64.133]) by air-ma04.mail.aol.com (v129.4) with ESMTP id MAILINMA041-b5144d77c8d2254; Wed, 09 Mar 2011 13:37:06 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dc05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 5098F38000095; Wed, 9 Mar 2011 13:37:03 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PxOFE-00025N-CB for rs_out_1@blacksheep.org; Wed, 09 Mar 2011 18:36:24 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PxOFD-00025E-Fm for rsgb_lf_group@blacksheep.org; Wed, 09 Mar 2011 18:36:23 +0000 Received: from nm15.bullet.mail.ukl.yahoo.com ([217.146.183.189]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1PxOFD-000812-DJ for rsgb_lf_group@blacksheep.org; Wed, 09 Mar 2011 18:36:23 +0000 Received: from [217.146.183.210] by nm15.bullet.mail.ukl.yahoo.com with NNFMP; 09 Mar 2011 18:36:17 -0000 Received: from [217.146.183.172] by tm3.bullet.mail.ukl.yahoo.com with NNFMP; 09 Mar 2011 18:36:17 -0000 Received: from [127.0.0.1] by omp1013.mail.ukl.yahoo.com with NNFMP; 09 Mar 2011 18:36:17 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 721807.78726.bm@omp1013.mail.ukl.yahoo.com Received: (qmail 46597 invoked by uid 60001); 9 Mar 2011 18:36:17 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s1024; t=1299695777; bh=ohBdGMM0YLHYlsKV2rfMQM4XimP+clZ6iY7Qx/OrY7s=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=X72AR1067+bblRf2ry999sSjQHyC11gKXn0gdNUIqNNY+G8eC+yJhuMfNywsnZV4IG7To08splQN2XrIbYjzSo342B9giziEU/RjFN340gKKVX23BamDhq2KqekTjC8Gw3d2wN+Te0L+K2lNZBWeAvCiChyi5v+7eXVJ/22jFjA= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.uk; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=YRFhrAwK6AvFXilgz4Hc99SG+MtLO8zHH0c1neevNWuH3d4QlepO3py6hyqkNP7B1mdbo9QlivY4slzQ3guxGMFGHkK9/55jiykoIsBdu2Ep4JKSmpo5oavLGmqCBO4yVve0J4gWhPFi9wJ1ex1rI4opnCxIkBhTnL0ZBb8YoFU=; Message-ID: <543492.45357.qm@web28102.mail.ukl.yahoo.com> X-YMail-OSG: ljdA0cEVM1kMjnNko66PjnEC.7ZnV_QR4tups8WoF6LsZAa id8fXwVmdyUWHkDP84KUiVJoDW9eLi4LMSAJ6ve.oQM8Yo2LZkOLTYS6jaQ9 NXRtb5iYvDE22PryGaXGJvnJenqVW8L43.C_lssDasuE1OGuGgzALSJ.FW1A bEE17QLf4WNT2mffELryjl_cIrM6E9c7kN0cJpwCcObO0g4XHpFoo8CkqKHP PBRNxCRNEz845yOavVYWB0B477bc6IdryEXgGOA06i4KvkXwWcul3hFBTcCO Kf3LdT3hSGuc.W6hGOKHzRbBZbE0pCPzc.x2vtjM- Received: from [86.140.72.123] by web28102.mail.ukl.yahoo.com via HTTP; Wed, 09 Mar 2011 18:36:17 GMT X-Mailer: YahooMailRC/559 YahooMailWebService/0.8.109.292656 References: <003201cbde72$606d6090$0401a8c0@xphd97xgq27nyf> Date: Wed, 9 Mar 2011 18:36:17 +0000 (GMT) From: M0FMT To: rsgb_lf_group@blacksheep.org In-Reply-To: <003201cbde72$606d6090$0401a8c0@xphd97xgq27nyf> MIME-Version: 1.0 DomainKey-Status: good (testing) Subject: Re: LF: Re: VLF Stability and soundcard locking Content-Type: multipart/alternative; boundary="0-623598271-1299695777=:45357" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,HTML_FONT_BIG, HTML_MESSAGE 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 x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d237.2 ; domain : yahoo.co.uk DKIM : pass x-aol-sid: 3039ac1d40854d77c8cf66e0 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0-623598271-1299695777=:45357 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Mal..... =A0for my ten cents worth.=20 Without being able to add modulation or on-off keying then no QSO is takin= g=20 place.=20 I suppose you could say if there is a carrier then some one is in the shac= k but=20 that's not really a QSO. I was hoping at the start of this exercise that a CW or other PSK or simil= ar=20 real time=A0QSO could be carried out over say 10/20kms.=A0From the tests= Chris G3XIZ=20 has done the best looks like a real time QSO would only happen over a 1.5k= m path=20 cross town. Academically these tests are very interesting but I don't think IMHO they= are=20 advancing Amateur Radio Communications. It will be limited to=A0a very=20 select=A0number=A0of enthusiasts who are set up to TX and RX this type of= =20 transmission. However I will continue to try and pick up Chris 11kms away.= It=20 will help me understand how to make a sensitive receiver (something I need= =20 badly) 73 es GL Pete M0FMT IO91UX=20 ________________________________ From: mal hamilton To: rsgb_lf_group@blacksheep.org Sent: Wed, 9 March, 2011 15:55:12 Subject: LF: Re: VLF Stability and soundcard locking I agree with these comments, and have said it before. If all radio amateurs on all the other bands used this system of uh bandwi= dths=20 and day long qso's Amateur Radio would cease as a hobby. The aim should be to generate enough ERP so that=A0a qso could take place= in a=20 reasonably short time and be observed by others in say QRS 3 - 60. SWL=20 listeners/viewers could also particpate. The Dreamers band will fizzle out if=A0transmitted signals are not improve= d so=20 that a larger audience can engage in the activities.=A0 also who is going to buy a PCM2900 or similar=A0gadgets for a ONE OFF QSO= if you=20 are lucky. Again QSL reports on frequency alone are not VALID - it could be any carri= er. G3KEV =A0 ----- Original Message -----=20 >From: Andy Talbot=20 >To: rsgb_lf_group@blacksheep.org=20 >Sent: Tuesday, March 08, 2011 8:42 PM >Subject: LF: VLF Stability and soundcard locking > > >It would appear that a=A0typical soundcard isn't stable enough for VLF us= e when=20 >stations are running 1mHz bandwidth signalling, and using any locking opt= ion to=20 >other off-air signals is a bit restrictive in what software you can run. > >It may be worth looking at a custom codec driven from a locked frequency= =20 >source.=A0=A0 The PCM2900 (which costs only a few pounds=A0from Farnell,= and they=20 >supply the data sheet) is a self contained USB codec which needs only a= handful=20 >of additional components for a USB soundcard with stereo line input and= =20 >output.=A0=A0=A0=A0 For normal operation it needs a 12MHz crystal, but an= external=A012MHz=20 >source can be used which could be locked to, or derived from, a high stab= ility=20 >reference.=A0 Even a TCXO on its own=A0with typically 1ppm accuracy / sta= bility=20 >would be better than any normal 20ppm crystal > >I've built one of these codecs,=A0but have yet to confirm the resulting= sampling=20 >rate(s) are exactly what they should be.=A0 By the=A0time it has gone thr= ough USB=20 >packetising and Windows'=A0 drivers I hope full synchronicity is maintain= ed right=20 >through to the user software.=A0=A0 This may only be the case for samplin= g rates=20 >like 12000Hz - it all depends what windows does.=A0=A0 Exact conversion= is needed=20 >for this solution to be worthwhile, not just a close approximation. > >Andy >www.g4jnt.com > =20 --0-623598271-1299695777=:45357 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Mal.....  for my ten cents worth.
 
Without being able to add modulation or on-off keying then no QSO is= taking place.
 
I suppose you could say if there is a carrier then some one is in the= shack but that's not really a QSO.
 
I was hoping at the start of this exercise that a CW or other PSK or= similar real time QSO could be carried out over say 10/20kms. F= rom the tests Chris G3XIZ has done the best looks like a real time QSO wou= ld only happen over a 1.5km path cross town.
 
Academically these tests are very interesting but I don't think IMHO= they are advancing Amateur Radio Communications. It will be limited to&nb= sp;a very select number of enthusiasts who are set up to TX and= RX this type of transmission. However I will continue to try and pick up= Chris 11kms away. It will help me understand how to make a sensitive rece= iver (something I need badly)
 
73 es GL Pete M0FMT IO91UX=20

=
From: mal hamilton <g3k= evmal@talktalk.net>
To:<= /B> rsgb_lf_group@blacksheep.org
S= ent: Wed, 9 March, 2011 15:55:12
Subject: LF: Re: VLF Stability and soundcard locking<= BR>
I agree with these comments, and have said it befo= re.
If all radio amateurs on all the other bands used= this system of uh bandwidths and day long qso's Amateur Radio would cease= as a hobby.
The aim should be to generate enough ERP so that&n= bsp;a qso could take place in a reasonably short time and be observed by= others in say QRS 3 - 60. SWL listeners/viewers could also particpate.
The Dreamers band will fizzle out if transmit= ted signals are not improved so that a larger audience can engage in the= activities. 
also who is going to buy a PCM2900 or similar = ;gadgets for a ONE OFF QSO if you are lucky.
Again QSL reports on frequency alone are not VALID= - it could be any carrier.
G3KEV
 
 
----- Original Message -----
From: Andy Talbot=
Sent: Tuesday, March 08, 2011 8:42= PM
Subject: LF: VLF Stability and soun= dcard locking

It would appear that a typical soundcard isn't stable enough for= VLF use when stations are running 1mHz bandwidth signalling, and using an= y locking option to other off-air signals is a bit restrictive in what sof= tware you can run.
 
It may be worth looking at a custom codec driven from a locked freque= ncy source.   The PCM2900 (which costs only a few pounds fr= om Farnell, and they supply the data sheet) is a self contained USB codec= which needs only a handful of additional components for a USB soundcard= with stereo line input and output.     For normal ope= ration it needs a 12MHz crystal, but an external 12MHz source can be= used which could be locked to, or derived from, a high stability referenc= e.  Even a TCXO on its own with typically 1ppm accuracy / stabil= ity would be better than any normal 20ppm crystal
 
I've built one of these codecs, but have yet to confirm the resu= lting sampling rate(s) are exactly what= they should be.  By the time it has gone through USB packetisin= g and Windows'  drivers I hope full synchronicity is maintained right= through to the user software.   This may only be the case for= sampling rates like 12000Hz - it all depends what windows does. &nbs= p; Exact conversion is needed for this solution to be worthwhile, not just= a close approximation.
 
Andy
 

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