Return-Path: Received: from mtain-mb06.r1000.mx.aol.com (mtain-mb06.r1000.mx.aol.com [172.29.96.26]) by air-ma04.mail.aol.com (v126.13) with ESMTP id MAILINMA041-b5144b5b188f1; Sat, 23 Jan 2010 10:41:03 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mb06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0462E3800008A; Sat, 23 Jan 2010 10:41:01 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NYi5l-0006Ba-EL for rs_out_1@blacksheep.org; Sat, 23 Jan 2010 15:40:05 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NYi5k-0006BR-Nu for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 15:40:04 +0000 Received: from out1.ip02ir2.opaltelecom.net ([62.24.128.238]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NYi5g-00049n-WC for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 15:40:04 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AosFAKemWktZ8Y3g/2dsb2JhbAAtjUcFx3WEOwQ X-IronPort-AV: E=Sophos;i="4.49,329,1262563200"; d="scan'208,217";a="311937558" Received: from unknown (HELO xphd97xgq27nyf) ([89.241.141.224]) by out1.ip02ir2.opaltelecom.net with SMTP; 23 Jan 2010 15:39:54 +0000 Message-ID: <003101ca9c42$4ce6f720$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <9afca2641001230548m3538db64y92b335aa75c1dc00@mail.gmail.com> <9afca2641001230643s4cf01377h70165d22d325dbe1@mail.gmail.com> <1f0624b91001230728l3ea0c2ffqa0e2913b3d45cca2@mail.gmail.com> Date: Sat, 23 Jan 2010 15:39:50 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: JT4A simple guide? Content-Type: multipart/alternative; boundary="----=_NextPart_000_002E_01CA9C42.4CAB4DB0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.4 required=5.0 tests=BIZ_TLD,HTML_20_30, HTML_FONTCOLOR_UNSAFE,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-sid: 3039ac1d601a4b5b188d4a42 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_002E_01CA9C42.4CAB4DB0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Only one wspr sig present, no jt4 at present g3kev =20 ----- Original Message -----=20 From: Gary - G4WGT=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Saturday, January 23, 2010 3:28 PM Subject: Re: LF: JT4A simple guide? Hi Roger, As JT4A is very similar to JT65A there is a good "Bozo's Guide to JT= 65A" amongst many others at the following site :- http://www.pe2pe.eu/wsjt_manuals.htm I found this "Bozo's Guide" very useful to get started, The author= Andy K3UK (yes he is from the UK) self confessed "Bozo" has written= it for other Bozo's. 73, Gary - G4WGT On 23 January 2010 14:43, Roger Lapthorn = wrote: Thanks for this help Andy.=20 I'd not like to derive others of your valuable 500kHz WSPR beacon,= but could you beacon in JT4A at certain pre-arranged times or days pe= rhaps? If JT4A looks like offering the possibility of really weak sign= al QSOs to people like me running flea-power then I'd like to explore= the mode some more and having a reliable signal to test with initiall= y would be useful. I am sure there will be others who would value this= too. 73s Roger G3XBM On 23 January 2010 14:26, Andy Talbot = wrote: AFAIK The is no 'simple guide' JT4x was never originally going= to be one of Joe's supported modes, although after our extensive use= on uWaves it certainly is now. JT65x was the more popular and docum= ented code, being heavily used for EME on 144 / 432 / 1296MHz, with= JT4x just one of those included in the WSJT suite to 'try out' If= you download and read the WSJT users guide and other supporting files= , there's all you need to know to get it going is in there. http://www.physics.princeton.edu/pulsar/K1JT/WSJT_User_600.pdf= =20 http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html http://www.physics.princeton.edu/pulsar/K1JT/JT2_JT4.TXT Its still debatable as to whether JT4 is better or worse than JT= 65x, but at least it does have the options of being available in a ran= ge of bandwidths / tone spacings making it usable from DC to red light= . (Although I think I've only ever come across A, D and G being used= respectively on LF, HF and uWaves) There's probably only a fractio= n of a dB in it and both are, as far as I can ascertain, only a dB or= two away from the Shannon limit. [Which knocks spots off CW or any= fuzzy mode, as well as straight PSKnn without error correction]. Wo= lf has a similar signalling efficiency, but unfortunately is wider, ne= eds a linear TX to avoid being too wide and seems less user friendly. A year or so ago we (the microwave community) wanted something= for use on 1.3GHz and up to 10GHz or beyond. JT4G, the widest spaced= varient of them looked suitable. After some prompting, Joe was per= suaded not to abandon that mode, and in fact he modified the code to= enhance the decoder routine so the wide spaced version would be deco= ded with the same S/N as JT4A. We discovered just how good the mode= was, even under severe rainscatter conditions where each tone was spr= ead out to 200Hz bandwidth (tone spacing in JT4G is 315Hz for 1kH zwid= e overall, so this rain scattered signal still had discrete tone energ= y). There are now two microwave beacons that transmit JT4G waveforms= , the 10 and 2.3GHz ones in Dorset GB3SCX and GB3SCS www.scrbg.org= and now GB3CSB on 1.3GHz from central Scotland http://www.rayjame= s.biz/gm4cxm/id14.html Other will follow before long as it is quite= an easy mode to generate from a simple PIC keyer provided accurate ti= ming information is available to keep it synched. =20 My beacon engine - the one that currently drives the 503.7/503.8= 5 signals - can give JT4A immediately just by reprogramming the PIC.= Would there be any interest, bearing in mind both the WSPR and "5MH= z type" waveforms will be lost for the duration? Andy www.g4jnt.com This email has been scanned for damaging side-effects by the hea= lth and safety police, is guaranteed to contain no substances hazardou= s to health, but may contribute to dissolving the nether and polar reg= ions On 23 January 2010 13:48, Roger Lapthorn wrote: Having looked on the WSJT website there is little (no?) refer= ence to JT4A in the help files. I assume it is similar to modes like= JT6M which I have managed to receive in the past on 50MHz but never= tried TXing. Can someone point me in the direction of a "JT4A for Dummies"= guide, or something similar that I might understand, please? 73s Roger G3XBM --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/G3XBM G3XBM GQRP 1678 ISWL G11088 --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/G3XBM G3XBM GQRP 1678 ISWL G11088 ------=_NextPart_000_002E_01CA9C42.4CAB4DB0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Only one wspr sig present, no jt4 at= =20 present
g3kev
 
----- Original Message -----
Sent: Saturday, January 23,= 2010 3:28=20 PM
Subject: Re: LF: JT4A simple= guide?

Hi Roger,

As JT4A is very similar to JT65A there is a good "Bozo's Guide= to JT65A"=20 amongst many others at the following site :-


I found th= is "Bozo's=20 Guide" very useful to get started, The author Andy K3UK (yes he is= from the=20 UK) self confessed "Bozo" has written it for other Bozo's.

73,  Gary - G4WGT


On 23 January 2010 14:43, Roger Lapthorn <r= ogerlapthorn@gmail.com>=20 wrote:
Thanks=20 for this help Andy.

I'd not like to derive others of your= valuable=20 500kHz WSPR beacon, but could you beacon in JT4A at certain pre-ar= ranged=20 times or days perhaps? If JT4A looks like offering the possibility= of really=20 weak signal QSOs to people like me running flea-power then I'd lik= e to=20 explore the mode some more and having a reliable signal to test wi= th=20 initially would be useful. I am sure there will be others who woul= d value=20 this too.

73s
Roger G3XBM



On 23 January 2010 14:26, Andy Talbot <andy.g4jnt@googlemail.com> wrote:<= BR>
AFAIK The is no 'simple guide'   JT4x was never= originally=20 going to be one of Joe's supported modes, although after our ext= ensive=20 use on uWaves it certainly is now.   JT65x= was the=20 more popular and documented code, being heavily used for EME on= 144 /=20 432 / 1296MHz,   with JT4x just one of those incl= uded in=20 the WSJT suite to 'try out'   If you download and read= the=20 WSJT users guide and other supporting files, there's a= ll you=20 need to know to get it going is in there.
 
 
Its still debatable as to whether JT4 is better or worse th= an JT65x,=20 but at least it does have the options of being available in a ra= nge of=20 bandwidths / tone spacings making it usable from DC to red=20 light.   (Although I think I've only ever come across= A, D and G=20 being used respectively on LF, HF and uWaves)   = There's=20 probably only a fraction of a dB in it and both are, as far as= I can=20 ascertain, only a dB or two away from the Shannon limit. = [Which=20 knocks spots off CW or any fuzzy mode, as well as straight=20 PSKnn without error correction].   Wolf has a sim= ilar=20 signalling efficiency, but unfortunately is wider, needs a linea= r TX to=20 avoid being too wide and seems less user friendly.
 
A year or so ago we (the microwave community) wanted someth= ing for=20 use on 1.3GHz and up to 10GHz or beyond.  JT4G,= the widest=20 spaced varient of them looked suitable.   = After some=20 prompting, Joe was persuaded not to abandon that mode,  and= in=20 fact he modified the code to  enhance the decoder= routine=20 so the wide spaced version would be decoded with the same S/N as= =20 JT4A.    We discovered just how good the mode was= , even=20 under severe rainscatter conditions where each tone was spread= out to=20 200Hz bandwidth (tone spacing in JT4G is 315Hz for 1kH zwide ove= rall, so=20 this rain scattered signal still had discrete tone energy).
 
There are now two microwave beacons that transmit JT4G=20 waveforms,   the 10 and 2.3GHz ones in Dorset  GB= 3SCX and=20 GB3SCS www.scrbg.org    and  now GB3CSB on=20 1.3GHz from central Scotland http://www.rayjames.= biz/gm4cxm/id14.html  Other=20 will follow before long as it is quite an easy mode to generate= from a=20 simple PIC keyer provided accurate timing information is availab= le to keep=20 it synched.  
 
My beacon engine - the one that currently drives the 503.7/= 503.85=20 signals - can give JT4A immediately just by reprogramming= the=20 PIC.   Would there be any interest, bearing in mind&nb= sp;both=20 the WSPR and "5MHz type" waveforms will be lost for the=20 duration?

Andy
www.g4jnt.com

This email has been= scanned for=20 damaging side-effects by the health and safety police, is guaran= teed to=20 contain no substances hazardous to health, but may contribute to= =20 dissolving the nether and polar regions


On 23 January 2010 13:48, Roger Lapthor= n <rogerlapthorn@gmail.com> wrot= e:
Having=20 looked on the WSJT website there is little (no?)  referen= ce to JT4A=20 in the help files. I assume it is similar to modes like JT6M= which I=20 have managed to receive in the past on 50MHz but never tried= =20 TXing.

Can someone point me in the direction of a "J= T4A for=20 Dummies" guide, or something similar that I might understa= nd,=20 please?

73s
Roger G3XBM

--

http://g3xbm-qrp.blogspot.com/<= BR>http://www.g3xbm.co.uk
http://www.youtube.com/= user/G3XBM
G3XBM  =20  GQRP 1678      ISWL=20 G11088




--

http://g3xbm-qrp.blogspot.c= om/
ht= tp://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM<= BR>G3XBM  =20  GQRP 1678      ISWL=20 G11088

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