Return-Path: Received: from mtain-dh02.r1000.mx.aol.com (mtain-dh02.r1000.mx.aol.com [172.29.65.22]) by air-de06.mail.aol.com (v126.13) with ESMTP id MAILINDE061-5eb64b5b160012f; Sat, 23 Jan 2010 10:30:09 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dh02.r1000.mx.aol.com (Internet Inbound) with ESMTP id A0A833800012C; Sat, 23 Jan 2010 10:30:06 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NYhvC-00064o-Un for rs_out_1@blacksheep.org; Sat, 23 Jan 2010 15:29:10 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NYhvC-00064f-6a for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 15:29:10 +0000 Received: from mail-px0-f187.google.com ([209.85.216.187]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NYhv9-00044O-40 for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 15:29:10 +0000 Received: by pxi17 with SMTP id 17so3229231pxi.30 for ; Sat, 23 Jan 2010 07:28:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=jPmI0Agax+i4Q+one5EtXK1yAuwdk966PJvmr3YQG5s=; b=p61dXmffAKzLrsCelOUikP7aUQBOG4ta47ufhjht4X2xRCHXAId5SSreUEbmj21RRI 3tSFHuecjYRgvRAoYxfWwX9UxTDuETvI2O1IUVUT/Cuj4O164ME597g+4eglLACB4LKt Pruy1DNncUXoFNxNlmXEqSFozAeycY5VjJUEY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=vH7hf4qYMDq/Ontmz5TvWdPBv8vGw+8YRCemVcd3fNNAZkCwwEkZUH2ZdZkqPAOfq5 LwBXQAMAS9UQEZYF+dN+smIH11lTa/0xXr7gbpachXjsx1MmcyIVOfiBdC6kY+pYpMfW VMYX6/gwapzXQ2SetBrqa1CR+v91rgaxKvzds= MIME-Version: 1.0 Received: by 10.141.89.20 with SMTP id r20mr3019687rvl.250.1264260537243; Sat, 23 Jan 2010 07:28:57 -0800 (PST) In-Reply-To: <9afca2641001230643s4cf01377h70165d22d325dbe1@mail.gmail.com> References: <9afca2641001230548m3538db64y92b335aa75c1dc00@mail.gmail.com> <9afca2641001230643s4cf01377h70165d22d325dbe1@mail.gmail.com> Date: Sat, 23 Jan 2010 15:28:57 +0000 X-Google-Sender-Auth: e861d01b4226357f Message-ID: <1f0624b91001230728l3ea0c2ffqa0e2913b3d45cca2@mail.gmail.com> From: Gary - G4WGT To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) 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=000e0cd13a0a39d9c0047dd6982b X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=BIZ_TLD,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: 3039ac1d41164b5b15fe0b1f X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --000e0cd13a0a39d9c0047dd6982b Content-Type: text/plain; charset=ISO-8859-1 Hi Roger, As JT4A is very similar to JT65A there is a good "Bozo's Guide to JT65A" 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. > > 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 perhaps? If > JT4A looks like offering the possibility of really weak signal 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 initially 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 documented 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 >> *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 JT65x, but >> at least it does have the options of being available in a range 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 fraction 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]. Wolf has a similar signalling >> efficiency, but unfortunately is wider, needs 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 persuaded not to >> abandon that mode, and in fact he modified the code to enhance the decoder >> routine so the wide spaced version would be decoded with the same S/N as >> JT4A. We discovered just how good the mode was, even under severe >> rainscatter conditions where each tone was spread out to 200Hz bandwidth >> (tone spacing in JT4G is 315Hz for 1kH zwide overall, so this rain scattered >> signal still had discrete tone energy). >> >> 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.rayjames.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 timing information is available to keep it synched. >> >> My beacon engine - the one that currently drives the 503.7/503.85 signals >> - can give JT4A immediately just by reprogramming the PIC. Would there be >> any interest, bearing in mind both the WSPR and "5MHz type" waveforms will >> be lost for the duration? >> >> Andy >> www.g4jnt.com >> >> This email has been scanned for damaging side-effects by the health and >> safety police, is guaranteed to contain no substances hazardous to health, >> but may contribute to dissolving the nether and polar regions >> >> >> On 23 January 2010 13:48, Roger Lapthorn wrote: >> >>> Having looked on the WSJT website there is little (no?) reference 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 >>> >>> -- >>> >>> http://g3xbm-qrp.blogspot.com/ >>> http://www.g3xbm.co.uk >>> http://www.youtube.com/user/G3XBM >>> G3XBM GQRP 1678 ISWL G11088 >>> >> >> > > > -- > > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > http://www.youtube.com/user/G3XBM > G3XBM GQRP 1678 ISWL G11088 > --000e0cd13a0a39d9c0047dd6982b Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Roger,

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


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, =A0Gary - G4WGT


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

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 perhaps? If JT4A= looks like offering the possibility of really weak signal QSOs to people= like me running flea-power then I'd like to explore the mode some mor= e and having a reliable signal to test with initially 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 <an= dy.g4jnt@googlemail.com> wrote:
AFAIK The is no 'simple guide'=A0=A0 JT4x was never originall= y going to be one of Joe's supported modes, although after our extensi= ve use=A0on uWaves it certainly=A0is now.=A0=A0 JT65x was the more popular= and documented code, being heavily used for EME on 144=A0/ 432 /=A01296MH= z,=A0 =A0with JT4x just one of those included in the WSJT suite to 'tr= y out'=A0=A0 If you download and read the WSJT=A0users guide and other= supporting files, there's=A0all you need to know to get it going is= in there.
=A0
=A0
Its still debatable as to whether JT4 is better or worse than JT65x,= but at least it does have the options of being available in a range of ba= ndwidths / tone spacings making it usable from DC to red light.=A0=A0 (Alt= hough I think I've only ever come across A, D and G being used respect= ively on LF, HF and uWaves)=A0=A0=A0 There's probably only a fraction= of a dB in it and both are, as far as I can ascertain, only a dB or two= away from the Shannon limit.=A0 [Which knocks spots off CW or any fuzzy= mode, as well as straight PSKnn=A0without error correction].=A0=A0 Wolf= has a similar signalling efficiency, but unfortunately is wider, needs a= linear TX to avoid being too wide and seems less user friendly.
=A0
A year or so ago we (the microwave community) wanted something for us= e=A0on 1.3GHz and up to 10GHz or beyond.=A0=A0JT4G, the widest spaced vari= ent of them=A0looked suitable.=A0=A0=A0 After some prompting, Joe was pers= uaded not to abandon that mode,=A0 and in fact=A0he=A0modified the code to= =A0enhance the decoder routine so the wide spaced version would be decode= d with the same S/N as JT4A.=A0=A0=A0 We discovered just how good the mode= was, even under severe rainscatter conditions where each tone was spread= out to 200Hz bandwidth (tone spacing in JT4G is 315Hz for 1kH zwide overa= ll, so this rain scattered signal still had discrete tone energy).
=A0
There are now two microwave beacons that transmit JT4G waveforms,=A0= =A0 the 10 and 2.3GHz ones in Dorset=A0 GB3SCX and GB3SCS www.scrbg.org=A0 =A0 and=A0 now GB= 3CSB on 1.3GHz from central Scotland http://www.rayjames.biz/gm4cxm/id14.html= =A0 Other will follow before long as it is quite an easy mode to gener= ate from a simple PIC keyer provided accurate timing information is availa= ble to keep it synched.=A0=A0
=A0
My beacon engine - the one that currently drives the 503.7/503.85 sig= nals -=A0can give JT4A immediately just by reprogramming the PIC.=A0=A0 Wo= uld there be any interest, bearing in mind=A0both the=A0WSPR 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 health and safety police, is guaranteed to contain no= substances hazardous to health, but may contribute to dissolving the neth= er and polar regions


On 23 January 2010 13:48, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
Having looked on th= e WSJT website there is little (no?)=A0 reference to JT4A in the help file= s. I assume it is similar to modes like JT6M which I have managed to recei= ve 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?
<= br>73s
Roger G3XBM

--
=
http://g3xbm-= qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088




--

http://g3xbm-qrp.bl= ogspot.com/
ht= tp://www.g3xbm.co.uk
http://www= .youtube.com/user/G3XBM
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088

--000e0cd13a0a39d9c0047dd6982b--