Return-Path: Received: from mtain-mc01.r1000.mx.aol.com (mtain-mc01.r1000.mx.aol.com [172.29.96.73]) by air-dc04.mail.aol.com (v126.13) with ESMTP id MAILINDC043-86504b5b689395; Sat, 23 Jan 2010 16:22:28 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mc01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1F36F38000046; Sat, 23 Jan 2010 16:22:26 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NYnPd-0008Qu-Sp for rs_out_1@blacksheep.org; Sat, 23 Jan 2010 21:20:57 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NYnPc-0008Ql-Qu for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 21:20:56 +0000 Received: from mail-bw0-f221.google.com ([209.85.218.221]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NYnPZ-0005qR-Of for rsgb_lf_group@blacksheep.org; Sat, 23 Jan 2010 21:20:56 +0000 Received: by bwz21 with SMTP id 21so1859336bwz.4 for ; Sat, 23 Jan 2010 13:20:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=ydC8UlQAM0Lsem9McpxXYzcz+GHktDH5APD/694Q3UM=; b=HDCNmFV/Dyze9BDBK6SAe8cCzVTjrY1SNQrYe18k2SB3tDBIzBP39sNpTxDnQvfjv5 EhJ3fTU1ORzz898vOAH1TFBTi5Ps8wvShvi96hrSttvOCnX816ysHGN8phGOdozUAOXf gHtBKf+jpo9hH52jQYaqtvOOk+zBiSXqpLpFQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=H27g10nLLI0cATjn8CWyq6NGAQdoxy1v477xZMlGYAISWbqblh1x/qzFFojt0jJ4Ts 1IJD22hCp6NiB17S6iRWcHXwLMwtknwnFRMyJVMC5z6B5TjqdhfModlDVDJ7ye42HiqD DYRtUvZtwEt8K5JsCtnRd+LHkKEO1y2frypAA= MIME-Version: 1.0 Received: by 10.204.33.17 with SMTP id f17mr170079bkd.95.1264281646894; Sat, 23 Jan 2010 13:20:46 -0800 (PST) In-Reply-To: <00c501ca9c70$0d6dcb90$0401a8c0@xphd97xgq27nyf> References: <9afca2641001230548m3538db64y92b335aa75c1dc00@mail.gmail.com> <9afca2641001230643s4cf01377h70165d22d325dbe1@mail.gmail.com> <9afca2641001230852x7c870d8r3837c9b6eb60c67b@mail.gmail.com> <007201ca9c5d$3614e0f0$0401a8c0@xphd97xgq27nyf> <9afca2641001231117y223fea2cgb37f658c04708e2c@mail.gmail.com> <008e01ca9c62$d9c0a6d0$0401a8c0@xphd97xgq27nyf> <9afca2641001231215hf5edc24ve8f75cf4968600d6@mail.gmail.com> <00c501ca9c70$0d6dcb90$0401a8c0@xphd97xgq27nyf> Date: Sat, 23 Jan 2010 21:20:46 +0000 Message-ID: <9afca2641001231320g61fcb813t23d0163ee097b5ad@mail.gmail.com> From: Roger Lapthorn 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=00032555271675920f047ddb8283 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.7 required=5.0 tests=BIZ_TLD,HTML_30_40, 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: 3039ac1d60494b5b68921491 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --00032555271675920f047ddb8283 Content-Type: text/plain; charset=ISO-8859-1 So you're happy to use a PC with all its complexity to see the trace then Mal. What an APPLIANCE operator you are! 73s (and said in fun only) Roger G3XBM On 23 January 2010 21:07, mal hamilton wrote: > There cannot be a time when JT4 or WSPR will be received and not QRS > because the trace is always visible long before a data decode. There has > never been a case of an INVISIBLE trace and a data decode. The signal trace > is always VISIBLE and therefore if KEYED would convey the transmitted > message. > > G3KEV > > ----- Original Message ----- > *From:* Roger Lapthorn > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Saturday, January 23, 2010 8:15 PM > *Subject:* Re: LF: JT4A simple guide? > > Mal, > > There will be times when this may be true, but modes like WSPR and, I > expect, JT4A will get through when signals are *extremely* weak when CW > simply would not. > > Here's an idea: why not turning your ERP down to 1mW for a few weeks and > see how you get on? > > 73s > Roger G3XBM > > > > On 23 January 2010 19:32, mal hamilton wrote: > >> Obviously not reading recent postings about no decodes from >> others although the signals are visible, like I said these signals are not >> onljy visible with me but audible so why complicate matters, just send qrs >> or cw in the first place. >> Some one even mentioned DUMMIES, there are a lot of these about. Dummies >> alias Appliance operators >> The word is ill-informedtry >> g3kev >> >> >> ----- Original Message ----- >> *From:* Roger Lapthorn >> *To:* rsgb_lf_group@blacksheep.org >> *Sent:* Saturday, January 23, 2010 7:17 PM >> *Subject:* Re: LF: JT4A simple guide? >> >> Mal informed. >> >> On 23 January 2010 18:52, mal hamilton wrote: >> >>> I still see these data signals as a waste of time since had the carrier >>> been keyed I could read them 100% without having to wait for the right >>> circumstance to get a decode, no need for level 2 demodulation. >>> There are several traces now visible but only an odd >>> decode!!!!!!!!!!!!!!! Try a QRS or CW QSO if you need an immdediate report. >>> These signals are audible with me. >>> >>> >>> >>> g3kev >>> >>> >>> ----- Original Message ----- >>> *From:* Roger Lapthorn >>> *To:* rsgb_lf_group@blacksheep.org >>> *Sent:* Saturday, January 23, 2010 4:52 PM >>> *Subject:* Re: LF: JT4A simple guide? >>> >>> Ok, fully understand Andy. Jim G7NKS is sending JT4A but I'm not >>> getting any decodes yet. >>> >>> Roger G3XBM >>> >>> On 23 January 2010 16:38, Andy Talbot wrote: >>> >>>> After posting that, I realised the JT4 PIC/DDS beacon code is designed >>>> for 100% duty cycle operation, viz JT4, CW + carrier, which is a bit >>>> antisocial (certainly the wide bandwidth CW bit). And more importantly, as >>>> my PA is a low efficiency clas AB linear one - enough said... >>>> >>>> To adapt for low duty cycle would need the PIC code changing, so will >>>> put the idea on hold unles there is a real demand. For a beacon, WSPR has >>>> more to offer anyway. >>>> >>>> Incidently, WSPR and JT4 are the same mode anyway, albeit with a >>>> bandwidth change from 1.46 to 4.375Hz with a resulting 4.75dB reduction in >>>> S/N. The coding and demodulation are all the same, so this bandwidth >>>> difference should be directly detectable between the two modes. The >>>> differing message contents wont affect the efficiency, its the added error >>>> correction , sync and modulation that matters - and they use the same >>>> algorithm. >>>> >>>> Andy >>>> www.g4jnt.com >>>> >>>> >>>> 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 >>>>> >>>> >>>> >>> >>> >>> -- >>> >>> 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 >> >> > > > -- > > 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 --00032555271675920f047ddb8283 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable So you're happy to use a PC with all its complexity to see the trace= then Mal. What an APPLIANCE operator you are!=A0

73s (and said in= fun only)
Roger G3XBM

On 23 January= 2010 21:07, mal hamilton <g3kevmal@talktalk.net> wrote:
There cannot be a time when JT4 or WS= PR will be=20 received and not QRS because the trace is always visible long before a dat= a=20 decode. There has never been a case of an INVISIBLE trace and a data decod= e. The=20 signal trace is always VISIBLE and therefore if KEYED would convey the=20 transmitted message.
=A0
G3KEV
----- Original Message -----
Subject: Re: LF: JT4A simple gu= ide?

Mal,

There will be times when this may be true, bu= t=20 modes like WSPR and, I expect, JT4A will get through when signals are=20 extremely weak when CW simply would not.=A0

Here's an= idea:=20 why not turning your ERP down to 1mW for a few weeks and see how you get= on?=20

73s
Roger G3XBM



On 23 January 2010 19:32, mal hamilton <g3kevmal@talktalk.net>=20 wrote:
Obviously not reading recent post= ings about no=20 decodes=A0from others=A0although the signals are visible, like I said= =20 these signals are not onljy visible with me but audible so why complic= ate=20 matters, just send qrs or cw in the first place.
Some one even mentioned DUMMIES,= there are a=20 lot of these about. Dummies alias Appliance operators
The word is ill-informedtry
<= /font>
g3kev
=A0
-----=20 Original Message -----
From:=20 Roger Lapthorn
Sent:=20 Saturday, January 23, 2010 7:17 PM
Subject:=20 Re: LF: JT4A simple guide?

Mal informed.

On 23 January 2010 18:52, mal hamilton <g3kevmal@talktalk.net> wrote:
I still see these data signal= s as a waste=20 of time since had the carrier been keyed I could read them 100% wi= thout=20 having to wait for the right circumstance to get a decode, no need= for=20 level 2 demodulation.
There are several traces now= visible but=20 only an odd decode!!!!!!!!!!!!!!! Try a=A0QRS or CW=A0QSO =A0if=20 you need an immdediate report. These signals are audible with=20 me.
=A0
=A0
=A0
g3kev
=A0
-----=20 Original Message -----
From:=20 Roger Lapthorn
Sent:=20 Saturday, January 23, 2010 4:52 PM
Subject:=20 Re: LF: JT4A simple guide?

Ok, fully understand Andy.=A0 Jim G7NKS is sending JT4A but= =20 I'm not getting any decodes yet.

Roger G3XBM

On 23 January 2010 16:38, Andy Talbot= <andy.g4jnt@googlemail.com> wrote:
After posting that, I realised the JT4 PIC/DDS beacon cod= e is=20 designed for 100% duty cycle operation, viz JT4, CW + carrier,= which=20 is a bit antisocial (certainly the wide bandwidth CW bit).=A0= And=20 more importantly, as my PA is a low efficiency clas AB linear= one -=20 enough said...
=A0
To adapt for low duty cycle would need the PIC code chang= ing,=20 so will put the idea on hold unles there is a real=20 demand.=A0=A0 For a beacon, WSPR has more to offer=20 anyway.
=A0
Incidently, WSPR and JT4 are the same mode anyway, albeit= with=20 a bandwidth change from 1.46 to 4.375Hz=A0 with a resulting=20 4.75dB reduction in S/N.=A0 The coding and demodulation are al= l=20 the same, so this bandwidth difference should be=20 directly=A0detectable=A0between the two modes.=A0 The=20 differing message contents wont affect the efficiency, its the= added=20 error correction , sync and modulation=A0that matters - and th= ey=20 use the same algorithm.
On 23 January 2010 14:43, Roger Lap= thorn=20 <rogerlapthorn@gmail.com> wrote:
Tha= nks=20 for this help Andy.

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

73s
Roger G3XBM=20



On 23 January 2010 14:26, Andy Ta= lbot <andy.g4jnt@googlemail.com> wrote:
AFAIK The is no 'simple guide'=A0=A0 JT4x was= never=20 originally going to be one of Joe's supported modes,= although=20 after our extensive use=A0on uWaves it certainly=A0is=20 now.=A0=A0 JT65x was the more popular and documented code,= =20 being heavily used for EME on 144=A0/ 432=20 /=A01296MHz,=A0 =A0with JT4x just one of those included=20 in the WSJT suite to 'try out'=A0=A0 If you downlo= ad and=20 read the WSJT=A0users guide and other supporting files,=20 there's=A0all you need to know to get it going is in= =20 there.
=A0
=A0
Its still debatable as to whether JT4 is better or wo= rse=20 than JT65x, but at least it does have the options of being= =20 available in a range of bandwidths / tone spacings making= it=20 usable from DC to red light.=A0=A0 (Although I think I'= ;ve=20 only ever come across A, D and G being used respectively= on LF,=20 HF and uWaves)=A0=A0=A0 There's probably only a=20 fraction of a dB in it and both are, as far as I can ascer= tain,=20 only a dB or two away from the Shannon limit.=A0 [Which=20 knocks spots off CW or any fuzzy mode, as well as straight= =20 PSKnn=A0without error correction].=A0=A0 Wolf has a=20 similar signalling efficiency, but unfortunately is wider,= needs=20 a linear TX to avoid being too wide and seems less user=20 friendly.
=A0
A year or so ago we (the microwave community) wanted= =20 something for use=A0on 1.3GHz and up to 10GHz or=20 beyond.=A0=A0JT4G, the widest spaced varient of=20 them=A0looked suitable.=A0=A0=A0 After some=20 prompting, Joe was persuaded not to abandon that mode,=A0= and=20 in fact=A0he=A0modified the code to =A0enhance the=20 decoder routine so the wide spaced version would be decode= d with=20 the same S/N as JT4A.=A0=A0=A0 We discovered just how=20 good the mode was, even under severe rainscatter condition= s=20 where each tone was spread out to 200Hz bandwidth (tone sp= acing=20 in JT4G is 315Hz for 1kH zwide overall, so this rain scatt= ered=20 signal still had discrete tone energy).
=A0
There are now two microwave beacons that transmit JT4= G=20 waveforms,=A0=A0 the 10 and 2.3GHz ones in Dorset=A0=20 GB3SCX and GB3SCS www.scrbg.org=A0 =A0 and=A0 now=20 GB3CSB on 1.3GHz from central Scotland http://www.rayjames.bi= z/gm4cxm/id14.html=A0=20 Other will follow before long as it is quite an easy mode= to=20 generate from a simple PIC keyer provided accurate timing= =20 information is available to keep it synched.=A0=A0
=A0
My beacon engine - the one that currently drives the= =20 503.7/503.85 signals -=A0can give JT4A immediately just by= =20 reprogramming the PIC.=A0=A0 Would there be any interest,= =20 bearing in mind=A0both the=A0WSPR and "5MHz type"= ;=20 waveforms will be lost for the duration?

Andy
www.g4jnt.com

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


On 23 January 2010 13:48, Roger= Lapthorn=20 <rogerlapthorn@gmail.com> wrote:
Having=20 looked on the WSJT website there is little (no?)=A0=20 reference to JT4A in the help files. I assume it is simi= lar to=20 modes like JT6M which I have managed to receive in the= past on=20 50MHz but never tried TXing.

Can someone point me= in=20 the direction of a "JT4A for Dummies"= guide, or=20 something similar that I might understand,=20 please?

73s
Roger G3XBM

--

http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www= .youtube.com/user/G3XBM
G3XBM=20 =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL=20 G11088




--

http://g3xbm-qrp.blogspot.com/<= br>http://www.g3xbm.= co.uk
http://www= .youtube.com/user/G3XBM
G3XBM=20 =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL=20 G11088




--

http://g3xbm-qrp.blogspot.com/=
http://www.g3xbm.co.u= k
h= ttp://www.youtube.com/user/G3XBM
G3XBM =A0=20 =A0GQRP 1678 =A0 =A0 =A0ISWL=20 G11088


--

http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www= .youtube.com/user/G3XBM
G3XBM =A0=20 =A0GQRP 1678 =A0 =A0 =A0ISWL=20 G11088



--

http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www= .youtube.com/user/G3XBM
G3XBM=20 =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL=20 G11088



--

http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
--00032555271675920f047ddb8283--