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 x07DmeGF007037 for ; Mon, 7 Jan 2019 14:48:41 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ggV8A-0000b9-B7 for rs_out_1@blacksheep.org; Mon, 07 Jan 2019 13:39:50 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ggV7x-0000ay-6A for rsgb_lf_group@blacksheep.org; Mon, 07 Jan 2019 13:39:37 +0000 Received: from mail-ed1-x535.google.com ([2a00:1450:4864:20::535]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1ggV7s-0002bp-TD for rsgb_lf_group@blacksheep.org; Mon, 07 Jan 2019 13:39:36 +0000 Received: by mail-ed1-x535.google.com with SMTP id b3so926347ede.1 for ; Mon, 07 Jan 2019 05:39:32 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=hZQ/ckreIP9dSKgmuC66Oyhrq3F/EhqZDCh1bh+VQus=; b=nBoRmvIQ8gIsTTz3qD3jjPoeSq8G53Ua1c33FF/a7thzLMQVvJJ7Au/4oSGF4yerU+ KIq1B+0oa8IdmMJ/BMvR0wq+GgQam7BOLmidXVfResFNhx7KJE4fdvOuyIRQZEzB0V8n 47TFE/ZOTFcNDPy8GaiJAaTEMFSU7DHDWC4xJv9bTo7RnMsTlhlhxCFRn2ofi6PKmQBw k6tD1T6aTjaR2EcoQWBu22Nhp1EAluk3TCP3D5BdhjwwTArC6LLS/ndXUKfMfZpm1ELE Pky6XrefHOTHTitHo3VdWhLCKvOu7rDucQ3rOVV9WFvQ/IAp3Y9PASJQCTE1Xyk/O944 08qA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=hZQ/ckreIP9dSKgmuC66Oyhrq3F/EhqZDCh1bh+VQus=; b=RkekpySrmNLXGlJijPx1GG13IGPTjRZ9nd98r4aZtg7l5JtxMsgOe0AbVXu4oE0FPM YzoqAFlzQS3iyABg9kPPqHlvILClBagyW/4HTE/O2CBLKyzSQxp53WU0YkS+aMwixFFO 4qmpISNOTFPpU7Bk8jU1qbnhpT8DsbjI5KG72tGneea3C3bDMPZm9QjxU0xSAUHLDdEC YcUaAZVR3XrglhNIKlAa2OCmXCJWP8Wgrmne+V00H0mfEbPQtW9CUODvoW+d9XPxQDgi kWWFxN1S3Rpy6WSaokzqtDhRNZG8El35hnTzuuPjldJswQDDT7B5/TfPSRee46meXt2o RDbg== X-Gm-Message-State: AA+aEWakL4bfWJhjXx8z5Vc7idUlRRSrqO5XQ58+nOYLUgPM5Sziq0zC BmV9rOBoPnjxOz8oXAf0TP3kyJrUSan0LlvbjhO7L74U X-Google-Smtp-Source: AFSGD/Xal6eAyxfdultCBQyiKD/L9nSoEjAuB8dz503QIpYIVE51N/N9B8HEvN69+BoiOPWJdJIY7ejmFecMqfvUKO8= X-Received: by 2002:a17:906:f6cb:: with SMTP id jo11-v6mr46873924ejb.80.1546868372091; Mon, 07 Jan 2019 05:39:32 -0800 (PST) MIME-Version: 1.0 References: <1546771383530.99285@kuleuven.be> <1546771678305.41844@kuleuven.be> <1546868053120.21793@kuleuven.be> In-Reply-To: <1546868053120.21793@kuleuven.be> From: Andy Talbot Date: Mon, 7 Jan 2019 13:39:17 +0000 Message-ID: To: rsgb-lf-group@groups.io Cc: "rsgb_lf_group@blacksheep.org" 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 @@CONTACT_ADDRESS@@ for details. Content preview: OOPS I forgot that! Careless! Was using the period for JT9-1 In which case my speculation about soft the decision decoder must be applicable, at least to some extent. To work with a drift of several tone-spacings; quite impressive. Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [2a00:1450:4864:20:0:0:0:535 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (andy.g4jnt[at]gmail.com) 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 HTML_FONT_LOW_CONTRAST BODY: HTML font color similar or identical to background 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: a9f27894b14321629f793c65c0512237 Subject: LF: Re: [rsgb-lf-group] FW: JT9-5 Drift Content-Type: multipart/alternative; boundary="000000000000d5375d057ede5be4" 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=HTML_30_40,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY 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 --000000000000d5375d057ede5be4 Content-Type: text/plain; charset="UTF-8" OOPS I forgot that! Careless! Was using the period for JT9-1 In which case my speculation about soft the decision decoder must be applicable, at least to some extent. To work with a drift of several tone-spacings; quite impressive. Andy www.g4jnt.com On Mon, 7 Jan 2019 at 13:34, Rik Strobbe wrote: > Hello Andy, > > > the drift is given as Hz/min, so for JT9-5 the drift can be as high as 1Hz > over the (almost) 5 minute TX cycle. > > The decoder must somehow be able to correct the drift within certain > limits. > > > 73, Rik ON7YD - OR7T > > > > ------------------------------ > *Van:* rsgb-lf-group@groups.io namens Andy > TALBOT > *Verzonden:* maandag 7 januari 2019 14:13 > *Aan:* rsgb-lf-group@groups.io > *CC:* rsgb_lf_group@blacksheep.org > *Onderwerp:* Re: [rsgb-lf-group] FW: JT9-5 Drift > > The JT9-5 tone spacing is 0.29Hz, so those drift figures correspond > roughly to a bit less than one complete tone spacing in the transmission > period. Which makes intuitive sense. The error correction allows it to > "lose" the few symbols at the end where it has drifted too far, while those > at the start are near enough to work normally. > > (Pure speculation) The soft decision process in the decoder algorithm will > base its metric on how far the received signal is away from where it ought > to be, so a tone that has drifted into an adjacent bin may still have a > quite strong weighting applied. > > BTW Rik, you still appear to be copying these posts to the now-dead Yahoo > Group > > Andy > www.g4jnt.com > > > > On Sun, 6 Jan 2019 at 10:48, Rik Strobbe wrote: > >> Dear all, >> >> >> Roger, VK4YB, asked me about JT9-5 frequency stability requirement. >> >> As this might be interesting for others too, my answer below. >> >> >> 73 & HNY >> >> >> Rik ON7YD - OR7T >> >> >> ------------------------------ >> *Van:* Rik Strobbe >> *Verzonden:* zondag 6 januari 2019 11:43 >> *Aan:* Roger Crofts >> *Onderwerp:* Re: JT9-5 Drift >> >> >> Hello Roger, >> >> >> as JT9-2 and JT9-5 signals are resampled to JT9-1 to be decoded by WSJT >> decoder engine it all depends on the drift tolerance of that decoder. >> >> For JT9-2 the frequency stability must be 2.222 times better than for >> JT9-1. >> >> For JT9-5 it must even be 5.926 be better. >> >> As I couldn't find any information about the required JT9-1 stability I >> did some brief tests with JT9-5: >> >> - At -5 dB level a drift up to 0.35 Hz/min seems acceptable. >> >> - At -15 dB level it is 0.26 Hz/min. >> >> - At -25 dB level it is 0.24 Hz/min >> >> - At -30 dB level it is 0.22 Hz/min >> >> - At -34 dB level (more or less the JT95 limit) it is 0.20 Hz/min >> >> But as said this was just a brief test, these numbers should be handled >> with some caution. >> >> Also keep in mind that this numbers represent the combined TX and RX >> drift (according to Murphy TX and RX drift will always be opposite). >> >> If using a transverter the TX drift is the combined drift of the driver >> TX and the transverter. >> >> Furthermore I assumed that the drift was linear over time, for frequency >> jumps it might be different. >> >> Another frequency instability source will be the ionosphere, but there is >> little we can do about that (but the more stable TX and RX the more room >> for ionospheric instabilities). >> >> Based on the above I would suggest to aim for a LO stability of no worse >> than 0.1 Hz/min, 0.05 Hz/min would be even better for weak signal DX (and >> that is what JT9-5 is all about). >> >> >> Tests over the past weeks have shown that JT9-5 works very well for >> 136 kHz DX (N1BUG was copied by numberous EU stations). >> >> On 472 kHz K3MF has been reported in Europe (as far as I know by G0LUJ >> and myself). >> >> >> 73, Rik ON7YD - OR7T >> >> > > Virus-free. > www.avg.com > > <#m_-5574909818073301296_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > _._,_._,_ > ------------------------------ > Groups.io Links: > > You receive all messages sent to this group. > > View/Reply Online (#8446) > | Reply To Group > > | Reply To Sender > > | Mute This Topic | New Topic > > > Your Subscription | Contact > Group Owner | Unsubscribe > [ > andy.g4jnt@gmail.com] > _._,_._,_ > > --000000000000d5375d057ede5be4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
OOPS
I forgot th= at!=C2=A0 =C2=A0Careless!
Was using the period for JT9-1

In which case my speculation about soft the= decision decoder must be applicable, at least to some extent.
To work with a drift of several tone-spacings; quite impressive.


On Mon, 7 Jan 2019 at 13:34, Rik Strobbe <rik.strobbe@kuleuven.be> wrote:<= br>

Hello Andy,


the drift is given as Hz/min, so for JT9-5 the drift can be as high as 1= Hz over the (almost) 5 minute TX cycle.

The decoder must=C2=A0somehow be able to correct the drift within certai= n limits.


73, Rik=C2=A0 ON7YD - OR7T



Van= : rsgb-lf-= group@groups.io <rsgb-lf-group@groups.io> namens Andy TALBOT <andy.g4jnt@gmail.com= >
Verzonden: maandag 7 januari 2019 14:13
Aan: rs= gb-lf-group@groups.io
CC: rsgb_lf_group@blacksheep.org
Onderwerp: Re: [rsgb-lf-group] FW: JT9-5 Drift
=C2=A0
The JT9-5 tone spacing is 0.29Hz, so those drift figures correspond roughly= to a bit less than one complete tone spacing in the transmission period.= =C2=A0 Which makes intuitive sense.=C2=A0 The error correction allows it to= "lose" the few symbols at the end where it has drifted too far, while those at the start are near enough to work norm= ally.

(Pure speculation) The soft decision process in the decoder algorithm will = base its metric on how far the received signal is away from where it ought = to be, so a tone=C2=A0 that has drifted into an adjacent bin may still have= a quite strong weighting applied.=C2=A0

BTW Rik, you still appear to be copying these posts to the now-dead Yahoo G= roup

Andy


On Sun, 6 Jan 2019 at 10:48, Rik Strobbe <rik.strobbe@kuleuven.be= > wrote:

Dear all,


Roger, VK4YB, asked me about JT9-5 frequency stability requirement.

As this might be interesting for others too, my answer below.


73 & HNY


Rik=C2=A0 ON7YD - OR7T


Van: Rik Strobbe
Verzonden: zondag 6 januari 2019 11:43
Aan: Roger Crofts
Onderwerp: Re: JT9-5 Drift
=C2=A0

Hello Roger,


as JT9-2 and JT9-5 signals are resampled to JT9-1 to be decoded by WSJT = decoder=C2=A0engine it all depends on the drift tolerance of that decoder.<= br>

For JT9-2 the frequency stability must be 2.222 times better than for JT= 9-1.

For JT9-5 it must even be 5.926 be better.

As I couldn't find any information about the required=C2=A0JT9-1 sta= bility I did some brief=C2=A0tests with JT9-5:

- At -5=C2=A0dB level a drift up to 0.35=C2=A0Hz/min seems=C2=A0acceptab= le.

- At -15=C2=A0dB level it is 0.26 Hz/min.

- At -25 dB level it is 0.24=C2=A0Hz/min

- At -30=C2=A0dB level it is 0.22 Hz/min

- At -34 dB level (more or less the JT95 limit) it is 0.20 Hz/min

But as said this was just a brief test, these numbers should be handled = with some caution.

Also keep in mind that this numbers represent the combined TX and RX dri= ft (according to Murphy TX and RX drift=C2=A0will always be opposite).

If using a transverter the TX drift is the combined drift of the driver = TX and the transverter.

Furthermore I assumed that the drift was linear over time, for frequency= jumps it might be different.

Another frequency instability source will be the ionosphere, but there i= s little we can do about that (but the more stable TX and RX the more room = for ionospheric instabilities).

Based on the above I would suggest to aim for a LO stability of no worse= than 0.1 Hz/min, 0.05 Hz/min would be even better for weak signal DX (and = that is what JT9-5 is all about).


Tests over the past weeks have shown that JT9-5 works very well for 136= =C2=A0kHz DX (N1BUG was copied by numberous EU stations).

On 472 kHz K3MF has=C2=A0been reported in Europe (as far as I know by G0= LUJ and myself).


73, Rik=C2=A0 ON7YD - OR7T


3D"" Virus-free. www.avg.com
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View/Reply Online (#8446) | Reply To Group =20 | Repl= y To Sender =20 | =20 Mute= This Topic =20 | New = Topic

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