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 x07DOr16006935 for ; Mon, 7 Jan 2019 14:24:59 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ggUjb-0000Sw-OW for rs_out_1@blacksheep.org; Mon, 07 Jan 2019 13:14:27 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ggUjH-0000Sf-Uc for rsgb_lf_group@blacksheep.org; Mon, 07 Jan 2019 13:14:07 +0000 Received: from mail-ed1-x52f.google.com ([2a00:1450:4864:20::52f]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1ggUjD-0002Ya-US for rsgb_lf_group@blacksheep.org; Mon, 07 Jan 2019 13:14:06 +0000 Received: by mail-ed1-x52f.google.com with SMTP id f9so799199eds.10 for ; Mon, 07 Jan 2019 05:14:02 -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=VwmIsTnDJmSh9iFEt/P8RftQixv1yLeAYWGmUcvZsuk=; b=bCqSQ1D+XxTt49ywWZn3gfok77mc0KBKDOCIISysVgV9TVb75+23/yB74vSMXuZUW9 e4FmsmseTpgXhUc5uu4/g0zZW2UZ/K1eGJ9zEFvEEUYTbuaZk4tNqO892J5bRDruBiby GBie51aSxqF+YttYXdtJkyYMdbORxE7RO+wx1MtKkFT4kaBqR/0EaG8ksRascIFmC9St EF9VvR3icAmPMQ75PX84ObmmOZNaB0fo4N52VCVCBUWDFwHBnzH4ugtwZMquZuqHx1Fx y33hxLMr230E/pLqbwl96Hv04sFAdWx6RFo4fUAUH14I3cl3WiiJ4onsLUnURfNIomY5 e83g== 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=VwmIsTnDJmSh9iFEt/P8RftQixv1yLeAYWGmUcvZsuk=; b=P711kK7R+4VyGzg5khg+mwnrPFDUkRsmZ7p8bUGfl7wPp2M7rRgLEtyxyqgJbahbu/ 74SqEGEVBjMhDquNKeqPMITbBQICV5m3Jp46hcpSncz/pccRJC9PM5qUw8aqQUO99N4/ 4spR6WIHNylLvYLd1JrTlLjWTuuU78WQ+SrdqNmjkC6aEwyyFYVi7rxW7Tu204HJRl5c NmPvIEBK94frZHbQyO7TzUZLEbQSPbgoieg2MVkIgDcUdAM/PBhEh2epENpDzcFqCljF epxLioWdC4fZDPgf6ROCL4su0vEFuzsLUDvnqzmkFzVsT7jGd/gH9H8PjQJBB2WM2ZRg RiyA== X-Gm-Message-State: AA+aEWZ5Upy1VUVdqDn12EibNjkh5ejeCHIdcj418BM1xx3FOgqEwd/w xjWB4kkfYcwI6G+ZTAmDZF38sJlwg2DZ5nKEGvE= X-Google-Smtp-Source: AFSGD/UTMLNxKmalNeEV0YdeTmO2Ik/TbOvZvXdPcGuWaHq09lgfI1MRevioZBlf5z/Zqk5/YsdeONGQW3Sq+sWJ080= X-Received: by 2002:a17:906:f6cb:: with SMTP id jo11-v6mr46810817ejb.80.1546866841892; Mon, 07 Jan 2019 05:14:01 -0800 (PST) MIME-Version: 1.0 References: <1546771383530.99285@kuleuven.be> <1546771678305.41844@kuleuven.be> In-Reply-To: <1546771678305.41844@kuleuven.be> From: Andy Talbot Date: Mon, 7 Jan 2019 13:13:46 +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: 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 a [...] 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 [2a00:1450:4864:20:0:0:0:52f 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: 44f86b71899a78e1998f84722b8e93d8 Subject: LF: Re: [rsgb-lf-group] FW: JT9-5 Drift Content-Type: multipart/alternative; boundary="000000000000a03b17057ede00bd" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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 --000000000000a03b17057ede00bd Content-Type: text/plain; charset="UTF-8" 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 > _._,_._,_ > ------------------------------ > Groups.io Links: > > You receive all messages sent to this group. > > View/Reply Online (#8441) > | Reply To Group > > | Reply To Sender > > | Mute This Topic | New Topic > > > Your Subscription | Contact > Group Owner | Unsubscribe > [ > andy.g4jnt@gmail.com] > _._,_._,_ > > Virus-free. www.avg.com <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> --000000000000a03b17057ede00bd Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
The JT9-5 tone spacing is 0.29H= z, so those drift figures correspond roughly to a bit less than one complet= e tone spacing in the transmission period.=C2=A0 Which makes intuitive sens= e.=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 normally.

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

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

Andy
<= div dir=3D"ltr" class=3D"gmail_signature" data-smartmail=3D"gmail_signature= ">


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

_._,_._,_
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