Return-Path: X-Spam-DCC: paranoid 1170; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, NO_REAL_NAME autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tABNfniT020191 for ; Thu, 12 Nov 2015 00:41:49 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Zwex3-0000Mi-If for rs_out_1@blacksheep.org; Wed, 11 Nov 2015 23:37:17 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Zwex3-0000MZ-68 for rsgb_lf_group@blacksheep.org; Wed, 11 Nov 2015 23:37:17 +0000 Received: from nina.ucs.mun.ca ([134.153.232.76]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.86) (envelope-from ) id 1Zwew1-0002jJ-KL for rsgb_lf_group@blacksheep.org; Wed, 11 Nov 2015 23:37:16 +0000 Received: from plato.ucs.mun.ca (plato.ucs.mun.ca [134.153.232.153]) by nina.ucs.mun.ca (8.13.1/8.13.1) with ESMTP id tABNZsGt016873 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 11 Nov 2015 20:05:54 -0330 Date: Wed, 11 Nov 2015 20:05:54 -0330 (NST) From: jcraig@mun.ca X-X-Sender: jcraig@plato.ucs.mun.ca To: rsgb_lf_group@blacksheep.org In-Reply-To: <8D2EABAF0379B74-9084-3D874@webmail-vd017.sysops.aol.com> Message-ID: References: <8D2EABAF0379B74-9084-3D874@webmail-vd017.sysops.aol.com> MIME-Version: 1.0 Content-ID: X-Scan-Signature: ecf102e6d15c1e466f357d5e6d956ac3 Subject: Re: LF: VO1NA frequency Content-Type: MULTIPART/MIXED; BOUNDARY="-1719232024-2088675306-1447272887=:6519" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 4981 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---1719232024-2088675306-1447272887=:6519 Content-Type: TEXT/PLAIN; CHARSET=X-UNKNOWN; FORMAT=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Content-ID: Hi Markus (and thank-you to Chris, Urlich, Iban and Graham for=20 reports/relays) Your critiques of my signals are very thorough and masterful. I am most grateful. There is a concensus amongst you, Domenico and Stefan that I've gone off frequency again, at times more than 1 mHz! Hopefully this will be corrected soon. I'll post your nice plots on the web if you don't mind. In the mean time, I ran Paul's ebbaut.c on the MUN unix box and an old Model B raspi. It compiled flawlessly. I had to put in arguments for -S and -r which I chose at random, my callsign and pussycat's name and was rewarded with a long list of 0's and 1's. So if I send a long carrier with a phase inversion every time a 1 is encountered, it will be a valid ebnaut transmission? What is the duration of the elements and what arguments should I pass to ebnaut.c? Also, would a transformer + DPDT relay work? A ring mixer might not take kindly to a 12V squarewave. Please excuse my naivety! Also, XYL is wondering why you want the other details of the cat. She was my ground crew today while I was atop the tower so I must be diplomatic! MNI TNX Joe VO1NA On Wed, 11 Nov 2015, Markus Vester wrote: > Joe, > =C2=A0 > more of the same from last night, this time with=C2=A0frequency and level= plots. Again we see some frequency variation of similar size as yesterday.= It is not clear how much of that is due to propagation,=C2=A0I only think = that the=C2=A0rise=C2=A0near the end is due to Doppler=C2=A0from the=C2=A0d= escent of the ionosphere at sunrise.=C2=A0Russian=C2=A0Loran lines on 13747= 5 and 137482.5 seemed to have less overnight variation (~ 0.1 mHz), but the= n of course the intra-European path from Slonim is very different from your= s.=C2=A0 > =C2=A0 > Regarding EbNaut carrier analysis:=C2=A0for some reason (lack of coffee?)= , I only saw Domenico's earlier mail after I had=C2=A0sent mine, so please = excuse me for basically having described=C2=A0the same procedure again.=C2= =A0Anyway it's good that we=C2=A0both=C2=A0arrived at the same conclusion:= =C2=A0If Joe started sending=C2=A0EbNaut PSK with his=C2=A0oscillator as=C2= =A0it is now, we would very likely be able to decode it here.=C2=A0 > =C2=A0 > Joe so all you need now is a diode ring-mixer for PSK modulation and Paul= 's ebnaut-tx program.=C2=A0Symbol=C2=A0timing=C2=A0will=C2=A0be derived fro= m=C2=A0the PC clock,=C2=A0so with NTP=C2=A0available there's no need to inv= olve GPS at all. If Paul brought his LF receiver back to life, he could pro= bably copy you even=C2=A0if you reduced=C2=A0TX power to 0.1 Deccas. > =C2=A0 > How many cats do you have? We want to know=C2=A0names, colours, sex and a= ge for all of them ;-) > =C2=A0 > All the best, > Markus (DF6NM) > =C2=A0 > =C2=A0 > PS. SpecLab question: Wolf is there a way to extract peak frequencies fro= m past spectrogram lines (semi-)automatically, without having to manually= =C2=A0move=C2=A0and read the mouse cursor over each point, e.g. something l= ike a peak_f(f1,f2, time) interpreter function? > > =C2=A0 > -----Urspr=C3=BCngliche Mitteilung----- > Von: Markus Vester <markusvester@aol.com> > An: rsgb_lf_group <rsgb_lf_group@blacksheep.org> > Verschickt: Mi, 11 Nov 2015 1:24 am > Betreff: LF: VO1NA frequency > =C2=A0 Hi Joe, > =C2=A0 > the attached plot shows the frequency=C2=A0stability of=C2=A0your=C2=A0o= pds trace received last night=C2=A0http://df6nm.bplaced.net/LF/opds32_1511= 10_0736.png=C2=A0. Each data point is the interpolated peak of a single 4= 38 uHz FFT (i.e. 38 minute window). The average frequency seems to be 0.7 = mHz below=C2=A0nominal, and there are small temporal variations=C2=A0up to= =C2=A00.5 mHz in either direction.=C2=A0Though some of that=C2=A0is probab= ly=C2=A0attributable=C2=A0to noise and propagation, I believe that there i= s also a bit of inherent instability in=C2=A0the frequency source.=C2=A0Ac= tually a few parts per billion=C2=A0is quite good for a free running=C2=A0= OCXO (assuming the "D" stands for "double oven" and not "discipled"), and = that the calibration was done over a 10 MHz=C2=A0HF link. > =C2=A0 > Is this good enough for EbNaut? During the experiments with IZ7SLZ we fo= und that for full sensitivity the phase variation over the EbNaut=C2=A0seq= uence duration should not be much more than 90=C2=B0. Thus for a half-hour= message the frequency should be ideally constant and known to about 0.14 = mHz. If there is more variation=C2=A0we=C2=A0often=C2=A0can still get=C2= =A0decodes, but we will have to find the best frequency offset by trial an= d error, which can be cumbersome if the signal is weak. > =C2=A0 > I also fed opds data files from your Sat/Sun transmissions to the EbNaut= =C2=A0decoder. The idea was to see if=C2=A0your Opera transmissions would = actually produce=C2=A0the all-asterisk=C2=A0decode which is expected for a= non-PSK-keyed straight carrier, and to observe the symbol phase evolution= over the 38 minute duration.=C2=A0Starting midnight UT, one decode was att= empted every 30 minutes, using a setting for 464 raw symbols (4 characters= )=C2=A0and 5 seconds per symbol. A=C2=A0frequency offset of -0.6 mHz was= =C2=A0selected=C2=A0to obtain flat phase during the first decodes, and=C2= =A0that offset=C2=A0was=C2=A0kept for all later attempts. Despite the Oper= a gaps which=C2=A0degrade or drop half of the available symbols,=C2=A012 o= ut of 13 decode attempts=C2=A0produced the correct=C2=A0"****" message,= =C2=A0e.g. http://df6nm.bplaced.net/LF/r0317.png . However at times the fr= equency drift was quite visible=C2=A0on the=C2=A0phase plot,=C2=A0e.g. in = http://df6nm.bplaced.net/LF/s0317.png=C2=A0(flat phase around 3:17) versus= http://df6nm.bplaced.net/LF/s0347.png=C2=A0(upward phase slope around 3:4= 7).=C2=A0 > =C2=A0 > Scaling down to VLF, deviations from the same oscillator will be 16x sma= ller (~30 uHz at 8.3 kHz). This will be probably good enough even for=C2= =A0narrow FFT bins, corresponding to several hours coherent carrier integr= ation or slow EbNaut decodes. > =C2=A0 > All the best, > Markus (DF6NM) > > > From: jcraig@mun.ca > Sent: Saturday, November 07, 2015 3:45 PM > To: rsgb_lf_group@blacksheep.org > Subject: Re: LF: VO1NA opds-32 > > > > > LF Group, > > Again, thanks to SV8RV DF2JP PA7EY and DF6NM for the reports. > > In my last post I reported the drift was constrained to within 1 Hz. > This should be 1 mHz.=C2=A0 Thanks Markus for your assurances that this > should be adequate for EbNaut which I hope to use to send send our > cat's name on LF.=C2=A0 The little curls appear often on the QRSS traces = on > your high res spectra.=C2=A0 Doppler variations were removed from the 10 = MHz > WWV signals with harmonic regression when the DOCXO was calibrated > so this effect is seen on LF but not as strongly. > > After=C2=A0 reading about EbNaut on Paul Nicholson's pages it seems I ha= ve > much catching up ahead.=C2=A0 Fasinating stuff! > > Can the EbNaut phase inversions be done without an absolute time > reference?=C2=A0 I'm cheap and lazy so hoping GPS will not be needed. > > The Opera will be doing an encore tonight and if the wind stays low > a tower climbing expedition is planned for the afternoon. > > 73 > Joe VO1NA > > > On Sat, 7 Nov 2015, Markus Vester wrote: > > > Hi Joe, LF, > > > > during the last couple of nights, opds detected all of your transmi= ssions between about 22=C2=A0 and 7:30 UT. > > > > Attached is a zoomed 40 mHz section from my opds-32 spectrogram, sh= owing your central coherent carrier which contains half of the transmitted= average power. It seems to be about 0.5 mHz below 137477 Hz (possibly due= to a calibration error in my receiver). The 2.7 mHz spaced sidelines duri= ng the early part (bottom) were caused by 6-minute-periodic interruptions = from my own MF WSPR transmissions. However the little curls near the carri= er can presumably be attributed to Doppler-shifted multipath components. T= he carrier was still weakly visible for another hour after the last detect= ion. > > > > Comparing the looks of the carrier to earlier IZ7SLZ transmissions,= the stability of the signal and the path seems quite sufficient for half-= hour EbNaut PSK transmissions. Unfortunately I missed the opportunity to s= ave the raw data and analyze phase evolution using the EbNaut decoder itsel= f - will try that next time. > > > > All the best, > > Markus (DF6NM) > > > > > > > > > > From: jcraig@mun.ca > > Sent: Saturday, November 07, 2015 12:03 AM > > To: rsgb_lf_group@blacksheep.org > > Subject: Re: LF: last night opera opds detection in km07ks > > > > > > LF Group, > > > > > > I am grateful to Joe DF2JP for his captures QRSS and Opera > > Dionysious SV8RV for his OP decodes to Domenico IZ7SLZ > > for his OPDS decodes, and thanks to DF6NM for opds! > > > > I do not know if my DOCXO is stable enough for EbNaut. > > It was set a couple of years ago and has not drifted more than > > 1 Hz since then.=C2=A0 It seems the phase decoherence has stopped > > haunting me. > > > > I am hoping to replace the halyard for the other 100m wire soon. > > > > OP32 again tonight as send this email. > > > > 73 > > Joe > > > > > > > ---1719232024-2088675306-1447272887=:6519--