Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-ma01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1618F38000082; Sun, 22 Apr 2012 05:22:45 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SLsyl-0007cg-1e for rs_out_1@blacksheep.org; Sun, 22 Apr 2012 10:21:11 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SLsyk-0007cX-6N for rsgb_lf_group@blacksheep.org; Sun, 22 Apr 2012 10:21:10 +0100 Received: from mk-filter-3-a-1.mail.tiscali.co.uk ([212.74.100.54] helo=mk-filter-3-a-1.mail.uk.tiscali.com) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1SLsyf-0000oF-RJ for rsgb_lf_group@blacksheep.org; Sun, 22 Apr 2012 10:21:09 +0100 X-Trace: 750006160/mk-filter-3.mail.uk.tiscali.com/B2C/$b2c-THROTTLED-DYNAMIC/b2c-CUSTOMER-DYNAMIC-IP/88.104.47.191/None/g4wgt@tiscali.co.uk X-SBRS: None X-RemoteIP: 88.104.47.191 X-IP-MAIL-FROM: g4wgt@tiscali.co.uk X-SMTP-AUTH: X-Originating-Country: GB/UNITED KINGDOM X-MUA: Microsoft Windows Mail 6.0.6002.18197Produced By Microsoft MimeOLE V6.1.7601.17609 X-IP-BHB: Once X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AngHACjNk09YaC+//2dsb2JhbABEmm+SVIN8gQiCCQEBBQhBDQIPHQEEBQMDEQQBAQoMGTMGFggGEwgJCYd5B6lXgi6NUYpygxCCTmMElwuEUIpdgmqBUwg X-IronPort-AV: E=Sophos;i="4.75,462,1330905600"; d="scan'208,217";a="750006160" Received: from 88-104-47-191.dynamic.dsl.as9105.com (HELO GaryPC) ([88.104.47.191]) by smtp.tiscali.co.uk with SMTP; 22 Apr 2012 10:21:01 +0100 Message-ID: From: "Gary G4WGT" To: References: <4F935E6B.2020203@iup.uni-heidelberg.de> In-Reply-To: <4F935E6B.2020203@iup.uni-heidelberg.de> Date: Sun, 22 Apr 2012 10:21:01 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18197 X-MIMEOLE: Produced By Microsoft MimeOLE V6.1.7601.17609 X-Spam-Score: -0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Stefan, LF, Nice job there, well done. Martin's situation makes us realise how fortunate we are in UK, US & Eu etc. [...] 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 [212.74.100.54 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (g4wgt[at]tiscali.co.uk) -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 29168ad3cbe6e84866aad11301f49cdd Subject: LF: Re: 137 kHz in South America ! Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01CD2071.9E1B3970" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=HTML_MESSAGE, MISSING_OUTLOOK_NAME 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-SCOLL-SCORE: 0:2:464878880:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d60094f93cde56ad9 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_000B_01CD2071.9E1B3970 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable Hi Stefan, LF, Nice job there, well done. Martin's situation makes us realise how fortunate we are in UK, US & Eu = etc. 73, Gary - G4WGT. ----- Original Message -----=20 From: Stefan Sch=E4fer=20 To: rsgb_lf_group@blacksheep.org=20 Cc: David - VK2DDI=20 Sent: Sunday, April 22, 2012 2:27 AM Subject: LF: 137 kHz in South America ! LF! I'm glad to tell you about a most interesting and pleasant story and = good news for the LF DX interested OMs, especially in the U.S., the UK = and EU. Some weeks ago the VK guys and me decided that the EU-VK 137 kHz = spring season is over now. The DCF39 S/N became lower and lower and QSB = rised. An overview of my worked DX (one-way) showed that i have EU, AS, = AF, NA and OC but SA, the South American continent is missed.=20 Compared to the VK path, where a significant part goes above land, = even desert, SA should be much easier, at least the northern part. From the recent history i know that it is possible for all of us to = motivate and recruit radio amateurs to the LF and VLF band, even if they = didn't even know that an amateur allocation arround 137 kHz exists for = many countries. I can tell you it is an exciting work to tell others = about the LF hobby and we could do much more to make the band more = alive. Well, so my idea was to find someone in SA to arrange a LF system (at = least for receive) and a grabber page that makes it available to all. = First i wanted to concentrate on the northern part of the continent.=20 That's how it goes: :-) A very suitable website to find potential LF newcomers is = http://pskreporter.info/pskmap.html. You can simply zoom the country = where you like to have a new station and see if you can find a callsign = :-) You can be sure that everyone who apperas on this website is an = active amateur radio station that has a RX, antenna, PC and internet = connection. Most often they have an account at www.qrz.com too. Here you = will find their email adress. It doesn't matter if they are still concentrated to HF and digimodes. = You know, LF is a very interesting part of amateur radio work and if you = can fascinate them, it is a small step! Quickly i actually found a station in Venezuela, Martin/YV7MAE. He is = in the very north east, in FK81BD. He has never done anything on 137 kHz = but is very interested... The receive setup is a IC706 and a IC703. The = 703 is used for LF now. In that country it is not so easy just to build = a PA0RDT antenna or a resonated loop since the electronic parts are = simply not available. Parts are rare and expensive. Even ordering parts = from ebay or so isn't easy since it's not so easy to change the money in = USD or EUR. So we had to improvise and were limited to some few antenna = systems. There is not even a chance for him to get an oscilloscope or a = signal generator. So we tried to get out a signal from the 703 or 706 = but nothing seems to come out.. It would be possible to down divide a = signal at 1.8 MHz to the LF band, using a CD4060 or so. But it is not = available!!... So, we decided to use a normal wire antenna and took an old ferrite = transformer from an old damaged PC supply. A isolating transformer was = wound with 60 turns on the antenna side, grounded at the lower end with = an exclusive LF earth. The RX winding has 20 turns and is connected by a = short 75 Ohm coax cable to the RX (all improvised). Martin still plays = arround to find the best ratio and number of turns for an optimal S/N, = i.e. matching, because the magnetic parameters of the transformer are = unknown. BTW the wire is a 38m long iron wire (improvised :-) ) at about = 7m above ground. First nothing at all was received. There was a misunderstanding how to = connect the antenna to the transformer but later it was all fine. In the = web i found a NDB which is very close to his QTH: = http://www.ourairports.com/navaids/MTA/Margarita_NDB_VE/ After spending some disappointing receive nights, now Martin actually = received another NDB, TAB at 323 kHz! This was his first received signal = with this receive setup, yesterday! Now he acutually has a reference = signal which comes from the far field. Quickly he found that 60 turns = primary were better than 40 and that 80 turns resulted in the same = signal strength than 60.... So far so good... We tried then to receive the carrier of the 153 khz AM broadcast = staions, which worked very well in the first attempt. Slowly it became = dark in YV and so we actually successfully received traces of DCF39!!! = :-) The mile stone! After preparing the grabber page i prepared a = SpecLab file to display DCF39 in 45 mHz over the night. The images were = uploaded to the webpage and saved to a local folder. Now looking to the = archive, best S/N was arround 20 dB (so far without any noise = reduction!), seen here on Martin's dropbox: = http://dl.dropbox.com/u/74746618/Pictures%20for%20exchange/DCF39_09.jpg This is a very clear trace but still it looks like lack of = sensitivity, so we have to improve the system further. Also the typical = QRN morning dip is not visible! But anyway a very good result after some = days. It shows that the frequency drift and offset of the 703 is = reasonable, also suitable for QRSS-60 detections later. We also checked = in a wideband window, covering 0...3 kHz, i.e. the SSB filter width, = that there seems to be no drifting mains harminics or SMPS sidebands, = hopefully not due to lack of sensitivity ;-) Probably we need an air coil and a well resonated receive system to = generate a higher signal level for the deaf IC703. He also has some = variable capacitors that look like arround 200 pF or so. So it should be = possible to match the system if it has some Q. This first success with = the SMPS transformer was very important though! Also the absence of = strong QRM makes the project even more promising now. Luckily Martin has a internet flatrate, so we worked together on his = PC using a Teamviewer remote connection to install a dropbox, a grabber = page and SpecLab, with automatic jpg upload. It was quite difficult for = me since the PC is in Spanish :-) Who knows, maybe some day he will appear here in the LF reflector. He = is also in a nice local radio club where they have a high tower for a = VHF repeater. Maybe they will add a transmit antenna soon? ;-) Does = someone know about a LF allocation in Venezuela? Not only for US, UK, and EU but of course for the southern stations in = South america this could be an interesting new challenge. Soon we will = make first tests in the 137 kHz band but it looks like we have to find = another 10 dB S/N from somewhere. Any good ideas? No, a preamp cannot be = built, due to lack of electronic parts! Somehow i find that all very = exciting, i mean not having all the parts available but have to = improvise, maybe like in the very early days! :-) So let's hope for continued progress, improvements and interest! Ah, of course, the link tho the new Venezuela LF Grabber (still in = test mode): http://dl.dropbox.com/u/74746618/LF/YV7MAE_LF_Grabber.html It becomes more interesting at night of course. Local time is UTC-4. = So far a test window of DCF39 is shown but soon we will run a EU60 = and/or TA60 window. 73, Stefan/DK7FC ------=_NextPart_000_000B_01CD2071.9E1B3970 Content-Type: text/html; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable
Hi Stefan, LF,
 
Nice job there, well done.
 
Martin's situation makes us realise how = fortunate we are=20 in UK, US & Eu etc.
 
73, Gary - G4WGT.
 
----- Original Message -----
From:=20 Stefan = Sch=E4fer
Sent: Sunday, April 22, 2012 = 2:27=20 AM
Subject: LF: 137 kHz in South = America=20 !

LF!

I'm glad to tell you about a most = interesting and=20 pleasant story and good news for the LF DX interested OMs, especially = in the=20 U.S., the UK and EU.

Some weeks ago the VK guys and me decided = that the=20 EU-VK 137 kHz spring season is over now. The DCF39 S/N became lower = and lower=20 and QSB rised. An overview of my worked DX (one-way) showed that i = have EU,=20 AS, AF, NA and OC but SA, the South American continent is missed. =
Compared=20 to the VK path, where a significant part goes above land, even desert, = SA=20 should be much easier, at least the northern part.

From the = recent=20 history i know that it is possible for all of us to motivate = and=20 recruit radio amateurs to the LF and VLF band, even if they didn't = even know=20 that an amateur allocation arround 137 kHz exists for many countries. = I can=20 tell you it is an exciting work to tell others about the LF hobby and = we could=20 do much more to make the band more alive.
Well, so my idea was to = find=20 someone in SA to arrange a LF system (at least for receive) and a = grabber page=20 that makes it available to all. First i wanted to concentrate on the = northern=20 part of the continent.

That's how it goes: :-)
A very = suitable=20 website to find potential LF newcomers is http://pskreporter.info/pskm= ap.html.=20 You can simply zoom the country where you like to have a new station = and see=20 if you can find a callsign :-) You can be sure that everyone who = apperas on=20 this website is an active amateur radio station that has a RX, = antenna, PC and=20 internet connection. Most often they have an account at www.qrz.com too.=20 Here you will find their email adress.
It doesn't matter if they = are still=20 concentrated to HF and digimodes. You know, LF is a very interesting = part of=20 amateur radio work and if you can fascinate them, it is a small=20 step!

Quickly i actually found a station in Venezuela, = Martin/YV7MAE.=20 He is in the very north east, in FK81BD. He has never done anything on = 137 kHz=20 but is very interested... The receive setup is a IC706 and a IC703. = The 703 is=20 used for LF now. In that country it is not so easy just to build a = PA0RDT=20 antenna or a resonated loop since the electronic parts are simply not=20 available. Parts are rare and expensive. Even ordering parts from ebay = or so=20 isn't easy since it's not so easy to change the money in USD or EUR. = So we had=20 to improvise and were limited to some few antenna systems. There is = not even a=20 chance for him to get an oscilloscope or a signal generator. So we = tried to=20 get out a signal from the 703 or 706 but nothing seems to come out.. = It would=20 be possible to down divide a signal at 1.8 MHz to the LF band, using a = CD4060=20 or so. But it is not available!!...
So, we decided to use a normal = wire=20 antenna and took an old ferrite transformer from an old damaged PC = supply. A=20 isolating transformer was wound with 60 turns on the antenna side, = grounded at=20 the lower end with an exclusive LF earth. The RX winding has 20 turns = and is=20 connected by a short 75 Ohm coax cable to the RX (all improvised). = Martin=20 still plays arround to find the best ratio and number of turns for an = optimal=20 S/N, i.e. matching, because the magnetic parameters of the transformer = are=20 unknown. BTW the wire is a 38m long iron wire (improvised :-) ) at = about 7m=20 above ground.

First nothing at all was received. There was a=20 misunderstanding how to connect the antenna to the transformer but = later it=20 was all fine. In the web i found a NDB which is very close to his QTH: = http://= www.ourairports.com/navaids/MTA/Margarita_NDB_VE/
After=20 spending some disappointing receive nights, now Martin actually = received=20 another NDB, TAB at 323 kHz! This was his first received signal with = this=20 receive setup, yesterday! Now he acutually has a reference signal = which comes=20 from the far field. Quickly he found that 60 turns primary were better = than 40=20 and that 80 turns resulted in the same signal strength than 60.... So = far so=20 good...

We tried then to receive the carrier of the 153 khz AM=20 broadcast staions, which worked very well in the first attempt. Slowly = it=20 became dark in YV and so we actually successfully received traces of = DCF39!!!=20 :-) The mile stone! After preparing the grabber page i prepared a = SpecLab file=20 to display DCF39 in 45 mHz over the night. The images were uploaded to = the=20 webpage and saved to a local folder. Now looking to the archive, best = S/N was=20 arround 20 dB (so far without any noise reduction!), seen here on = Martin's=20 dropbox: http://dl.dropbox.com/u/74746618/Pictures%20for%20exchange/DCF39_= 09.jpg

This=20 is a very clear trace but still it looks like lack of sensitivity, so = we have=20 to improve the system further. Also the typical QRN morning dip is not = visible! But anyway a very good result after some days. It shows that = the=20 frequency drift and offset of the 703 is reasonable, also suitable for = QRSS-60=20 detections later. We also checked in a wideband window, covering 0...3 = kHz,=20 i.e. the SSB filter width, that there seems to be no drifting mains = harminics=20 or SMPS sidebands, hopefully not due to lack of sensitivity=20 ;-)

Probably we need an air coil and a well resonated receive = system to=20 generate a higher signal level for the deaf  IC703. He also has = some=20 variable capacitors that look like arround 200 pF or so. So it should = be=20 possible to match the system if it has some Q. This first success with = the=20 SMPS transformer was very important though! Also the absence of strong = QRM=20 makes the project even more promising now.

Luckily Martin has a = internet flatrate, so we worked together on his PC using a Teamviewer = remote=20 connection to install a dropbox, a grabber page and SpecLab, with = automatic=20 jpg upload. It was quite difficult for me since the PC is in Spanish=20 :-)
Who knows, maybe some day he will appear here in the LF = reflector. He=20 is also in a nice local radio club where they have a high tower for a = VHF=20 repeater. Maybe they will add a transmit antenna soon? ;-) Does = someone know=20 about a LF allocation in Venezuela?

Not only for US, UK, and EU = but of=20 course for the southern stations in South america this could be an = interesting=20 new challenge. Soon we will make first tests in the 137 kHz band but = it looks=20 like we have to find another 10 dB S/N from somewhere. Any good ideas? = No, a=20 preamp cannot be built, due to lack of electronic parts! Somehow i = find that=20 all very exciting, i mean not having all the parts available but have = to=20 improvise, maybe like in the very early days! :-)

So let's hope = for=20 continued progress, improvements and interest!

Ah, of course, = the link=20 tho the new Venezuela LF Grabber (still in test mode): http:= //dl.dropbox.com/u/74746618/LF/YV7MAE_LF_Grabber.html
It=20 becomes more interesting at night of course. Local time is UTC-4. So = far a=20 test window of DCF39 is shown but soon we will run a EU60 and/or TA60=20 window.


73, Stefan/DK7FC
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