Return-Path: Received: from mtain-dh12.r1000.mx.aol.com (mtain-dh12.r1000.mx.aol.com [172.29.65.32]) by air-md05.mail.aol.com (v129.4) with ESMTP id MAILINMD051-8b844ca0b24e31c; Mon, 27 Sep 2010 11:03:42 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dh12.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1D594380079B7; Mon, 27 Sep 2010 10:59:04 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1P0F91-0001HG-Vg for rs_out_1@blacksheep.org; Mon, 27 Sep 2010 15:57:31 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1P0F8r-0001H7-7x for rsgb_lf_group@blacksheep.org; Mon, 27 Sep 2010 15:57:21 +0100 Received: from out1.ip03ir2.opaltelecom.net ([62.24.128.239]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1P0F8p-00049Y-Bc for rsgb_lf_group@blacksheep.org; Mon, 27 Sep 2010 15:57:22 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AlsFAJpNoExOk8J1/2dsb2JhbACQQAOGSosmcccThUQEgVyLcoJM X-IronPort-AV: E=Sophos;i="4.57,243,1283727600"; d="scan'208,217";a="319584536" Received: from unknown (HELO xphd97xgq27nyf) ([78.147.194.117]) by out1.ip03ir2.opaltelecom.net with SMTP; 27 Sep 2010 15:57:12 +0100 Message-ID: <003b01cb5e54$43a8f080$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <4C9D17FF.4040004@iup.uni-heidelberg.de> Date: Mon, 27 Sep 2010 15:57:10 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.1 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,HTML_TAG_EXIST_TBODY=0.126 Subject: Re: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600m earth antenna Content-Type: multipart/alternative; boundary="----=_NextPart_000_0038_01CB5E5C.A4FFC9A0" 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, 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 x-aol-global-disposition: S X-AOL-REROUTE: YES x-aol-sid: 3039ac1d41204ca0b1380c4f X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_0038_01CB5E5C.A4FFC9A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I see some confusion here as regards Earth antennas. Is this antenna a wire x metres above ground and grounded at one end= and fed with rf at the other ? if so then it is a grounded loop of so= me sort. or is it two long insulated wires lying on the ground and each wire groun= ded by a stake at one end and the other end pair fed with rf ? Please be more clear about this type of antenna system. I was able to see some DFCW signal broken up on Friday but no ID becau= se the elements were too close together, more spacing between elements= or QRS 10 and I could have got an ID A missed opportunity for a DX report, the signal could have been DK7FC= because of the QRG and QTR but this is NOT proof of signal. I have a couple of screen shots as proof of a signal. de G3KEV =20 ----- Original Message -----=20 From: Roger Lapthorn=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Saturday, September 25, 2010 12:28 PM Subject: Fwd: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600m ea= rth antenna ---------- Forwarded message ---------- From: Stefan Sch=E4fer Date: 2010/9/24 Subject: Fwd: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600m ea= rth antenna To: Roger Lapthorn Hello Roger, Below you find my eport on the todays LF earth antennas test. Curren= tly it seems not possible for me to send to the reflector. I even do= not get mails from there... (?) Markus/DF6NM has forwarded the mail to the reflector but it wasn't= reflected. Maybe, you can try to forward it? Can you tell me if it wa= s reflected? The mail contains some infos about my todays activity on VLF/LF! So= could be interesting to some RX stations :-) Best 73, Stefan/DK7FC -------- Original-Nachricht -------- Betreff: Re: LF: DK7FC now on= 137.715 in DFCW4 with his 600m earth antenna=20 Datum: Fri, 24 Sep 2010 22:02:59 +0200=20 Von: Stefan Sch=E4fer =20 An: Renato Romero , Paul =20 Hello Marco, Michel, John, LF, This is a great day for the optimists, regarding EARTH ANTENNAs as= a TX antenna! :-) Until today i have not spend too much attention to my earth antenna= as a TX antenna on LF. But knowing that my small PA for VLF (12V/300W= class D) can also transmit on 137 kHz i gave it a first try today. I= was almost sure that my signal will be visible on my grabber in 5 km= distance but wasn't sure how the efficiency really is... We know that the effective area of the formed loop must be smaller= than on VLF but the big advantage seems to be that the antenna is eve= n longer than lambda/4 for 2200m! Thus, to my surprise, and probably= to the surprise of the most of you, the antenna seems to be very suit= able as a TX antenna although the average height of the wire above gro= und is just about 4m!! The ground resistance is about 600 Ohm, current= ly. I am VERY happy now to have a fixed antenna in a quiet location that= does not matter of rain and wind or so and can be used from DC to HF= :-)=20 A first transmission at 25 W was immediately visible on the DD7PC gr= abber, about 20 dB above noise in DFCW-3, distance is 77 km. So, it mu= st have been audible! A later transmission at 100 W is visible in France, with a good S/N.= Many TNX to Michel and John! If the signal was 20 dB above noise in= DFCW-3 at John's QTH in JN17VG (436 km), it must have been audible as= well! :-) Indeed, i have also never expected this efficiency from an earth ant= enna. It is months ago that i tried to convince some people here to tr= y such an antenna. Maybe this day can help to convince practical orien= ted people that it is worth trying things that seems to be "wasted tim= e" and/or "impossible" :-)))=20 I also hope that an earth antenna will be seen as an alternative to= a normal closed loop or a vertical, especially in a woody region. Attached you find a screenshot of my grabber and my signal in 5 km= distance. Maybe it was 100 dB above noise? ;-))) I still have no RX that can handle this big input signal. My 706 is= not the best idea and i have most of my LF equipment on the parents= QTH but i will try to receive tomorrow with the 706 and my PC on the= earth antenna, using some attenuators and/or transformers. I will bui= ld a suitable RX for this antenna soon. But the QTH is EXCELLENT as yo= u can image :-) So, there was a discussion about the radiation pattern of an earth= antenna, if it acts as a loop or not. Since the antenna length is in= the region a lambda, it surely will not be a pure loop and will maybe= have a preferred direction. YOU all can help to find out this radiati= on pattern by listening to my transmissions that will be done in the= next days. Tomorrow, arround 8 UTC i will do a VLF test and later a= LF test on the earth antenna. The VLF test is to reach Michael Oexner= again and later on LF i would appreciate any rprts. But still not sur= e if i can come to QSO mode, due to the RX. Now i know that this antenna is very worth to keep and improve. This= will be done in the next weeks! :-) BTW: I cannot transmit on sunday with the kite antenna, due to the= WX, sri... If some people want to try an earth antenna as a TX antenna, you can= ask me any questions!=20 Sorry, i am a little euphoric now. The best sign if this happens dur= ing a project. Can it be wasted time then? Best 73 and hope cuagn on LF this period!=20 Stefan/DK7FC Am 24.09.2010 17:27, schrieb Michel Brunel:=20 Hello Marco, LF, Excellent copy here in JN18HP, hope the capture find its way through= the reflector.=20 I was definitely not expecting such a signal with an earth electrode= ! 73 Michel - F5WK =20 Hello LF, Stefan, DK7FC is transmitting with his 600m earth antenna on +/- 137.7= 15KHz in DFCW4. I could see him on my Grabber (see attachment) http://www.qsl.net/dd7pc/lfgrabber_dd7pc.html and on the grabber from Markus, DF6NM with a very good signal. He was transmitting just with 25W and will increase now to 100W. Any reports of his transmission are very welcome. =20 =20 Vy73 Marco DD7PC =20 --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 ------=_NextPart_000_0038_01CB5E5C.A4FFC9A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I see some confusion here as regards= Earth=20 antennas.
Is this antenna a wire x metres above= ground and=20 grounded at one end and fed with rf at the other ? if so then it is a= grounded=20 loop of some sort.
 
or
 
is it two long insulated wires= lying on the=20 ground and each wire grounded by a stake at one end and the other end= =20 pair fed with rf ?
 
Please be more clear about this type= of antenna=20 system.
 
I was able to see some DFCW signal br= oken up on=20 Friday but no ID because the elements were too close together, more sp= acing=20 between elements or QRS 10 and I could have got an ID
 
A missed opportunity for a DX report,= the signal=20 could have been DK7FC because of the QRG and QTR but this is= NOT proof=20 of signal.
I have a couple of screen shots as pr= oof of=20 a signal.
 
 
de G3KEV
 
----- Original Message -----
Sent: Saturday, September 25,= 2010 12:28=20 PM
Subject: Fwd: Re: LF: DK7FC= now on=20 137.715 in DFCW4 with his 600m earth antenna

---------- Forwarded message ----------
From: Stefan Sc= h=E4fer=20 <schaefer@iup.uni-heidelberg.de>
Date:=20 2010/9/24
Subject: Fwd: Re: LF: DK7FC now on 137.715 in DFCW4 wit= h his 600m=20 earth antenna
To: Roger Lapthorn <rogerlapthorn@gmail.com>


Hello Roger,

Below= you find my=20 eport on the todays LF earth antennas test. Currently it seems not= possible=20 for me to send to the reflector. I even do not get mails from there.= ..=20 (?)

Markus/DF6NM has forwarded the mail to the reflector but= it wasn't=20 reflected. Maybe, you can try to forward it? Can you tell me if it= was=20 reflected?

The mail contains some infos about my todays activ= ity on=20 VLF/LF! So could be interesting to some RX stations :-)

Best= 73,=20 Stefan/DK7FC

-------- Original-Nachricht --------=20
Betreff: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600m earth=20 antenna
Datum: Fri, 24 Sep 2010 22:02:59 +0200
Von: Stefan Sch=E4fer <schaefer@iup.uni-heidelberg.de>= ;
An: Renato Romero <contact@vlf.it>, Paul <paul@abe= lian.netcom.co.uk>


Hello=20 Marco, Michel, John, LF,

This is a great day for the optimist= s,=20 regarding EARTH ANTENNAs as a TX antenna! :-)

Until to= day i have=20 not spend too much attention to my earth antenna as a TX antenna on= LF. But=20 knowing that my small PA for VLF (12V/300W class D) can also transmi= t on 137=20 kHz i gave it a first try today. I was almost sure that my signal wi= ll be=20 visible on my grabber in 5 km distance but wasn't sure how the effic= iency=20 really is...

We know that the effective area of the formed lo= op must be=20 smaller than on VLF but the big advantage seems to be that the anten= na is even=20 longer than lambda/4 for 2200m! Thus, to my surprise, and probably= to the=20 surprise of the most of you, the antenna seems to be very suitable= as a TX=20 antenna although the average height of the wire above ground is just= about=20 4m!! The ground resistance is about 600 Ohm, currently.
I am VERY= happy now=20 to have a fixed antenna in a quiet location that does not matter of= rain and=20 wind or so and can be used from DC to HF :-)
A first transmissio= n at 25=20 W was immediately visible on the DD7PC grabber, about 20 dB= above noise=20 in DFCW-3, distance is 77 km. So, it must have been audible!
= A later=20 transmission at 100 W is visible in France, with a good S/N. Many TN= X to=20 Michel and John! If the signal was 20 dB above noise in DFCW-3 at Jo= hn's QTH=20 in JN17VG (436 km), it must have been audible as well!=20 :-)

Indeed, i have also never expected this efficiency from= an earth=20 antenna. It is months ago that i tried to convince some people here= to try=20 such an antenna. Maybe this day can help to convince practical orien= ted people=20 that it is worth trying things that seems to be "wasted time" and/or= =20 "impossible" :-)))

I also hope that an earth antenna will be= seen as=20 an alternative to a normal closed loop or a vertical, especially in= a woody=20 region.

Attached you find a screenshot of my grabber and my= signal in 5=20 km distance. Maybe it was 100 dB above noise? ;-)))

I still= have no RX=20 that can handle this big input signal. My 706 is not the best idea= and i have=20 most of my LF equipment on the parents QTH but i will try to receive= tomorrow=20 with the 706 and my PC on the earth antenna, using some attenuators= and/or=20 transformers. I will build a suitable RX for this antenna soon. But= the QTH is=20 EXCELLENT as you can image :-)

So, there was a discussion abo= ut the=20 radiation pattern of an earth antenna, if it acts as a loop or not.= Since the=20 antenna length is in the region a lambda, it surely will not be a pu= re loop=20 and will maybe have a preferred direction. YOU all can help to find= out this=20 radiation pattern by listening to my transmissions that will be done= in the=20 next days. Tomorrow, arround 8 UTC i will do a VLF test and later= a LF test=20 on the earth antenna. The VLF test is to reach Michael Oexner ag= ain and=20 later on LF i would appreciate any rprts. But still not sure if i ca= n come to=20 QSO mode, due to the RX.

Now i know that this antenna is very= worth to=20 keep and improve. This will be done in the next weeks! :-)

BTW: I=20 cannot transmit on sunday with the kite antenna, due to the WX,=20 sri...

If some people want to try an earth antenna as a= TX antenna,=20 you can ask me any questions!

Sorry, i am a little euphoric= now. The=20 best sign if this happens during a project. Can it be wasted time=20 then?


Best 73 and hope cuagn on LF this period!=20

Stefan/DK7FC




Am 24.09.2010 17:27, schrieb= Michel=20 Brunel:=20 
Hello Marco, LF,

Excellent copy here in JN18HP, hope the capture find its way through=
 the
reflector.=20
I was definitely not expecting such a signal with an earth electrode=
 !

73

Michel - F5WK



  
Hello LF,
Stefan, DK7FC is transmitting with his 600m earth antenna on +/- 137.7=
15KHz in DFCW4.
I could see him on my Grabber (see attachment)
http://www.qsl.net/dd7pc/lfgrabber_dd7pc.html and on the grabb=
er from
Markus, DF6NM with a very good signal.
He was transmitting just with 25W and will increase now to 100W.
Any reports of his transmission are very welcome.
    
  
Vy73
Marco
DD7PC


--=20
h= ttp://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube= .com/user/g3xbm
G3XBM   GQRP=20 1678    ISWL G11088
------=_NextPart_000_0038_01CB5E5C.A4FFC9A0--