Return-Path: Received: from mtain-de05.r1000.mx.aol.com (mtain-de05.r1000.mx.aol.com [172.29.64.205]) by air-ma06.mail.aol.com (v129.4) with ESMTP id MAILINMA061-b5284ca0e947368; Mon, 27 Sep 2010 14:58:15 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-de05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7488638000144; Mon, 27 Sep 2010 14:58:13 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1P0IsR-0004Lm-CF for rs_out_1@blacksheep.org; Mon, 27 Sep 2010 19:56:39 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1P0IsG-0004Ld-EY for rsgb_lf_group@blacksheep.org; Mon, 27 Sep 2010 19:56:28 +0100 Received: from out1.ip04ir2.opaltelecom.net ([62.24.128.240]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1P0IsF-0005kj-0j for rsgb_lf_group@blacksheep.org; Mon, 27 Sep 2010 19:56:29 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AkkFAGKFoExOk8J1/2dsb2JhbACWdIU4hW5xyUaCbIJYBIFci3KCTA X-IronPort-AV: E=Sophos;i="4.57,244,1283727600"; d="scan'208,217";a="305934005" Received: from unknown (HELO xphd97xgq27nyf) ([78.147.194.117]) by out1.ip04ir2.opaltelecom.net with SMTP; 27 Sep 2010 19:56:20 +0100 Message-ID: <00a901cb5e75$ab722440$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <4C9D17FF.4040004@iup.uni-heidelberg.de> <003b01cb5e54$43a8f080$0401a8c0@xphd97xgq27nyf> <4CA0DD3B.1090408@iup.uni-heidelberg.de> Date: Mon, 27 Sep 2010 19:56:18 +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: LF: DK7FC now on 137.715 in DFCW4 with his 600m earth antenna Content-Type: multipart/alternative; boundary="----=_NextPart_000_00A6_01CB5E7E.0CEA4100" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.1 required=5.0 tests=HTML_20_30,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY,HTML_TITLE_EMPTY 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: 3039ac1d40cd4ca0e9456ed5 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_00A6_01CB5E7E.0CEA4100 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Stefan I am not surprised to see your signal with my antenna system.=20 I normally use QRS3 setting maybe 10 but not slower and certainly NOT= 600 The ic - 706, with preamp on is good on 137 Kcs with a LARGE antenna= but NO good for small antennas. I use an ic-706 with my vert antenna= system but also have other receivers and antennas. I have a MF/LF/VLF PEGELMESSER which is vy good as a RX and vy good on= 9 Kcs.=20 I am equipped for all eventualities=20 I do not normally make reports on BEACON transmissions except maybe a= new country or something special. I am interested only in QSO mode on same band or xband. My spectrum display on dfcw is reversed on your signal. Your signal wa= s not positive ID without some guesswork therefore does not count for= distance record. G3KEV ----- Original Message -----=20 From: Stefan Sch=E4fer=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Monday, September 27, 2010 7:06 PM Subject: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600m earth= antenna Mal, LF, It is a wire, 4 m above ground. It is grounded at the far end, using= 20 * 0,4 m loong copper rods, about 1m spaced. The same ground electr= ode array is near the other end of the antenna. The RF is applied at= this point, so between one earth electrode and the wire. RF power was= about 100 W in this test.=20 The antenna was not resonated or matched to 50 Ohm but the PA remain= ed absolutely cold, so all the power (measured on the DC side ( P=3D= 12,5 V * 8,5 A)) must have been applied to the antenna. I will take= an Oscilloscope to the antenna soon and will measure the U/I ratio an= d the phase. Then i can add some C and a suitable step up transformer.= If Z=3DR=3D50 Ohm i can apply my class E PA as well... Also, i will built an amperemeter (using a current transformer and= a bridge rectifier) to measure the antenna current on all frequencies= , since my digital amperemeter can measure on 8.97 kHz but not on 137= kHz... Mal, what ARGO settings do you use? QRSS-3, normal should be suitabl= e. My DFCW was 4 seconds dot and 1 second break between the elements.= I am using RIKs QRS program. Will switch to QRSS the next time (not= only but sometimes ;-) ). On sunday i have tested the IC-706 as a RX. For attenuation a had ju= st the possibility to use the internal attenuator. But this is all sti= ll not working fine. I could not even receive OE5ODL. So i have to wor= k on this side... Has anyone a ready to use circuit for a homemade LF RX that uses a= high power signal? LF RX means that i do not need an extra HF TRX to= make signals audible. So the signal must be shifted down to the range= where the soundcard is working or even to audible frequencies. And th= e input should be suitable for strong signals... :-) 73, es CU Stefan/DK7FC Am 27.09.2010 16:57, schrieb mal hamilton:=20 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 some sort. or is it two long insulated wires lying on the ground and each wire= grounded 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= because the elements were too close together, more spacing between el= ements 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 ----- 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 600= m earth antenna ---------- Forwarded message ---------- From: Stefan Sch=E4fer Date: 2010/9/24 Subject: Fwd: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600= m earth antenna To: Roger Lapthorn Hello Roger, Below you find my eport on the todays LF earth antennas test. Cu= rrently 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= was 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 ante= nna as a TX antenna on LF. But knowing that my small PA for VLF (12V/3= 00W 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 small= er than on VLF but the big advantage seems to be that the antenna is= even longer than lambda/4 for 2200m! Thus, to my surprise, and probab= ly to the surprise of the most of you, the antenna seems to be very su= itable as a TX antenna although the average height of the wire above= ground is just about 4m!! The ground resistance is about 600 Ohm, cur= rently. 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 DD7P= C grabber, about 20 dB above noise in DFCW-3, distance is 77 km. So,= it must 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= antenna. It is months ago that i tried to convince some people here= to try such an antenna. Maybe this day can help to convince practical= oriented people that it is worth trying things that seems to be "wast= ed time" 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 parent= s 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 ear= th 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 ma= ybe have a preferred direction. YOU all can help to find out this radi= ation pattern by listening to my transmissions that will be done in th= e 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= during 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_00A6_01CB5E7E.0CEA4100 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Stefan
I am not surprised to see your signal= with my=20 antenna system.
 
I normally use QRS3 setting maybe 10= but not slower=20 and certainly NOT 600
 
The ic - 706, with preamp on &nb= sp;is good on=20 137 Kcs with a LARGE antenna but NO good for small antennas. I use an= ic-706=20 with my vert antenna system but also have other receivers and=20 antennas.
 
I have a MF/LF/VLF PEGELMESSER which= is vy good as=20 a RX and vy good on 9 Kcs.
 
I am equipped for all eventualities=
 
I do not normally make reports= on BEACON=20 transmissions except maybe a new country or something special.<= /DIV>
 
I am interested only in QSO mode on= same band or=20 xband.
 
My spectrum display on dfcw is revers= ed on your=20 signal. Your signal was not positive ID without some guesswork therefo= re does=20 not count for distance record.
 
 
G3KEV
 
 
 
----- Original Message -----
Sent: Monday, September 27,= 2010 7:06=20 PM
Subject: Re: LF: DK7FC now on= 137.715 in=20 DFCW4 with his 600m earth antenna

Mal, LF,

It is a wire, 4 m above ground. It is= grounded=20 at the far end, using 20 * 0,4 m loong copper rods, about 1m spaced.= The same=20 ground electrode array is near the other end of the antenna. The RF= is applied=20 at this point, so between one earth electrode and the wire. RF power= was about=20 100 W in this test.

The antenna was not resonated or matched= to 50 Ohm=20 but the PA remained absolutely cold, so all the power (measured on= the DC side=20 ( P=3D 12,5 V * 8,5 A)) must have been applied to the antenna. I wil= l take an=20 Oscilloscope to the antenna soon and will measure the U/I ratio and= the phase.=20 Then i can add some C and a suitable step up transformer. If Z=3DR= =3D50 Ohm i can=20 apply my class E PA as well...

Also, i will built an ampereme= ter (using=20 a current transformer and a bridge rectifier) to measure the antenna= current=20 on all frequencies, since my digital amperemeter can measure on 8.97= kHz but=20 not on 137 kHz...

Mal, what ARGO settings do you use? QRSS-3,= normal=20 should be suitable. My DFCW was 4 seconds dot and 1 second break bet= ween the=20 elements. I am using RIKs QRS program. Will switch to QRSS the next= time (not=20 only but sometimes ;-) ).

On sunday i have tested the IC-706= as a RX.=20 For attenuation a had just the possibility to use the internal atten= uator. But=20 this is all still not working fine. I could not even receive OE5ODL.= So i have=20 to work on this side...

Has anyone a ready to use circuit for= a=20 homemade LF RX that uses a high power signal? LF RX means that i do= not need=20 an extra HF TRX to make signals audible. So the signal must be shift= ed down to=20 the range where the soundcard is working or even to audible frequenc= ies. And=20 the input should be suitable for strong signals... :-)

73, es= =20 CU

Stefan/DK7FC


Am 27.09.2010 16:57, schrieb mal= hamilton:=20
I see some confusion here as rega= rds Earth=20 antennas.
Is this antenna a wire x metres= above ground=20 and grounded at one end and fed with rf at the other ? if so then= it is a=20 grounded loop of some sort.
 
or
 
is it two long insulated wir= es lying on=20 the ground and each wire grounded by a stake at one end and the ot= her end=20 pair fed with rf ?
 
Please be more clear about this= type of antenna=20 system.
 
I was able to see some DFCW signa= l broken up on=20 Friday but no ID because the elements were too close together, mor= e spacing=20 between elements or QRS 10 and I could have got an ID
 
A missed opportunity for a DX rep= ort, the=20 signal could have been DK7FC because of the QRG and QTR = but this=20 is NOT proof of signal.
I have a couple of screen shots= as proof of=20 a signal.
 
 
de G3KEV
 
-----=20 Original Message -----
From:=20 Roger Lapthorn
Sent:=20 Saturday, September 25, 2010 12:28 PM
Subject:=20 Fwd: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600m earth= =20 antenna

---------- Forwarded message ----------
From: Stefa= n Sch=E4fer=20 <schaefer@iup.uni-heidelberg.de<= /A>>
Date:=20 2010/9/24
Subject: Fwd: Re: LF: DK7FC now on 137.715 in DFCW4= with his=20 600m earth antenna
To: Roger Lapthorn <roger= lapthorn@gmail.com>


Hello Roger,

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

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

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

Best 73, Stefan/DK7FC

-------- Original-Nachri= cht=20 --------=20
Betreff: Re: LF: DK7FC now on 137.715 in DFCW4 with his 600m eart= h=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@abeli= an.netcom.co.uk>


Hello=20 Marco, Michel, John, LF,

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

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

We know that the effective ar= ea of the=20 formed loop must be smaller than on VLF but the big advantage se= ems to be=20 that the antenna is even longer than lambda/4 for 2200m! Thus,= to my=20 surprise, and probably to the surprise of the most of you, the= antenna=20 seems to be very suitable as a TX antenna although the average= height of=20 the wire above ground is just about 4m!! The ground resistance= is about=20 600 Ohm, currently.
I am VERY happy now to have a fixed anten= na in a=20 quiet location that does not matter of rain and wind or so and= can be used=20 from DC to HF :-)
A first transmission at 25 W was im= mediately=20 visible on the DD7PC grabber, about 20 dB above noise in DFCW= -3,=20 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. Man= y TNX to=20 Michel and John! If the signal was 20 dB above noise in DFCW-3= at John's=20 QTH in JN17VG (436 km), it must have been audible as well= !=20 :-)

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

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

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

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

So, there was a discussion about the radiation= pattern of=20 an earth antenna, if it acts as a loop or not. Since the antenna= length is=20 in the region a lambda, it surely will not be a pure loop and wi= ll maybe=20 have a preferred direction. YOU all can help to find out this ra= diation=20 pattern by listening to my transmissions that will be done in th= e next=20 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 Oexne= r again=20 and later on LF i would appreciate any rprts. But still not sure= if i can=20 come to QSO mode, due to the RX.

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

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

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

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


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

Stefan/DK7FC




Am 24.09.2010 17= :27,=20 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



  
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.
    
  
Vy73
Marco
DD7PC


--=20
http://g3xbm-qrp.blogspot.com/http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
G3XBM = ; =20 GQRP 1678    ISWL=20 G11088
------=_NextPart_000_00A6_01CB5E7E.0CEA4100--