Return-Path: Received: from mtain-md11.r1000.mx.aol.com (mtain-md11.r1000.mx.aol.com [172.29.96.95]) by air-me08.mail.aol.com (v128.1) with ESMTP id MAILINME082-8bbd4bba32a0297; Mon, 05 Apr 2010 14:57:36 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-md11.r1000.mx.aol.com (Internet Inbound) with ESMTP id 91656380000E1; Mon, 5 Apr 2010 14:57:34 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NyrTc-0003k3-Rx for rs_out_1@blacksheep.org; Mon, 05 Apr 2010 19:56:48 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NyrTb-0003ju-WE for rsgb_lf_group@blacksheep.org; Mon, 05 Apr 2010 19:56:48 +0100 Received: from cavuit01.kulnet.kuleuven.be ([134.58.240.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NyrTY-0006fg-Iw for rsgb_lf_group@blacksheep.org; Mon, 05 Apr 2010 19:56:47 +0100 Received: from smtps01.kuleuven.be (smtpshost01.kulnet.kuleuven.be [134.58.240.74]) by cavuit01.kulnet.kuleuven.be (Postfix) with ESMTP id 091737B802A for ; Mon, 5 Apr 2010 20:56:37 +0200 (CEST) Received: from ICTS-S-HUB-N3.luna.kuleuven.be (icts-s-hub-n3.luna.kuleuven.be [10.112.9.13]) by smtps01.kuleuven.be (Postfix) with ESMTP id E1E1D31E702 for ; Mon, 5 Apr 2010 20:56:36 +0200 (CEST) Received: from ICTS-S-EXC2-CA.luna.kuleuven.be ([10.112.11.13]) by ICTS-S-HUB-N3.luna.kuleuven.be ([10.112.9.13]) with mapi; Mon, 5 Apr 2010 20:56:36 +0200 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Date: Mon, 5 Apr 2010 20:52:58 +0200 Thread-Topic: RE: RE: W1VLF 9 Khz Antenna update Putting inductance near the top. Thread-Index: AcrT35yWRmHp8hCST8Ccpvq77MwkpwADIb1OAAYNgSAABDjxzwAHEICAAAM9Z5gAItoBowAJ1jGg Message-ID: References: <38A51B74B884D74083D7950AD0DD85E82A1BD1@File-Server-HST.hst.e-technik.tu-darmstadt.de>, ,<38A51B74B884D74083D7950AD0DD85E82A1BD6@File-Server-HST.hst.e-technik.tu-darmstadt.de> In-Reply-To: <38A51B74B884D74083D7950AD0DD85E82A1BD6@File-Server-HST.hst.e-technik.tu-darmstadt.de> Accept-Language: nl-NL, nl-BE Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: nl-NL, nl-BE MIME-Version: 1.0 X-KULeuven-Information: Katholieke Universiteit Leuven X-KULeuven-Scanned: Found to be clean X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: RE: RE: RE: W1VLF 9 Khz Antenna update Putting inductance near the top. Content-Type: multipart/alternative; boundary="_000_BF4A524700075746A6467658DFC7102C19A043E518ICTSSEXC2CAlu_" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_40_50,HTML_FONTCOLOR_BLUE, HTML_MESSAGE,TO_ADDRESS_EQ_REAL 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-sid: 3039ac1d605f4bba329e331b X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --_000_BF4A524700075746A6467658DFC7102C19A043E518ICTSSEXC2CAlu_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Stefan, as you can read in mine and other mail an elevated loading coil can improv= e the antenna on 137 and 500kHz. It is likely that it will have the same effect on 9kHz, but so far there= is no hard prove. I gues the only way to find out is to try it. Or as they say in German: Probieren geht =FCber studieren. 73, Rik ON7YD - OR7T ________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.or= g] namens Stefan Sch=E4fer [schaefer@hst.tu-darmstadt.de] Verzonden: maandag 5 april 2010 16:26 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: AW: RE: RE: W1VLF 9 Khz Antenna update Putting inductance= near the top. Hi Rik, I think on VLF it could be even useful to place the L as high as possible= when there is "nothing" lossy in the near surrounding. I think the differ= ence to LF is, that the coil losses on VLF can be some 100 Ohms. If the "l= ost" capacitive current, that comes out of the lower part of the vertical= section comes back to the coil without crossing too much earth resistance= (due to the short way back to the coil) and if the coil losses are low (o= n LF often in the near of 10 Ohm), there is not much lost and it behaves= almost as a fixed parallel C (assembly part). Thus the benefit is rather= small. On VLF, the same equivalent capacitance causes much more losses due to the= higher coil resistance. The Xc is higher but U also. I have not practically proven that and maybe the effort is not worth, don'= t know. Sometimes it is better just to generate some 10W more power than installin= g a structure that will break down in the next storm ;-) 73, Stefan/DK7FC ________________________________ Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von Rik Strobbe Gesendet: So 04.04.2010 23:40 An: rsgb_lf_group@blacksheep.org Betreff: LF: RE: RE: W1VLF 9 Khz Antenna update Putting inductance near th= e top. Hello Paul, after I published my experiences several hams tried elevated loading coils= on 137kHz. Significant improvement was observed when the antenna was surrounded by hi= gh obstacles (trees, buildings), when the antenna was "free" there was lit= tle or no gain. I have no idea what the effect will be on 9kHz, but if you can install an= elevated loading coil it whitout too much effort I would suggest to try= it. In my case most stations noticed a signal increase of about 1 S point and= PA0SE measured the field strength and noticed a difference of 5dB. 73, Rik ON7YD - OR7T ________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.or= g] namens Paul A. Cianciolo [paulc@snet.net] Verzonden: zondag 4 april 2010 22:28 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: RE: W1VLF 9 Khz Antenna update Putting inductance near the= top. Stefan On page 60 and 61 of the Low Frequency Experimenters Handbook Peter Dodd= RSGB there is an example putting a coil near the top of the antenna In this case the transmitter is on 137 Khz and a of a portion (1/2) of the= "L" needed to resonate was moved near the top. According to measurements= by Rik Strobbe ON7YD an increase of 4 to 5 db was measured. Do you think it would be worth the effort to put 1/4 of the total "L" need= ed near the top I could do that very easily. PaulC W1VLF -----Original Message----- From: Stefan Sch=E4fer [mailto:owner-rsgb_lf_group@blacksheep.org]On Behal= f Of Stefan Sch=E4fer Sent: Sunday, April 04, 2010 12:49 PM To: rsgb_lf_group@blacksheep.org Subject: AW: W1VLF 9 Khz Antenna update Hello Paul, This sounds really improving!! And this will give a much more efficient an= tenna as before. Also the HV problems will be reduced. Note that the goal= should not be to make the C as high as possible but first to make the ant= enna efficiency as high as possible. This is done be increasing the effect= ive height and reducing all the losses. Thus i would recommend now a combi= nation out of option 2 and 3. Maybe you could check with G3YNKs R-C bridge= , if the losses are increased with option 3. You could use a braid of some= meters to keep a distance to the trees although the wire is mounted on th= e trees. But all in all it sounds very promising! Option 1 is not so much improving i would say. The C would slightly increa= se but not the antenna efficiency i mean... What about the option to place the coil on the 40m tower? That would be th= e best improvement you can do! Good luck! Do you already know who could be the next receiving ham station? ;-) 73, Stefan/DK7FC ________________________________ Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von Paul A. Cianciolo Gesendet: So 04.04.2010 17:18 An: rsgb_lf_group@blacksheep.org Betreff: LF: W1VLF 9 Khz Antenna update Stefan,Group. An update on the W1VLF hopefully to be 9 KHZ antenna. The 55 meter wire sloping at 45 degrees measured 340 pf as you recall. The addition of 2 top hat wires has been made, each over 50 meters long wi= th a slope to the ground. Wire 1 is terminates at 11 meters above the ground and wire 2 terminates= 20 meters above the ground. Antenna only =3D 340 pf Antenna and Wire 1 West =3D 650 pf Antenna and wire 1 West and wire 2 East =3D 900 pf L to resonate at 9 KHZ now =3D 350 mHy. The L is now coming down to a reasonable size!! For the next step there are 3 possibilities: 1) Change the top 30 meters from a single wire, to 3 wires spread 1 meter= apart at the top to gain perhaps 100 more PF? 2) Get my neighbors permission to use his tree as a support for the end ro= pe on wire 1. This will increase wire 1 west about 40 meters and raise= the end from 10 meters to 20 meters. 200 PF more? 3) Run 2 more wires Wire 3 Northwest and Wire 4 Northeast each would be= 20 to 30 meters long and terminate at 30 meters high. These would be ov= er a forest and I am not sure if this is my best option. It may yield more "C" and lot more losses?? Goal is to try to get antenna "C" to 1200 pf or more All ideas welcome. PauLC W1VLF -----Original Message----- From: Stefan Sch=E4fer [mailto:owner-rsgb_lf_group@blacksheep.org]On Behal= f Of Stefan Sch=E4fer Sent: Sunday, April 04, 2010 7:44 AM To: rsgb_lf_group@blacksheep.org Subject: AW: Activity 3 Mar 2010 Mike, LF, Wow! 5641km is really impressing! Congrats!! Is there such an activity planned for the "west-stations" as well? We coul= d do the same! I've never been slower than DFCW-10 on LF. Would be interesting :-) 73, Stefan/DK7FC ________________________________ Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von Mike Dennison Gesendet: So 04.04.2010 12:09 An: rsgb_lf_group@blacksheep.org Betreff: LF: Activity 3 Mar 2010 An excellent day's activity on 137kHz yesterday with 5 countries received, the furthest easterly station received here and a QSO with a new country. In the morining, OE5ODL and DJ6GT were received. During the UA tests, five stations were logged (see the attached screen grab - Argo set to QRSS30 and centred on 137.778kHz). The picture shows (from the top) UA0AET (5641km from me); RA3YO; RN3AGC; UA4WPF; and EW6GB who was first received as early as 1700UTC. After the formal test I exchanged 'O' reports with EW6GB at 1902km, using QRSS10. Well done to all concerned. Mike, G3XDV =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --_000_BF4A524700075746A6467658DFC7102C19A043E518ICTSSEXC2CAlu_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Ste= fan,
 
as you can read in mine= and other mail an elevated loading coil can improve the antenna on= 137 and 500kHz.
It is likely that it wil= l have the same effect on 9kHz, but so far there is no hard prove.<= /div>
I gues the only way to= find out is to try it.
Or as they say in German= : Probieren geht =FCber studieren.
 
73, Rik  ON7YD - OR= 7T 
 
Van: owner-rsgb_lf_group@blackshee= p.org [owner-rsgb_lf_group@blacksheep.org] namens Stefan Sch=E4fer [schaef= er@hst.tu-darmstadt.de]
Verzonden: maandag 5 april 2010 16:26
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: LF: AW: RE: RE: W1VLF 9 Khz Antenna update Putting induc= tance near the top.

Hi Rik,=
 
I think on VLF it could= be even useful to place the L as high as possible when there is "not= hing" lossy in the near surrounding. I think the difference to LF is,= that the coil losses on VLF can be some 100 Ohms. If the "lost" capacitive current, that comes out of the lower part= of the vertical section comes back to the coil without crossing too much= earth resistance (due to the short way back to the coil) and if the coil= losses are low (on LF often in the near of 10 Ohm), there is not much lost and it behaves almost as a fixed parall= el C (assembly part). Thus the benefit is rather small.
On VLF, the same equivale= nt capacitance causes much more losses due to the higher coil resistance.= The Xc is higher but U also.
I have not practically pr= oven that and maybe the effort is not worth, don't know.
 
Sometimes it is better ju= st to generate some 10W more power than installing a structure that will= break down in the next storm ;-)
 
73, Stefan/DK7FC

Von: owner-rsgb_lf_group@blackshee= p.org im Auftrag von Rik Strobbe
Gesendet: So 04.04.2010 23:40
An: rsgb_lf_group@blacksheep.org
Betreff: LF: RE: RE: W1VLF 9 Khz Antenna update Putting inductance= near the top.

Hello= Paul,
 
after I published my exp= eriences several hams tried elevated loading coils on 137kHz.
Significant improve= ment was observed when the antenna was surrounded by high obstacles (trees= , buildings), when the antenna was "free" there was little or no= gain.
I have no idea what the= effect will be on 9kHz, but if you can install an elevated loading coil&n= bsp;it whitout too much effort I would suggest to try it.
In my case most stations=   noticed a signal increase of about 1 S point and PA0SE measured the= field strength and noticed a difference of 5dB.
 
73, Rik  ON7YD - OR= 7T
 
Van: owner-rsgb_lf_group@blackshee= p.org [owner-rsgb_lf_group@blacksheep.org] namens Paul A. Cianciolo [paulc= @snet.net]
Verzonden: zondag 4 april 2010 22:28
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: LF: RE: W1VLF 9 Khz Antenna update Putting inductance ne= ar the top.

Stefan
 
On page 60 and 61 of the Low Frequency Experimenters Handbook Peter Dodd= RSGB  there is an example putting a coil near the top of the antenna=
In this case the transmitter is on 137 Khz and a of a portion (1/2) of th= e "L" needed to resonate was moved near the top. According= to measurements by Rik Strobbe ON7YD  an increase of 4 to 5 db  was measured.
 
Do you think it would be worth the effort to put 1/4 of the total "L= " needed near the top
I could do that very easily.
 
PaulC
W1VLF
 
-----Original Message-----
From: Stefan Sch=E4fer [mailto:owner-rsgb_lf_group@blacksheep.org]<= b>On Behalf Of Stefan Sch=E4fer
Sent: Sunday, April 04, 2010 12:49 PM
To: rsgb_lf_group@blacksheep.org
Subject: AW: W1VLF 9 Khz Antenna update

Hello= Paul,
 
This sounds really improv= ing!! And this will give a much more efficient antenna as before. Also the= HV problems will be reduced. Note that the goal should not be to make the= C as high as possible but first to make the antenna efficiency as high as possible. This is done be increasing th= e effective height and reducing all the losses. Thus i would recommend now= a combination out of option 2 and 3. Maybe you could check with G3YNKs R-= C bridge, if the losses are increased with option 3. You could use a braid of some meters to keep a distance to= the trees although the wire is mounted on the trees.
But all in all it sounds= very promising!
Option 1 is not so much= improving i would say. The C would slightly increase but not the antenna= efficiency i mean...
 
What about the option to= place the coil on the 40m tower? That would be the best improvement you= can do!
 
Good luck!
 
Do you already know who= could be the next receiving ham station? ;-)
 
73, Stefan/DK7FC

Von: owner-rsgb_lf_group@blackshee= p.org im Auftrag von Paul A. Cianciolo
Gesendet: So 04.04.2010 17:18
An: rsgb_lf_group@blacksheep.org
Betreff: LF: W1VLF 9 Khz Antenna update

Stefan,Group.
 
An update on the W1VLF hopefully to be 9 KHZ antenna.
 
 
The 55 meter wire sloping at 45 degrees measured 340 pf as you recal= l.
The addition of 2 top hat wires has been made, each over 50 meters long= with a slope to the ground.
 
Wire 1 is terminates at 11 meters above the ground and wire 2 terminates= 20 meters above the ground.
 
Antenna only =3D 340 pf
 
Antenna and  Wire 1 West  =3D 650 pf
 
Antenna and  wire 1 West and wire 2  East  =3D 900 pf
 
L to resonate at 9 KHZ now =3D 350 mHy.
 
 
The L is now coming down to a reasonable size!!
 
For the next step there are 3 possibilities:
 
1) Change the top 30 meters from a single wire,  to 3 wires spread= 1 meter apart at the top to gain perhaps 100 more PF?<= /div>
 
 
2) Get my neighbors permission to use his tree as a support for the end= rope on wire 1.  This will increase wire 1 west  about 40 meter= s and raise the end from 10 meters to 20 meters. 200 PF more?
 
 
3) Run 2 more wires  Wire 3 Northwest and Wire 4 Northeast  eac= h would be 20 to 30 meters long and terminate at 30 meters high. &nbs= p; These would be over a forest and I am not sure if this is my best option.
It may yield more "C" and lot more losses??
 
Goal is to try to get antenna "C" to 1200 pf or more
 
All ideas welcome.
 
PauLC
W1VLF
 
 
 
-----Original Message-----
From: Stefan Sch=E4fer [mailto:owner-rsgb_lf_group@blacksheep.org]<= b>On Behalf Of Stefan Sch=E4fer
Sent: Sunday, April 04, 2010 7:44 AM
To: rsgb_lf_group@blacksheep.org
Subject: AW: Activity 3 Mar 2010

Mike,= LF,
 
Wow! 5641km is really imp= ressing! Congrats!!
 
Is there such an activity= planned for the "west-stations" as well? We could do the same!<= /font>
 
I've never been slower th= an DFCW-10 on LF. Would be interesting :-)
 
73, Stefan/DK7FC

Von: owner-rsgb_lf_group@blackshee= p.org im Auftrag von Mike Dennison
Gesendet: So 04.04.2010 12:09
An: rsgb_lf_group@blacksheep.org
Betreff: LF: Activity 3 Mar 2010

An excellent day's activity on 137kHz yesterday with= 5 countries
received, the furthest easterly station received here and a QSO with
a new country.

In the morining, OE5ODL and DJ6GT were received.

During the UA tests, five stations were logged (see the attached
screen grab - Argo set to QRSS30 and centred on 137.778kHz).
The picture shows (from the top) UA0AET (5641km from me); RA3YO;
RN3AGC; UA4WPF; and EW6GB who was first received as early as 1700UTC.

After the formal test I exchanged 'O' reports with EW6GB at 1902km,
using QRSS10.

Well done to all concerned.

Mike, G3XDV
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

--_000_BF4A524700075746A6467658DFC7102C19A043E518ICTSSEXC2CAlu_--