Return-Path: Received: from mtain-ma01.r1000.mx.aol.com (mtain-ma01.r1000.mx.aol.com [172.29.96.9]) by air-mc02.mail.aol.com (v128.1) with ESMTP id MAILINMC022-a8d44bb9ff3f3c6; Mon, 05 Apr 2010 11:18:23 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-ma01.r1000.mx.aol.com (Internet Inbound) with ESMTP id DB66138000106; Mon, 5 Apr 2010 11:18:20 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Nyo38-0001yr-9g for rs_out_1@blacksheep.org; Mon, 05 Apr 2010 16:17:14 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Nyo37-0001yi-AX for rsgb_lf_group@blacksheep.org; Mon, 05 Apr 2010 16:17:13 +0100 Received: from cavuit01.kulnet.kuleuven.be ([134.58.240.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Nyo34-0005MQ-SE for rsgb_lf_group@blacksheep.org; Mon, 05 Apr 2010 16:17:13 +0100 Received: from smtps01.kuleuven.be (smtpshost01.kulnet.kuleuven.be [134.58.240.74]) by cavuit01.kulnet.kuleuven.be (Postfix) with ESMTP id 1A0B87B8048 for ; Mon, 5 Apr 2010 17:17:03 +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 E7FBA31E702 for ; Mon, 5 Apr 2010 17:17:02 +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 17:17:02 +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 17:17:02 +0200 Thread-Topic: RE: RE: RE: W1VLF 9 Khz Antenna update Putting inductance near the top. Thread-Index: AcrUxOYaSLNeYAGjT8KxvcNwblXcCQADLUbG Message-ID: References: , In-Reply-To: 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: RE: W1VLF 9 Khz Antenna update Putting inductance near the top. Content-Type: multipart/alternative; boundary="_000_BF4A524700075746A6467658DFC7102C19A043E516ICTSSEXC2CAlu_" 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: 3039ac1d60094bb9ff3c7a93 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --_000_BF4A524700075746A6467658DFC7102C19A043E516ICTSSEXC2CAlu_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Paul, if you put the coil at the top of a tower try to keep it as far as possibl= e from metal object as these can lower the Q. About the "working principle": a coil at the top of the vertical section will reduce the "current deflati= on" through the vertical section. The result is a higher average current= and thus a larger radiation resistance (or effective height if you prefer= that). The stange thing is that the improvement measured is (much) more than the= theoretical value if the antenna is surrounded by trees, buidings etc... In my 136kHz antenna setup the theoretical gain was about 1dB, while 5dB= was measured by PA0SE. I did construct a light weight coil that was just "hanging" at the top of= the vertical section, far away from any lossy objects. So I am not sure= what the effect will be if the coil is close to metel or wet wood. I guess the only way to find out is to try ... 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: maandag 5 april 2010 16:31 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: RE: RE: RE: W1VLF 9 Khz Antenna update Putting inductance= near the top. Rik Thanks for that reply. Very interesting material. I am going to attempt to put a coil at the top about 1 meter below where= the top hat begins. The value will be approx 1/2 of the overall value needed to resonate. The QTH is hardly the best site for LF VLF so perhaps it will help. Later I take pictures of my QTH and put them on the web, someone suggested= that a while ago. This would give others the ability to "Critique" the antenna. I still do not really understand the premise by which coil works to incre= ase gain. PauLC W1VLF -----Original Message----- From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@black= sheep.org]On Behalf Of Rik Strobbe Sent: Sunday, April 04, 2010 5:40 PM To: rsgb_lf_group@blacksheep.org Subject: 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_BF4A524700075746A6467658DFC7102C19A043E516ICTSSEXC2CAlu_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Paul,<= /font>
 
if you put the coil = ;at the top of a tower try to keep it as far as possible from metal= object as these can lower the Q.
 
About the "working= principle":
a coil at the top of the= vertical section will reduce the "current deflation" throu= gh the vertical section. The result is a higher average current and thus= a larger radiation resistance (or effective height if you prefer that).
The stange thing is that= the improvement measured is (much) more than the theoretical value if the= antenna is surrounded by trees, buidings etc...
In my 136kHz antenna set= up the theoretical gain was about 1dB, while 5dB was measured by PA0SE.
I did construct a light= weight coil that was just "hanging" at the top of the vertical= section, far away from any lossy objects. So I am not sure what the effec= t will be if the coil is close to metel or wet wood.
I guess the only way to= find out is to try ...
 
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: maandag 5 april 2010 16:31
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: LF: RE: RE: RE: W1VLF 9 Khz Antenna update Putting induc= tance near the top.

Rik
 
Thanks for that reply. Very interesting material. 
I am going to attempt to put a coil at the top about 1 meter below where= the top hat begins.
 
The value will be approx 1/2 of the overall value needed to resonate.
The QTH is hardly the best site for LF VLF so perhaps it will help.
 
Later I take pictures of my QTH and put them on the web, someone suggeste= d that a while ago.
This would give others the ability to "Critique" the antenna.
 
I still do not really understand the  premise by which coil works to= increase gain.
 
PauLC
W1VLF
-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_grou= p@blacksheep.org]On Behalf Of Rik Strobbe
Sent: Sunday, April 04, 2010 5:40 PM
To: rsgb_lf_group@blacksheep.org
Subject: 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_BF4A524700075746A6467658DFC7102C19A043E516ICTSSEXC2CAlu_--