Return-Path: Received: from mtain-mc03.r1000.mx.aol.com (mtain-mc03.r1000.mx.aol.com [172.29.96.75]) by air-dc06.mail.aol.com (v129.4) with ESMTP id MAILINDC062-862a4d2ccf6552; Tue, 11 Jan 2011 16:45:09 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mc03.r1000.mx.aol.com (Internet Inbound) with ESMTP id D600B38000111; Tue, 11 Jan 2011 16:45:07 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Pcm0Q-0003ze-Pf for rs_out_1@blacksheep.org; Tue, 11 Jan 2011 21:43:54 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Pcm0P-0003zV-E2 for rsgb_lf_group@blacksheep.org; Tue, 11 Jan 2011 21:43:53 +0000 Received: from mail-wy0-f171.google.com ([74.125.82.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Pcm0M-0002gD-OG for rsgb_lf_group@blacksheep.org; Tue, 11 Jan 2011 21:43:53 +0000 Received: by wyb38 with SMTP id 38so20821874wyb.16 for ; Tue, 11 Jan 2011 13:43:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:subject:references:from :content-type:x-mailer:in-reply-to:message-id:date:to :content-transfer-encoding:mime-version; bh=LNUm/7OcXfwDER4d3/80mcaIt7dk/N9ymQZGd1R6bQQ=; b=cRExkiy5ZRWwkH13zKZlJrkcUi65HmzJoE+wLrWW4ccj44IcduH/iIUeOv9zXNFKeJ ZJwGy/hDYBJI9qU2qgEF6MJzWGVz+ZZXVXfPtGeFOTxfMIcX7ISuFxSmCBcj6lbzivpT AjmyFSwHXKtPTzf3raMxdnMW7ZSLJx0kiifvQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; b=jiMebu0yz1qCsk8xfBl6JVv+3wPxH5O2P4gdbpXYqx4/xTCVSoHp3tzJnCUKH3ES/S UpBmnlEQXdEJpgfOYeFmxCWhXhA7GhnGY1+92T31O4h0WbvahRxUc5VtAe2F9js7cP/k iZCNU9qk/IInelz47sQBzW9gN1U8RAznyzY/Y= Received: by 10.227.207.133 with SMTP id fy5mr99544wbb.222.1294782224605; Tue, 11 Jan 2011 13:43:44 -0800 (PST) Received: from [192.168.1.104] (cpc3-cmbg14-0-0-cust445.5-4.cable.virginmedia.com [213.106.93.190]) by mx.google.com with ESMTPS id x3sm14997320wes.22.2011.01.11.13.43.41 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 11 Jan 2011 13:43:43 -0800 (PST) References: <95F786F2-4722-44F1-B787-879A560FF239@gmail.com> From: Roger Lapthorn X-Mailer: iPod Mail (8C148) In-Reply-To: Message-Id: <6C13E6E6-19D0-4162-A2D0-E6D5F5B7DD88@gmail.com> Date: Tue, 11 Jan 2011 21:44:47 +0000 To: "rsgb_lf_group@blacksheep.org" Mime-Version: 1.0 (iPod Mail 8C148) DomainKey-Status: good (testing) X-Spam-Score: 0.1 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,HTML_TAG_EXIST_TBODY=0.126 Subject: Re: LF: Re: Increased ERP on 137.5kHz - WSPR reports please Content-Type: multipart/alternative; boundary=Apple-Mail-7-794992153 Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.2 required=5.0 tests=HTML_FONTCOLOR_UNSAFE, HTML_MESSAGE,HTML_TAG_EXISTS_TBODY,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-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m025.2 ; domain : gmail.com DKIM : fail x-aol-sid: 3039ac1d604b4d2ccf637aae X-AOL-IP: 195.171.43.25 --Apple-Mail-7-794992153 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii 5w 73s Roger=20 Sent from my iPod Touch 4g On 11 Jan 2011, at 21:17, Rik Strobbe wrote: > Roger, > =20 > what power do you need to get 0.18A into the antenna ? > =20 > 73, Rik > =20 > Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.= org] namens Roger Lapthorn [rogerlapthorn@gmail.com] > Verzonden: dinsdag 11 januari 2011 22:05 > Aan: rsgb_lf_group@blacksheep.org > Onderwerp: Re: LF: Re: Increased ERP on 137.5kHz - WSPR reports please >=20 > Yes Rik, the ferrite rod ATU is just sitting on the bedroom table. I use= d a similar arrangement quite successfully on 500kHz but this, plus the ve= ry short vertical, are not good enough on 136kHz. At QRP levels I think a= ferrite rod is OK in an ATU but I need more wire in the air. >=20 > 73s > Roger G3XBM >=20 > Sent from my iPod Touch 4g >=20 > On 11 Jan 2011, at 20:39, Rik Strobbe wrot= e: >=20 >> Hello Roger, >> =20 >> "coil on the bedroom table" : do you have the loading coil indoors ? >> It might be worth trying to place the coil outside to reduce losses. >> =20 >> 73, Rik ON7YD=20 >> =20 >> Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep= .org] namens Roger Lapthorn [rogerlapthorn@gmail.com] >> Verzonden: dinsdag 11 januari 2011 20:13 >> Aan: rsgb_lf_group@blacksheep.org >> Onderwerp: Re: LF: Re: Increased ERP on 137.5kHz - WSPR reports please >>=20 >> This agrees well with my calculation Rik. As I said, the issue is where= the power is going: with such a short vertical section (5m long and assum= ed Heff of 3m) without any real top loading most of the energy is being di= ssipated in the coil on the bedroom table. >>=20 >> Currently TXing into the earth electrodes and G6ALB is getting me at -1= 8dB S/N at 3km. I've a lot of work to do... >>=20 >> 73s >> Roger g3XBM >>=20 >> On 11 January 2011 19:03, Rik Strobbe wro= te: >> Hello Roger, >> =20 >> 3m Heff @ 2200m --> Rrad =3D 1580*(3/2200)^2 =3D +/- 0.003 Ohm >> radiated power =3D 0.18^2*0.003 =3D +/- 100uW >> Gain of a short vertical =3D 1.83 --> ERP =3D +/- 180uW >> But "greenery loss" can be up to 6dB (or even more), so instead of 180u= W it could less than 50uW as well. >> =20 >> I have wspr running, being very very optimistic ;-) >> =20 >> 73, Rik ON7YD - OR7T >> =20 >> Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep= .org] namens Roger Lapthorn [rogerlapthorn@gmail.com] >> =20 >> =20 >> =20 >> =20 >> =20 >>=20 >> Verzonden: dinsdag 11 januari 2011 19:43 >> Aan: rsgb_lf_group@blacksheep.org >> Onderwerp: Re: LF: Re: Increased ERP on 137.5kHz - WSPR reports please >>=20 >> 0.18A and an assumed Heffective of 3m Andy. >>=20 >> 73s >> Roger G3XBM >>=20 >> On 11 January 2011 18:39, Andy Talbot wrote: >> What antenna current are you getting? >> - OR - >> What is the total resonant input resistance of the vertical + ground sy= stem (before any matching network) .and the RF power being delivered into= this, >> =20 >> Either of these will allow a reasonable estimate of ERP >> =20 >> Andy >> www.g4jnt.com >> =20 >>=20 >>=20 >> =20 >> On 11 January 2011 18:26, Roger Lapthorn wrot= e: >> So much for the theory then.... >>=20 >> The signal level at G6ALB in the next village (3km although WSPR shows= it as 0km) is some 10dB down on my loop antenna. Not sure if I got my sum= s wrong or there is some unexplained loss. The RX system at G6ALB is uncha= nged. >>=20 >> 73s >> Roger G3XBM >>=20 >> On 11 January 2011 17:32, Roger Lapthorn wrot= e: >> Dear All, >>=20 >> Today I rigged up and matched a simple, small, Marconi vertical on 136k= Hz instead of the vertical loop. Based on measurements of antenna current= and some reasonable assumptions of effective height, I now believe I have= around 200uW ERP on the band - heck this is high power for me! >>=20 >> From now until late this evening I will run the WSPR beacon (136kHz USB= dial) in the hope that a few more people will be able to copy the QRPp si= gnal. Please have a go and let me have any reports. >>=20 >> 73s and good luck >>=20 >> Roger G3XBM >>=20 >> --=20 >> g3xbm-qrp.blogspot.com/ >> www.g3xbm.co.uk >> www.youtube.com/user/g3xbm >> G3XBM GQRP 1678 ISWL G11088 >>=20 >>=20 >>=20 >> --=20 >> g3xbm-qrp.blogspot.com/ >> www.g3xbm.co.uk >> www.youtube.com/user/g3xbm >> G3XBM GQRP 1678 ISWL G11088 >> =20 >> =20 >> =20 >> =20 >> =20 >>=20 >>=20 >>=20 >>=20 >> --=20 >> g3xbm-qrp.blogspot.com/ >> www.g3xbm.co.uk >> www.youtube.com/user/g3xbm >> G3XBM GQRP 1678 ISWL G11088 >>=20 >>=20 >>=20 >> --=20 >> g3xbm-qrp.blogspot.com/ >> www.g3xbm.co.uk >> www.youtube.com/user/g3xbm >> G3XBM GQRP 1678 ISWL G11088 >=20 --Apple-Mail-7-794992153 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
5w

73s
=
Roger 

Sent from my iPod Touch 4g

On 11 Jan= 2011, at 21:17, Rik Strobbe <Rik.Strobbe@fys.kuleuven.be> wrote:

<= blockquote type=3D"cite">
Roger,
 
what power do you need to get 0.18A= into the antenna ?
 
73, Rik
 
Van: owner-rsgb_lf_group@blacksheep.= org [owner-rsgb_= lf_group@blacksheep.org] namens Roger Lapthorn [rogerlapthorn@gmail.com]
Verzonden: dinsdag 11 januari 2011 22:05
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: Re: Increased ERP on 137.5kHz - WSPR reports ple= ase

Yes Rik, the ferrite rod ATU is just sitting on the bedroom table. I= used a similar arrangement quite successfully on 500kHz but this, plus th= e very short vertical, are not good enough on 136kHz. At QRP levels I thin= k a ferrite rod is OK in an ATU but I need more wire in the air.

73s
Roger G3XBM

Sent from my iPod Touch 4g

On 11 Jan 2011, at 20:39, Rik Strobbe <Rik.Strobbe@= fys.kuleuven.be> wrote:

Hello Roger,
 
"coil on the bedroom table" : do you= have the loading coil indoors ?
It might be worth trying to place th= e coil outside to reduce losses.
 
73, Rik  ON7YD 
 
Van: owner-rsgb_lf_group@= blacksheep.org [owner-rsgb_lf_gr= oup@blacksheep.org] namens Roger Lapthorn [rogerlaptho= rn@gmail.com]
Verzonden: dinsdag 11 januari 2011 20:13
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: Re: Increased ERP on 137.5kHz - WSPR reports ple= ase

This agrees well with my calculation Rik. As I said, the issue is whe= re the power is going: with such a short vertical section (5m long and ass= umed Heff of 3m) without any real top loading most of the energy is being= dissipated in the coil on the bedroom table.

Currently TXing into the earth electrodes and G6ALB is getting me at -18dB= S/N at 3km. I've a lot of work to do...

73s
Roger g3XBM

On 11 January 2011 19:= 03, Rik Strobbe <<= a href=3D"mailto:Rik.Strobbe@fys.kuleuven.be">Rik.Strobbe@fys.kuleuven.be> wrote:
Hello Roger,
 
3m Heff @ 2200m --> Rrad =3D 1580= *(3/2200)^2 =3D +/- 0.003 Ohm
radiated power =3D 0.18^2*0.003 =3D= +/- 100uW
Gain of a short vertical =3D 1.83 --= > ERP =3D +/- 180uW
But "greenery loss" can be up to 6dB= (or even more), so instead of 180uW it could less than 50u= W as well.
 
I have wspr running, being very very= optimistic ;-)
 
73, Rik  ON7YD - OR7T
 
Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] nam= ens Roger Lapthorn [roge= rlapthorn@gmail.com]
   
 
       
 
 

Verzonden: dinsdag 11 januari 2011 19:43
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: Re: Increased ERP on 137.5kHz - WSPR reports ple= ase

0.18A and an assumed Heffective of 3m Andy.

73s
Roger G3XBM

On 11 January 2011 18:= 39, Andy Talbot <a= ndy.g4jnt@gmail.com> wrote:
What antenna current are you getting?
 - OR -
What is the total resonant input resistance of the vertical + ground= system (before any matching network) .and the RF power being delivered in= to this,
 
Either of  these will allow a reasonable estimate of ERP
 
Andy
 


 
On 11 January 2011 18:26, Roger Lapthorn <rogerlaptho= rn@gmail.com> wrote:
So much for the theory then....

The signal level at G6ALB in the next village (3km although WSPR shows it= as 0km) is some 10dB down on my loop antenna. Not sure if I got my sums wrong or there= is some unexplained loss. The RX system at G6ALB is unchanged.

73s
Roger G3XBM

On 11 January 2011 17:= 32, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
Dear All,

Today I rigged up and matched a simple, small, Marconi vertical on 136kHz= instead of the vertical loop. Based on measurements of antenna current an= d some reasonable assumptions of effective height, I now believe I have ar= ound 200uW ERP on the band - heck this is high power for me!

>From now until late this evening I will run the WSPR beacon (136kHz USB di= al) in the hope that a few more people will be able to copy the QRPp signa= l. Please have a go and let me have any reports.

73s and good luck

Roger G3XBM

--
g3xbm-qrp.blogspot.com/
ww= w.g3xbm.co.uk
www.youtube.com/user/g3xbm
G3XBM   GQ= RP 1678    ISWL G11088



--
g3xbm-qrp.blogspot.com/
ww= w.g3xbm.co.uk
www.youtube.com/user/g3xbm
G3XBM   GQ= RP 1678    ISWL G11088
   
 
       
 
 
<= /a>




--
g3xbm-qrp.blogspot.com/
www= .g3xbm.co.uk
www.youtube.com/user/g3xbm
G3XBM   GQR= P 1678    ISWL G11088



--
g3xbm-qrp.blogspot.com/
www= .g3xbm.co.uk
www.youtube.com/user/g3xbm
G3XBM   GQR= P 1678    ISWL G11088
   
 
       
 
 
=3D --Apple-Mail-7-794992153--