Return-Path: Received: from mtain-dj04.r1000.mx.aol.com (mtain-dj04.r1000.mail.aol.com [172.19.187.140]) by air-mc08.mail.aol.com (v129.4) with ESMTP id MAILINMC083-a98d4c1e34a63a1; Sun, 20 Jun 2010 11:32:54 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dj04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 8E59B38000190; Sun, 20 Jun 2010 11:32:49 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OQMUr-0000TR-Uv for rs_out_1@blacksheep.org; Sun, 20 Jun 2010 16:31:45 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OQMUr-0000TI-AX for rsgb_lf_group@blacksheep.org; Sun, 20 Jun 2010 16:31:45 +0100 Received: from mail-ww0-f43.google.com ([74.125.82.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OQMUp-0000vB-D5 for rsgb_lf_group@blacksheep.org; Sun, 20 Jun 2010 16:31:45 +0100 Received: by wwe15 with SMTP id 15so490249wwe.16 for ; Sun, 20 Jun 2010 08:31:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:content-type; bh=VKMoTSithojBJqk99gcBJjF/36rlUnlrhwJ5jpl3lKk=; b=jSxFoD4lasQgzSZv6wbm0drJ6TiokHcpxDCDpUZpFd64ae2+gkAA+bse9DThVIGWpU 5crxYWEAo5qDnJr3gt/E1G+0qNxpDPvMNBGhUTai7yWkMlQqMvlOYfCCrrYpZyg7gLqT fRUmwZdB3l4GcVk/QdKNfS5Gvho2qcUqzQ5nI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=V2C/h+yii1nwsoRLfNBOmltpm+bFrqBVxHelAwWBmTWCwwdvHL+ay+QIUuWlkqdtcx uMHtA8OzkcxIxjP69hn5mGdK5AEX6BHzu6A6V8hsaBk2ldjF4IeLrmmmD8ROARClCN72 Hntkj7VeKTXObubjpwsSNoW/UrZyNBgm2xDxU= MIME-Version: 1.0 Received: by 10.216.172.83 with SMTP id s61mr1908503wel.1.1277047896118; Sun, 20 Jun 2010 08:31:36 -0700 (PDT) Received: by 10.216.175.12 with HTTP; Sun, 20 Jun 2010 08:31:36 -0700 (PDT) In-Reply-To: <002401cb1076$f4620140$0401a8c0@xphd97xgq27nyf> References: <002401cb1076$f4620140$0401a8c0@xphd97xgq27nyf> Date: Sun, 20 Jun 2010 16:31:36 +0100 X-Google-Sender-Auth: nDjUwhj-kpwKztjCX1RwKXxkTeg Message-ID: From: Gary - G4WGT To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: 137.500 kHz ROS beacon Content-Type: multipart/alternative; boundary=0016367b632035987d048977e229 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=HTML_MESSAGE 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-m224.2 ; domain : gmail.com DKIM : fail x-aol-sid: 3039cdbc9d084c1e34a13a07 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0016367b632035987d048977e229 Content-Type: text/plain; charset=ISO-8859-1 Hi Mal, Thank you for your report & comments. The mail you replied to gives all the details of equipment in use for the test beacon. I would like to be able to have a QSO using morse but I have to admit to a complete loss of confidence as I have not used the mode for 25 years which was one year after I passed the test in 1984. Looking back, letting it go was a silly thing to do. I do enjoy testing out these "weak signal" modes & in the report I received from Michel F5WK last night he wrote that he could not hear the signal or even see it on SpecLab but he got a complete decode. So as a weak signal communication mode it works. Just to elaborate on the antenna, it is a 12 metre base loaded vertical with a small elevated inductor of 500uH at about 9 metres & a 1 x 3 metre capacity top with a 120uH spiral inductor. In my small garden I have no space to go outwards only upwards. 73, Gary - G4WGT. On 20 June 2010 13:48, mal hamilton wrote: > Gary > If that was you last nite on 137.5 kcs you were strong enough for cw or > qrs3 no need to struggle with decodes from elswhere. > also I had a qso with G3XIZ this morning on 137.0 kcs and got 599, he was > 569. > Not sure what antenna u were using but it was putting out a fair signal to > this qth. Your radiators are probably acting as an antenna above earth. > > de mal/g3kev > > > ----- Original Message ----- > *From:* Gary - G4WGT > *To:* LF Group (RSGB) > *Sent:* Sunday, June 20, 2010 12:07 PM > *Subject:* LF: 137.500 kHz ROS beacon > > > Hi LF, > > Having successfully bench & on-air tested a x2 harmonic amplifier method of > driving my G0MRF Class D LF transmitter, I ran a beacon last night (Saturday > 19th) on 137.500 kHz. > > An extract from my previous e-mail description is shown at the end. > > Using the equipment & method described below, the ERP from my 12 metre > vertical antenna was around 150mW. The mode was ROS MF-1, 100 Hz bandwidth. > > I received the following report from Michel, F5WK in JN18HP, a distance of > 410 miles (661 kilometres) in daylight. > > >> Not even a faint trace on a QRSS3 spectrum but: > > >> RX1: 19:23 @ 5.9 Hz: 9 -37 dB > >> RX1: 19:28 @ 5.4 Hz: O4WGT -34 dB > >> RX1: 19:33 @ 5.4 Hz: G4WGT -31 dB > > The x2 harmonic low level amplifier is a simple way of driving a Class D > type of transmitter which employs a divide by 2 drive chain. My limitation > with multi tone drive is that my DDS VFO will only produce 2 frequencies ie. > the main frequency & a CW/Rx offset which has previously limited me to 2 > tones as with RTTY & DFCW modes. > > Please bear in mind that it will not be suitable for modes like PSK were > tones are transmitted simultaneously. > > At the moment the 2 small PCB's are precariously lying on the desk, when I > have cased them I will publish the circuit & pictures. > > 73 > > Gary - G4WGT. > > *********************************************** > > > After a few days experimenting & bench testing a method of driving my > G0MRF Class D Tx on the 137.000 kHz band from my linear transverter I > finally > constructed a harmonic amplifier producing a 274.000 kHz signal from > 137.000 > kHz input. An "on-air" trial was conducted resulting in a QSO with > Graham G0NBD on 137.000 kHz using ROS data mode software. > > My thanks to Graham for his ideas & tests. > > The mode used was ROS MF-7. The equipment used for the QSO was as > follows. Kenwood TS-440 to my LF-MF linear transverter producing the > 137.000 kHz signal, followed by a tuned harmonic circuit & buffer > amplifier whose output was 274.000 kHz therefore at x2 drive for the > Class > D Tx. The x2 signal is then divided by the Tx driver chain in the > normal way to provide 137.000 kHz to the PA. > > This method should also work well using WSPR & other similar modes. > > > ********************************************* > > --0016367b632035987d048977e229 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Mal,

Thank you for your report & comments. The= mail you replied to gives all the details of equipment in use for the tes= t beacon.

I would like to be able to have a QSO= using morse but I have to admit to a complete loss of confidence as I hav= e not used the mode for 25 years which was one year after I passed the tes= t in 1984. Looking back, letting it go was a silly thing to do.

I do enjoy testing out these "weak signal"= modes & in the report I received from Michel F5WK last night he wrote= that he could not hear the signal or even see it on SpecLab but he got a= complete decode. So as a weak signal communication mode it works.

Just to elaborate on the antenna, it is a 12 metre bas= e loaded vertical with a small elevated inductor of 500uH at about 9 metre= s & a 1 x 3 metre capacity top with a 120uH spiral inductor. In my sma= ll garden I have no space to go outwards only upwards.

73,

Gary - G4WGT.

On 20 June 2010 13:48, mal hamilton <g3kevmal@talktalk.net&= gt; wrote:
Gary
If that was you last nite on=A0 137.5= kcs you=20 were strong enough for cw or qrs3=A0no need to struggle with decodes from= =20 elswhere.
also I had a qso with G3XIZ this morn= ing on 137.0=20 kcs and got 599, he was 569.
Not sure what antenna u were using=A0= but it was=20 putting out a fair signal to this qth. Your radiators are probably acting= as an=20 antenna above earth.
=A0
de mal/g3kev
=A0
----- Original Message -----
From:=20 Gary -=20 G4WGT
Sent: Sunday, June 20, 2010 12:07= =20 PM
Subject: LF: 137.500 kHz ROS beaco= n

    Hi LF,
Having successfully bench & on-air tested a x2 harmonic amplifi= er=20 method of driving my G0MRF Class D LF transmitter, I ran a beacon last= night=20 (Saturday 19th) on 137.500 kHz.

An extract from my previous e-mail description is shown at the end.=

Using the equipment & method described below, the ERP from my= 12=20 metre vertical antenna was around 150mW. The mode was ROS MF-1, 100 Hz= =20 bandwidth.

I received the following report from Michel, F5WK in JN18HP, a dist= ance=20 of 410 miles (661 kilometres) in daylight.

>> Not even a faint trace on a QRSS3 spectrum but:

>= ;>=20 RX1: 19:23 @ 5.9 Hz: 9 <STOP> -37 dB
>> RX1: 19:28 @ 5.4= Hz:=20 O4WGT <STOP> -34 dB
>> RX1: 19:33 @ 5.4 Hz: G4WGT <STO= P>=20 -31 dB

The x2 harmonic low level amplifier is a simple way of driving a Cl= ass D=20 type of transmitter which employs a divide by 2 drive chain. My limitati= on=20 with multi tone drive is that my DDS VFO will only produce 2 frequencies= ie.=20 the main frequency & a CW/Rx offset which has previously limited me= to 2=20 tones as with RTTY & DFCW modes.

Please bear in mind that it will not be suitable for modes like PSK= were=20 tones are transmitted simultaneously.

At the moment the 2 small PCB's are precariously lying on the= desk, when=20 I have cased them I will publish the circuit & pictures.

73

Gary - G4WGT.
    ***********************************************
    After a few days experimenting & bench testing a method of drivi= ng=20 my
    G0MRF Class D Tx on the 137.000 kHz band from my linear transver= ter I=20 finally
    constructed a harmonic amplifier producing a 274.000 kHz si= gnal=20 from 137.000
    kHz input. An "on-air" trial was conducted= resulting in a=20 QSO with
    Graham G0NBD on 137.000 kHz using ROS data mode=20 software.
    =A0
    My thanks to Graham for his ideas &=20 tests.
    =A0
    The mode used was ROS MF-7. The equipment used for th= e=20 QSO was as
    follows. Kenwood TS-440 to my LF-MF linear transverter= =20 producing the
    137.000 kHz signal, followed by a tuned harmonic circ= uit=20 & buffer
    amplifier whose output was 274.000 kHz therefore at x2= drive=20 for the Class
    D Tx. The x2 signal is then divided by the Tx driver= chain=20 in the
    normal way to provide 137.000 kHz to the PA.
    =A0
    This= =20 method should also work well using WSPR & other similar modes.
      *********************************************

--0016367b632035987d048977e229--