Return-Path: Received: from mtain-dk06.r1000.mx.aol.com (mtain-dk06.r1000.mx.aol.com [172.29.180.10]) by air-db08.mail.aol.com (v129.4) with ESMTP id MAILINDB081-85f44d55baed3f; Fri, 11 Feb 2011 17:40:46 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk06.r1000.mx.aol.com (Internet Inbound) with ESMTP id BAECC380000B8; Fri, 11 Feb 2011 17:40:43 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Po1eI-0005Br-FM for rs_out_1@blacksheep.org; Fri, 11 Feb 2011 22:39:34 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Po1eH-0005Bi-Ju for rsgb_lf_group@blacksheep.org; Fri, 11 Feb 2011 22:39:33 +0000 Received: from nm11.bullet.mail.ukl.yahoo.com ([217.146.183.185]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1Po1eH-0003oZ-H1 for rsgb_lf_group@blacksheep.org; Fri, 11 Feb 2011 22:39:33 +0000 Received: from [217.146.183.181] by nm11.bullet.mail.ukl.yahoo.com with NNFMP; 11 Feb 2011 22:39:27 -0000 Received: from [217.146.183.60] by tm12.bullet.mail.ukl.yahoo.com with NNFMP; 11 Feb 2011 22:39:27 -0000 Received: from [127.0.0.1] by omp1029.mail.ukl.yahoo.com with NNFMP; 11 Feb 2011 22:39:27 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 834814.96615.bm@omp1029.mail.ukl.yahoo.com Received: (qmail 44950 invoked by uid 60001); 11 Feb 2011 22:39:27 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s1024; t=1297463967; bh=jBpS0Y4ohmWEeeLsUOQzuVT03UUFDnKrOX3FeMaMQbg=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=SA4Oo1u5z4HC1I1ziJCxSXOGarVzJRua3gnXemBzyrRDL503AwqM6s9E+2lHj2Rlw64pqHCH+tY6yL8VZt0wxxt3dxNZ/HC9ln0VaXyU9SXAKUMDKwLrim81MP8Sv2ZvLa860ECa08nTVKx9hW5rV7ThUvj1COtLGxMrf+ytY6Y= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.uk; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=QF8AikokOlyWijSlt+bUEDsJcfxl9qTPom+kUla9STS4I3bghVUTet7/PDLt8t8Zxsf+y1vb8ns8arj6weNJ0QO6Fh+dWJqVOmRKkc64sI5jo8yA+amiQG89kj3XJF7SWvbti5+++m52ct8ar2ADFQeAPzkMMVDOOK08WL/OTTs=; Message-ID: <690897.31788.qm@web28511.mail.ukl.yahoo.com> X-YMail-OSG: grKdcccVM1kR.kkLiAkR_3vjRdXjhONvLnP92WNoZmaLT.b PkGqmYsHdjBeezfQzDHBfu61NznfYxUzO_Z5vcDuGfZUqmnDebRhGRzQSkr. rywW.r42aS6V9lsf.UfUeDZ6AtOhEAne9DAruP6tAlzeZwaZa3dJDIhZHVkA dVdbh.5Y8RVxbOuaslq.cDEQRcKwTLCK4JaWVls2KzMI9JznLs8fX8iiG_cj cRC.2M9a9OnTe0sjSwNSfcRyzvlODANw5IWBun1ejxZcly9ScEF8gPfpgxQB 1NWK08KoCwls- Received: from [81.97.191.183] by web28511.mail.ukl.yahoo.com via HTTP; Fri, 11 Feb 2011 22:39:27 GMT X-Mailer: YahooMailRC/555 YahooMailWebService/0.8.108.291010 References: <988315.45122.qm@web28515.mail.ukl.yahoo.com> <4D5436DE.3040602@iup.uni-heidelberg.de> <673772.16865.qm@web28515.mail.ukl.yahoo.com> <004c01cbca06$f1b88f50$0401a8c0@xphd97xgq27nyf> Date: Fri, 11 Feb 2011 22:39:27 +0000 (GMT) From: Chris Osborn To: rsgb_lf_group@blacksheep.org In-Reply-To: <004c01cbca06$f1b88f50$0401a8c0@xphd97xgq27nyf> MIME-Version: 1.0 DomainKey-Status: good (testing) Subject: Re: LF: VLF Transmissions - G3XIZ - 12th / 13th February Content-Type: multipart/alternative; boundary="0-2056673091-1297463967=:31788" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=HTML_50_60,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY 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-d310.2 ; domain : yahoo.co.uk DKIM : pass x-aol-sid: 3039ac1db40a4d55baeb37e6 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0-2056673091-1297463967=:31788 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Mal,=20 I calculate the PA including the mains transformer is about 70% efficient. The push-pull FET's are wired to the 10 - 0 - 10V windings and the output= =20 tappings are at 0 and 240 volts. It has a laminated iron core. The measured secondary voltage is about 350 volts rms so I dare not push= the=20 output power any higher. I'm hoping that with a more efficient loading coil the secondary voltage= will=20 reduce and I can then push more power, hence current into the aerial. I initially tried a LOPT but found the power output very limited. Maybe I was doing something wrong ! 73 Chris G3XIZ ________________________________ From: mal hamilton To: rsgb_lf_group@blacksheep.org Sent: Fri, 11 February, 2011 16:15:43 Subject: Re: LF: VLF Transmissions - G3XIZ - 12th / 13th February =20 Chris How efficient is ur mains transformer at 9 Khz, what sort of core, ferrit= e or=20 laminated iron I assume from what u say you couple your 5 ohm impedence PA to this trans= former=20 PRIM and output from the SEC to the antenna loading coil. Is the PRIM nor= mal=20 250v and what is the sec voltage. or do u use a 6v winding. etc=20 I have a selection of mains transformers which I could ck out. Have u tried instead a LOPT=20 de mal/g3kev =20 ----- Original Message -----=20 >From: Chris Osborn=20 >To: rsgb_lf_group@blacksheep.org=20 >Sent: Thursday, February 10, 2011 7:23 PM >Subject: Re: LF: VLF Transmissions - G3XIZ - 12th / 13th February > > >Mal, Roger, Stefan and group > >Thanks for the good wishes. >It will all depend on weather conditions as to whether I can fly the= balloons=20 >but I shall keep you posted via the reflector. > >I can try longer QRSS periods but begrudge the long wasted 'off' times= =20 >especially if I'm having trouble keeping the balloons aloft. >A compromise would be for me to manually cut the carrier for 5-10 minu= te=20 >periods. > >The transmitter feeds the loading coil and aerial via a large step up= (mains)=20 >transformer. >The TX/ transformer will push its RF power into 2000 - 3000 ohms which= is an=20 >approximation of the aerial circuit resistance when resonant.. >I tried using a 50 ohms TX output and link coupling to the loading coi= l but=20 >without success. > >The aerial current should be as before about 0.15 - 0.2 A > >73 >Chris G3XIZ > > > > > > ________________________________ From: Stefan Sch=E4fer >To: rsgb_lf_group@blacksheep.org >Sent: Thu, 10 February, 2011 19:05:02 >Subject: Re: LF: VLF Transmissions - G3XIZ - 12th / 13th February > >Hi Chris,=20 > >I think DFCW-600 or even 2400 is a good compromise between a constant= carrier =20 >and some ID but 60 is probably to fast. Jim received you in less than 2= mHz if =20 >i remember correctly. QRSS60 is to fast for that. Looking forward to your= =20 >results :-) > >73, Stefan > >Am 10.02.2011 18:52, schrieb Roger Lapthorn:=20 >Hi Chris, >> >>Very good luck. I'll be looking for you and hoping for success this= time.=20 >> >>An email direct and to this group saying when TX starts/ends would= be=20 >>helpful. Don't suppose you can send QRSS60 or similar to help with= ID? Have=20 >>passed the word on to Nick G4IKZ as he is closer to you than me and= not=20 >>sure he subscribes to this list. >> >>73s >>Roger G3XBM >> >> >> >>On 10 February 2011 14:42, Chris Osborn wrote: >> >>LF, >>>=20 >>>I have had permission to transmit on VLF this coming weekend: 12th = and=20 >>>13th February. >>>Weather permitting I shall try again with my balloon-launched aerial,= =20 >>>hopefully about 50m vertical. >>>=20 >>>The frequency will be=20 >>>=20 >>>8.976 66 kHz (i.e. 10.000 MHz / 1114) and is derived from an ov= en=20 >>>controlled xtal oscillator. >>>Hopefully the frequency will be more stable than last time. >>>If this frequency proves unsuitable I can transmit on 10.000 MHZ / = 1112 .=20 >>>.10.000 MHz / 1116 etc. >>>=20 >>>I shall send a continuous carrier as and when conditions permit. >>>=20 >>>My newly built VLF TX is working well and can deliver about 150 watts= of=20 >>>RF. >>>On this occasion I shall be using the original (fairly lossy) loading= =20 >>>coil but am presently making a more efficient one. >>>=20 >>>All reports will be most welcome. >>>=20 >>>73 >>>Chris G3XIZ >>>=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 >> >> =20 > =20 --0-2056673091-1297463967=:31788 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Mal,

I calculate the PA including the mains transformer= is about 70% efficient.

The push-pull FET's are wired to the 10 -= 0 - 10V windings and the output tappings are at 0 and 240 volts.
It ha= s a laminated iron core.
The measured secondary voltage is about 350 vo= lts rms so I dare not push the output power any higher.
I'm hoping that= with a more efficient loading coil the secondary voltage will reduce and= I can then push more power, hence current into the aerial.

I initi= ally tried a LOPT but found the power output very limited.
Maybe I was= doing something wrong !

73 Chris G3XIZ

From: mal hamilton <g3kevmal@talktalk.net>
To: rsgb_lf_group@blackshee= p.org
Sent: Fri, 11 Fe= bruary, 2011 16:15:43
Subject: Re: LF: VLF Transmissions - G3XIZ - 12th / 13th February

=20
Chris
How efficient is ur mains transformer at 9 Khz,= what sort=20 of core, ferrite or laminated iron
I assume from what u say you couple your 5 ohm= impedence=20 PA to this transformer PRIM and output from the SEC to the antenna loading= coil.=20 Is the PRIM normal 250v and what is the sec voltage. or do u use a 6v wind= ing.=20 etc
I have a selection of mains transformers which= I could ck=20 out.
Have u tried instead a LOPT
de mal/g3kev
 
----- Original Message -----
From:=20 Chris Osb= orn=20
Sent: Thursday, February 10, 201= 1 7:23=20 PM
Subject: Re: LF: VLF Transmissio= ns -=20 G3XIZ - 12th / 13th February

Mal,=20 Roger, Stefan and group

Thanks for the good wishes.
It will al= l=20 depend on weather conditions as to whether I can fly the balloons but I= shall=20 keep you posted via the reflector.

I can try longer QRSS periods= but=20 begrudge the long wasted 'off' times especially if I'm having trouble ke= eping=20 the balloons aloft.
A compromise would be for me to manually cut the= =20 carrier for 5-10 minute periods.

The transmitter feeds the loadin= g coil=20 and aerial via a large step up (mains) transformer.
The TX/ transform= er=20 will push its RF power into 2000 - 3000 ohms which is an approximation= of the=20 aerial circuit resistance when resonant..
I tried using a 50 ohms TX= output=20 and link coupling to the loading coil but without success.

The ae= rial=20 current should be as before about 0.15 - 0.2 A

73
Chris G3XIZ<= br>


From: Stefan Sch=E4fer= =20 <schaefer@iup.uni-heidelberg.de>
To:=20 rsgb_lf_group@blacksheep.org
Se= nt: Thu, 10 February, 2011=20 19:05:02
Subject: Re= : LF: VLF=20 Transmissions - G3XIZ - 12th / 13th February

Hi Chris,
I=20 think DFCW-600 or even 2400 is a good compromise between a constant carr= ier=20 and some ID but 60 is probably to fast. Jim received you in less than 2= mHz if=20 i remember correctly. QRSS60 is to fast for that. Looking forward to you= r=20 results :-)

73, Stefan

Am 10.02.2011 18:52, schrieb Roger= =20 Lapthorn:=20
Hi Chris,

Very good luck. I'll be looki= ng for=20 you and hoping for success this time.

An email direct and to= this=20 group saying when TX starts/ends would be helpful. Don't suppose you= can=20 send QRSS60 or similar to help with ID? Have passed the word on to Nic= k=20 G4IKZ as he is closer to you than me and not sure he subscribes to thi= s=20 list.

73s
Roger G3XBM


On 10 February 2011 14:42, Chris Osborn <g3xiz@yahoo.co.uk>=20 wrote:
LF,
 
I have had permission to transmit on VLF this coming weekend:= 12th=20 and 13th February.
Weather permitting I shall try again with my balloon-launched= aerial,=20 hopefully about 50m vertical.
 
The frequency will be
 
8.976 66 kHz  (i.e. 10.000 MHz / 1114) and is deriv= ed=20 from an oven controlled xtal oscillator.
Hopefully the frequency will be more stable than last time.
If this frequency proves unsuitable I can transmit on 10.000 MH= Z /=20 1112 . .10.000 MHz / 1116  etc.
 
I shall send a continuous carrier as and when conditions=20 permit.
 
My newly built VLF TX is working well and can deliver about 150= watts=20 of RF.
On this occasion I shall be using the original (fairly lossy)= loading=20 coil but am presently making a more efficient one.
 
All reports will be most welcome.
 
73
Chris G3XIZ
 
 




--=20
g3xbm-qrp.blogspot.com/
www.g3xbm.co.uk
www.y= outube.com/user/g3xbm
G3XBM   GQRP=20 1678    ISWL G11088
=3D""
   <= /td>

 
=3D""=20   =20      
 =20
 =20
<= /td>
<= /table>
<= img width=3D"1" height=3D"1">
<= img width=3D"1" height=3D"1">
<= img width=3D"1" height=3D"1">
<= /tbody>

=

=20


--0-2056673091-1297463967=:31788--