Return-Path: Received: from mtain-me10.r1000.mx.aol.com (mtain-me10.r1000.mx.aol.com [172.29.96.146]) by air-ma02.mail.aol.com (v129.4) with ESMTP id MAILINMA021-b4f34d55bd5d3a6; Fri, 11 Feb 2011 17:51:09 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-me10.r1000.mx.aol.com (Internet Inbound) with ESMTP id 768B6380000AF; Fri, 11 Feb 2011 17:51:07 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Po1of-0005MK-Ji for rs_out_1@blacksheep.org; Fri, 11 Feb 2011 22:50:17 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Po1oe-0005MB-QO for rsgb_lf_group@blacksheep.org; Fri, 11 Feb 2011 22:50:16 +0000 Received: from nm16.bullet.mail.sp2.yahoo.com ([98.139.91.86]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1Po1oc-0003so-Om for rsgb_lf_group@blacksheep.org; Fri, 11 Feb 2011 22:50:16 +0000 Received: from [98.139.91.69] by nm16.bullet.mail.sp2.yahoo.com with NNFMP; 11 Feb 2011 22:50:07 -0000 Received: from [98.139.91.57] by tm9.bullet.mail.sp2.yahoo.com with NNFMP; 11 Feb 2011 22:50:07 -0000 Received: from [127.0.0.1] by omp1057.mail.sp2.yahoo.com with NNFMP; 11 Feb 2011 22:50:07 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 225155.17008.bm@omp1057.mail.sp2.yahoo.com Received: (qmail 55510 invoked by uid 60001); 11 Feb 2011 22:50:06 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1297464606; bh=s1s3auholjwzxu3qHoSBgJZvBdaI4ZQEu4rDfGJ3iqc=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=dkmBo2X8fiMdDcqxCJ8Wn+NEsu0noEjR2FWr2keC8L2C9244pJRPBtJOHnHOPXbtf+HPzk6E4MfLzpGcmTpj4axFVFnItHwVqeAkveY3wKeuxieCsKDuZ7c2YGDtZoRCw0K5PFwyofch8K6f/dyq1PRfnRe6O4jw5LxDSP5wxoo= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=k3VX3Y5R2H7LS6NX9/MUcBN0a/cESWxGr2ZZl3HGRdQN/R9uGagUypx56BrwBNOFb69vFb7uk3srpbhsFtBAWw5RfPkUZzvjgkanlOP2T2te1KCEYmpdegldwTXazyyhKTMJfMesvUHG01uUFUHhOQjW0zc1OcRr9RhsKdFfiI4=; Message-ID: <786172.54803.qm@web111920.mail.gq1.yahoo.com> X-YMail-OSG: BkLq8RsVM1mJ35U4tux9m_ViLpedVyS.ctP.n2NlVrJ.eQa VANJXd5PdRRIxolqvqgQYbewMJnCZ.kvyWLBxatyrF6njJTPCSced5VSTWuA ZwLvw03acDZ.9GM.3_BD.0mKo5JuXAav2WZp6eq6uD2Y3_Isi4PDi_CZGStp pxgH9h9hD_Doos3aEHnep0_n2RbghkIyBoeg7wUZmHtrKpdjNGPFcgzLV3FL OoFcqJC7r4FfNRtOIZIz3vj0HSvwlWJ9BtIrxqzMk0czrPGCblCcxOS.aYjm KMctJkR9pdDd2QCyjScI_l5YQoPOGF9o6jvX.9In52PHQMyf3SEXuN19YuiC KhsXSGLx1c9wS1TLb Received: from [87.1.202.102] by web111920.mail.gq1.yahoo.com via HTTP; Fri, 11 Feb 2011 14:50:06 PST 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> <690897.31788.qm@web28511.mail.ukl.yahoo.com> Date: Fri, 11 Feb 2011 14:50:06 -0800 (PST) From: Daniele Tincani To: rsgb_lf_group@blacksheep.org In-Reply-To: <690897.31788.qm@web28511.mail.ukl.yahoo.com> MIME-Version: 1.0 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: VLF Transmissions - G3XIZ - 12th / 13th February Content-Type: multipart/alternative; boundary="0-1281320398-1297464606=:54803" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.7 required=5.0 tests=FORGED_YAHOO_RCVD,HTML_60_70, 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-d307.1 ; domain : yahoo.com DKIM : pass x-aol-sid: 3039ac1d60924d55bd5a6ec0 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0-1281320398-1297464606=:54803 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi Chris, when do you plan to start tx tomorrow? Regards Daniele ________________________________ From: Chris Osborn To: rsgb_lf_group@blacksheep.org Sent: Fri, February 11, 2011 11:39:27 PM Subject: Re: LF: VLF Transmissions - G3XIZ - 12th / 13th February 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 Chris How efficient is ur mains transformer at 9 Khz, what sort of core, ferrite= or=20 laminated iron I assume from what u say you couple your 5 ohm impedence PA to this transf= ormer=20 PRIM and output from the SEC to the antenna loading coil. Is the PRIM norm= al=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 ----- 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 ball= oons=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 minute= =20 >periods. > >The transmitter feeds the loading coil and aerial via a large step up (ma= ins)=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 coil= 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 car= rier=20 >and some ID but 60 is probably to fast. Jim received you in less than 2= mHz if i=20 >remember correctly. QRSS60 is to fast for that. Looking forward to your= results=20 >:-) > >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 he= lpful.=20 >>Don't suppose you can send QRSS60 or similar to help with ID? Have passe= d the=20 >>word on to Nick G4IKZ as he is closer to you than me and not sure he sub= scribes=20 >>to this list. >> >>73s >>Roger G3XBM >> >> >> >>On 10 February 2011 14:42, Chris Osborn wrote: >> >>LF, >>> >>>I have had permission to transmit on VLF this coming weekend: 12th and= 13th=20 >>>February. >>>Weather permitting I shall try again with my balloon-launched aerial,= hopefully=20 >>>about 50m vertical. >>> >>>The frequency will be=20 >>> >>>8.976 66 kHz=A0 (i.e. 10.000 MHz / 1114) and is derived from an oven co= ntrolled=20 >>>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=A0 etc. >>> >>>I shall send a continuous carrier as and when conditions permit. >>> >>>My newly built VLF TX is working well and can deliver about 150 watts= of RF. >>>On this occasion I shall be using the original (fairly lossy) loading= coil but=20 >>>am=A0presently making a more efficient one. >>> >>>All reports will be most welcome. >>> >>>73 >>>Chris G3XIZ >>> >>> >>> >> >> >>--=20 >>g3xbm-qrp.blogspot.com/ >>www.g3xbm.co.uk >>www.youtube.com/user/g3xbm >>G3XBM=A0=A0 GQRP 1678=A0=A0=A0 ISWL G11088 >> >>=20 >>=A0 =A0 =20 >> >> =A0 =A0 =A0 =A0 =A0 =20 >> =20 >>=A0 =20 >>=A0 =20 >> >> =20 >> =20 >> >> =20 >> =20 >> >> =20 > =20 --0-1281320398-1297464606=:54803 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi Chris, when do you plan to start tx tomorrow?
Regards
Daniele
=
From: Chris Osborn <g3x= iz@yahoo.co.uk>
To:= rsgb_lf_group@blacksheep.org
Sent= : Fri, February 11, 2011 11:39:27 PM
Subject: Re: LF: VLF Transmissions - G3XIZ - 12th= / 13th February

Mal,

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

The push-pull FET's are wired to the 10 - 0 - 10= V windings and the output tappings are at 0 and 240 volts.
It has a lam= inated iron core.
The measured secondary voltage is about 350 volts 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 initially= tried a LOPT but found the power output very limited.
Maybe I was doin= g something wrong !

73 Chris G3XIZ
=
From: mal hamilton <g3k= evmal@talktalk.net>
To:<= /B> rsgb_lf_group@blacksheep.org
S= ent: Fri, 11 February, 2011 16:15:43
Subject: Re: LF: VLF Transmissions - G3XIZ - 12th= / 13th February

Chris
How efficient is ur mains transformer at 9 Khz, wh= at sort of core, ferrite or laminated iron
I assume from what u say you couple your 5 ohm imp= edence PA to this transformer PRIM and output from the SEC to the antenna= loading coil. Is the PRIM normal 250v and what is the sec voltage. or do= u use a 6v winding. etc
I have a selection of mains transformers which I= could ck out.
Have u tried instead a LOPT
de mal/g3kev
 
----- Original Message -----
From:= Chris Osborn=
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 but= I shall keep you posted via the reflector.

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

The transmitter fee= ds the loading coil and aerial via a large step up (mains) transformer.The TX/ transformer will push its RF power into 2000 - 3000 ohms which is= an approximation of the aerial circuit resistance when resonant..
I tr= ied using a 50 ohms TX output and link coupling to the loading coil but wi= thout success.

The aerial current should be as before about 0.15 -= 0.2 A

73
Chris G3XIZ

=
From: Stefan Sch=E4fer <= ;schaefer@iup.uni-heidelberg.de>
Sent: Thu, 10 February, 2011 19:05:02
Subject: Re: LF: VLF Transmissions= - G3XIZ - 12th / 13th February

Hi Chris,

I think DF= CW-600 or even 2400 is a good compromise between a constant carrier and so= me ID but 60 is probably to fast. Jim received you in less than 2 mHz if= i remember correctly. QRSS60 is to fast for that. Looking forward to your= 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.

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

73s
Roger G3XBM


On 10 February 2011 14:42, Chris Osborn <g3xiz@yahoo.co.uk>= wrote:
LF,
 
I have had permission to transmit on VLF this coming weekend: 12th an= d 13th February.
Weather permitting I shall try again with my balloon-launched aerial,= hopefully about 50m vertical.
 
The frequency will be
 
8.976 66 kHz  (i.e. 10.000 MHz / 1114) and is derived fro= m 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 MHZ / 11= 12 . .10.000 MHz / 1116  etc.
 
I shall send a continuous carrier as and when conditions permit.
 
My newly built VLF TX is working well and can deliver about 150 watts= of RF.
On this occasion I shall be using the original (fairly lossy) loading= coil but am presently making a more efficient one.
 
All reports will be most welcome.
 
73
Chris G3XIZ
 
 



--
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www.g3xbm.co.uk
www.youtube.co= m/user/g3xbm
G3XBM   GQRP 1678    ISWL G11= 088
=
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