Return-Path: Received: from mtain-da04.r1000.mx.aol.com (mtain-da04.r1000.mx.aol.com [172.29.64.76]) by air-md09.mail.aol.com (v129.4) with ESMTP id MAILINMD091-8b944d55610c17c; Fri, 11 Feb 2011 11:17:16 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-da04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 699EC380000B8; Fri, 11 Feb 2011 11:17:14 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Pnvf7-0000Zz-Fv for rs_out_1@blacksheep.org; Fri, 11 Feb 2011 16:16:01 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Pnvf5-0000Zq-Q1 for rsgb_lf_group@blacksheep.org; Fri, 11 Feb 2011 16:15:59 +0000 Received: from out1.ip03ir2.opaltelecom.net ([62.24.128.239]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Pnvf3-0001cW-Kr for rsgb_lf_group@blacksheep.org; Fri, 11 Feb 2011 16:15:59 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AiYBACHvVE1cHYvE/2dsb2JhbACCS5Bng2WOXXO7JIVdBIFjjWWCcg X-IronPort-AV: E=Sophos;i="4.60,455,1291593600"; d="scan'208,217";a="337460832" Received: from unknown (HELO xphd97xgq27nyf) ([92.29.139.196]) by out1.ip03ir2.opaltelecom.net with SMTP; 11 Feb 2011 16:15:49 +0000 Message-ID: <004c01cbca06$f1b88f50$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <988315.45122.qm@web28515.mail.ukl.yahoo.com> <4D5436DE.3040602@iup.uni-heidelberg.de> <673772.16865.qm@web28515.mail.ukl.yahoo.com> Date: Fri, 11 Feb 2011 16:15:43 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 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="----=_NextPart_000_0049_01CBCA06.F17CE5E0" 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_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-sid: 3039ac1d404c4d5561090d7e X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_0049_01CBCA06.F17CE5E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Chris How efficient is ur mains transformer at 9 Khz, what sort of core, fer= rite or laminated iron I assume from what u say you couple your 5 ohm impedence PA to this tr= ansformer 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 wi= nding. 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= balloons but I shall keep you posted via the reflector. I can try longer QRSS periods but begrudge the long wasted 'off' tim= es especially if I'm having trouble keeping the balloons aloft. A compromise would be for me to manually cut the carrier for 5-10 mi= nute periods. The transmitter feeds the loading coil and aerial via a large step= up (mains) transformer. The TX/ transformer will push its RF power into 2000 - 3000 ohms whi= ch is an approximation of the aerial circuit resistance when resonant.= . I tried using a 50 ohms TX output and link coupling to the loading= coil but 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 constan= t carrier and some 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 thi= s time.=20 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 Nick 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 wrote: LF, I have had permission to transmit on VLF this coming weekend: 12= th and 13th February. Weather permitting I shall try again with my balloon-launched ae= rial, hopefully about 50m vertical. The frequency will be=20 8.976 66 kHz (i.e. 10.000 MHz / 1114) and is derived from an ov= en 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 . .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) lo= ading 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.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 ------=_NextPart_000_0049_01CBCA06.F17CE5E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
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 loa= ding coil.=20 Is the PRIM normal 250v and what is the sec voltage. or do u use a 6v= winding.=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= Osborn=20
Sent: Thursday, February 10,= 2011 7:23=20 PM
Subject: Re: LF: VLF Transmis= sions -=20 G3XIZ - 12th / 13th February

Mal,=20 Roger, Stefan and group

Thanks for the good wishes.
It wil= l all=20 depend on weather conditions as to whether I can fly the balloons bu= t I shall=20 keep you posted via the reflector.

I can try longer QRSS peri= ods but=20 begrudge the long wasted 'off' times especially if I'm having troubl= e keeping=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 lo= ading coil=20 and aerial via a large step up (mains) transformer.
The TX/ trans= former=20 will push its RF power into 2000 - 3000 ohms which is an approximati= on 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.

Th= e aerial=20 current should be as before about 0.15 - 0.2 A

73
Chris G3= XIZ


From: Stefan Sch=E4f= er=20 <schaefer@iup.uni-heidelberg.de>
To:=20 rsgb_lf_group@blacksheep.org
Sent: 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= carrier=20 and some ID but 60 is probably to fast. Jim received you in less tha= n 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 Ro= ger=20 Lapthorn:=20
Hi Chris,

Very good luck. I'll be= looking 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= Nick=20 G4IKZ as he is closer to you than me and not sure he subscribes to= this=20 list.

73s
Roger G3XBM


On 10 February 2011 14:42, Chris Osborn= <g3= xiz@yahoo.co.uk>=20 wrote:
LF,
 
I have had permission to transmit on VLF this coming weeken= d: 12th=20 and 13th February.
Weather permitting I shall try again with my balloon-launch= ed aerial,=20 hopefully about 50m vertical.
 
The frequency will be
 
8.976 66 kHz  (i.e. 10.000 MHz / 1114) and is= derived=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 10.00= 0 MHZ /=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 loss= y) 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.youtube.com/user/g3xbm
G3XBM =   GQRP=20 1678    ISWL G11088
3D""
 = ;  
 
=20   3D""=20      
= =
 =20
 = =20



=20

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