Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mb01.r1000.mx.aol.com (Internet Inbound) with ESMTP id E18E538000094; Fri, 25 Nov 2011 14:16:44 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RU1FG-0007Ur-Fn for rs_out_1@blacksheep.org; Fri, 25 Nov 2011 19:15:34 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RU1FF-0007Ui-SM for rsgb_lf_group@blacksheep.org; Fri, 25 Nov 2011 19:15:33 +0000 Received: from out1.ip09ir2.opaltelecom.net ([62.24.128.245]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RU1FD-0001Do-GB for rsgb_lf_group@blacksheep.org; Fri, 25 Nov 2011 19:15:33 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApMBAEzoz05Oln1u/2dsb2JhbAAMOIJNqykBAQEBA2cREQsJDwkWDwkDAgECAUUTCAEBvh+KYgSNIpkz X-IronPort-AV: E=Sophos;i="4.69,572,1315177200"; d="scan'208,217";a="498116423" Received: from host-78-150-125-110.as13285.net (HELO [192.168.2.2]) ([78.150.125.110]) by out1.ip09ir2.opaltelecom.net with ESMTP; 25 Nov 2011 19:15:24 +0000 Message-ID: <4ECFE94B.7090703@talktalk.net> Date: Fri, 25 Nov 2011 19:15:23 +0000 From: qrss User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: ,<66E491BAB91C48AF81191F4022525A14@DennisPC> <6FE757960E6C447781689D4F19A315AE@DennisPC> <4EC2C6EB.2080201@iup.uni-heidelberg.de> <4EC2DB14.9000807@talktalk.net> <4ECFD8B6.2050601@iup.uni-heidelberg.de> In-Reply-To: <4ECFD8B6.2050601@iup.uni-heidelberg.de> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: VLF: 8970 Hz transmissions, soon again here Content-Type: multipart/alternative; boundary="------------010207020005010300060708" 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-SCORE: 0:2:484109856:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d60154ecfe99b3b6a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------010207020005010300060708 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit FB Stefan We still have a big lack of sunshine so the Grabber is going on now with battery on float charger which I will remove in the morning. Good luck. hope the WX holds out. Eddie On 25/11/2011 18:04, Stefan Schäfer wrote: > Eddie, VLF, > > The coil and PA and all the parts are here now and maybe i will do > first tests tomorrow in the afternoon on 8970 Hz. > > The goals would be to resonate on the frequency and apply 50 kV rms or > more. Oh i just calculated: My coil has about 550 mH and the antenna > 473 pF. So i need about 100 pF from somewhere else, remembering my > homemade plate capacitor with the cola bottles as the spacing > insolator ;-) The coil has about 320 Ohm DC resistance and if i > actually want to apply 50 kV, i would need 1.2 kW for that. No problem > for the PA i think. The ERP will be below 1 mW anyway :-( > > But the background noise is extremely low in the last time and if i > can a stable signal over several hours i expect to be visible in many > spectrograms. > > 73, Stefan/DK7FC > > Am 15.11.2011 22:35, schrieb qrss: >> Stefan >> >> I look forward to your tests, please try and give me a warning even >> for the spontaneous tests so I can leave my Grabber, >> http://g3zjo.bplaced.net , on overnight if needed. Also, due to lack >> of sunshine on the solar panel here, I have been running a dirty >> earth supply to charge the battery, during tests I can remove this >> for cleaner signals. >> >> 73 Eddie G3ZJO >> >> >> On 15/11/2011 20:09, Stefan Schäfer wrote: >>> VLF, >>> >>> Am 15.11.2011 17:03, schrieb DENNIS EASTERLING: >>>> [...] I also have a mini-whip, but this has been extended for >>>> VLF purposes. [...] >>> >>> ...which is good since soon there will be some activity again on >>> 8970 Hz. If you like you can join in to the group of successful >>> listeners on the 33 km band. >>> >>> Yesterday i carried my TX coil to the fixed antenna here. Also the >>> PA and variometer part of course. I do inted to use the fixed antenna. >>> I did some calculations about the radiation resistance and losses >>> and power at maximum voltage (50 kV rms on the wire) and found that >>> the ERP will be about 10 dB higher than expected, i.e. i could >>> radiate something in the range of many 100 uW up to 1 mW or >>> theoretically up to 2 mW. We will see and measure. >>> >>> Paul Nicholsen reported about a very senistive receiver in USA that >>> allows long time integration, i.e. not producing a spectrogram but >>> integrating a given TX time into a single bin, like Paul usually does. >>> Here on the fixed antenna i could do night transmissions. 500W TX >>> power key down for 24h is no problem (as long as there is no rain). >>> >>> So i am optimistic and looking forward to some new work on the >>> dreamers band! >>> >>> Also i would be interested if there is (still) some interest in VLF >>> in this group. For Paul, a endless straight "carrier" would be the >>> optimium while a radio amateur may like to have some true ID and >>> maybe a message to be read and displayed. What about the grabber >>> runners and new prepared VLF receiving stations? >>> >>> Probably i will start next week but may do some spontaneous tests >>> before... >>> >>> 73, Stefan/DK7FC >>> >>> PS: I would like to see other VLF transmitting stations as well. >>> What about G3XIZ, DF6NM, OE3GHB, OE5ODL, OK2BVG, DJ8WX? We all could >>> leave some common traces again in the excellent dark spectrogram >>> backgrounds! >>> >>> >> --------------010207020005010300060708 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit FB Stefan

We still have a big lack of sunshine so the Grabber is going on now with battery on float charger which I will remove in the morning.

Good luck. hope the WX holds out.

Eddie

On 25/11/2011 18:04, Stefan Schäfer wrote:
Eddie, VLF,

The coil and PA and all the parts are here now and maybe i will do first tests tomorrow in the afternoon on 8970 Hz.

The goals would be to resonate on the frequency and apply 50 kV rms or more. Oh i just calculated: My coil has about 550 mH and the antenna 473 pF. So i need about 100 pF from somewhere else, remembering my homemade plate capacitor with the cola bottles as the spacing insolator ;-) The coil has about 320 Ohm DC resistance and if i actually want to apply 50 kV, i would need 1.2 kW for that. No problem for the PA i think. The ERP will be below 1 mW anyway :-(

But the background noise is extremely low in the last time and if i can a stable signal over several hours i expect to be visible in many spectrograms.

73, Stefan/DK7FC

Am 15.11.2011 22:35, schrieb qrss:
Stefan

I look forward to your tests, please try and give me a warning even for the spontaneous tests so I can leave my Grabber, http://g3zjo.bplaced.net , on overnight if needed. Also, due to lack of sunshine on the solar panel here, I have been running a dirty earth supply to charge the battery, during tests I can remove this for cleaner signals.

73 Eddie G3ZJO


On 15/11/2011 20:09, Stefan Schäfer wrote:
VLF,

Am 15.11.2011 17:03, schrieb DENNIS EASTERLING:
[...] I also have a mini-whip, but this has been extended for
VLF purposes. [...]

...which is good since soon there will be some activity again on 8970 Hz. If you like you can join in to the group of successful listeners on the 33 km band.

Yesterday i carried my TX coil to the fixed antenna here. Also the PA and variometer part of course. I do inted to use the fixed antenna.
I did some calculations about the radiation resistance and losses and power at maximum voltage (50 kV rms on the wire) and found that the ERP will be about 10 dB higher than expected, i.e. i could radiate something in the range of many 100 uW up to 1 mW or theoretically up to 2 mW. We will see and measure.

Paul Nicholsen reported about a very senistive receiver in USA that allows long time integration, i.e. not producing a spectrogram but integrating a given TX time into a single bin, like Paul usually does.
Here on the fixed antenna i could do night transmissions. 500W TX power key down for 24h is no problem (as long as there is no rain).

So i am optimistic and looking forward to some new work on the dreamers band!

Also i would be interested if there is (still) some interest in VLF in this group. For Paul, a endless straight "carrier" would be the optimium while a radio amateur may like to have some true ID and maybe a message to be read and displayed. What about the grabber runners and new prepared VLF receiving stations?

Probably i will start next week but may do some spontaneous tests before...

73, Stefan/DK7FC

PS: I would like to see other VLF transmitting stations as well. What about G3XIZ, DF6NM, OE3GHB, OE5ODL, OK2BVG, DJ8WX? We all could leave some common traces again in the excellent dark spectrogram backgrounds!




--------------010207020005010300060708--