Return-Path: X-Spam-DCC: paranoid 1182; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,HTML_MESSAGE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u98CSsJ5007148 for ; Sat, 8 Oct 2016 14:28:55 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1bsqgi-0000oZ-IM for rs_out_1@blacksheep.org; Sat, 08 Oct 2016 13:25:12 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1bsqgh-0000oQ-TK for rsgb_lf_group@blacksheep.org; Sat, 08 Oct 2016 13:25:11 +0100 Received: from omr-a009e.mx.aol.com ([204.29.186.49]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.87) (envelope-from ) id 1bsqge-0004Xw-Kq for rsgb_lf_group@blacksheep.org; Sat, 08 Oct 2016 13:25:10 +0100 Received: from mtaomg-mce02.mx.aol.com (mtaomg-mce02.mx.aol.com [172.29.27.208]) by omr-a009e.mx.aol.com (Outbound Mail Relay) with ESMTP id E07533800040 for ; Sat, 8 Oct 2016 08:25:02 -0400 (EDT) Received: from core-acb04f.mail.aol.com (core-acb04.mail.aol.com [172.27.24.4]) by mtaomg-mce02.mx.aol.com (OMAG/Core Interface) with ESMTP id 7CB8838000083 for ; Sat, 8 Oct 2016 08:25:02 -0400 (EDT) Received: from 188.192.95.60 by webprd-m89.mail.aol.com (10.74.55.28) with HTTP (WebMailUI); Sat, 08 Oct 2016 08:25:01 -0400 Date: Sat, 8 Oct 2016 08:25:01 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <157a440eec0-52d4-3118@webprd-m89.mail.aol.com> In-Reply-To: <57F83029.8010104@posteo.de> MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [188.192.95.60] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1475929502; bh=2GrDqPCicVdhMwwECPopdBI4AooFn9Ksbjvf8NWoGGg=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=Bb6OgLp66wSxJBzNa2WueijFLu9jmnuLUozjrD0gi+V0FWvnutx2M8C753TQY/rEZ 3CSmlMZzXiLNS+xS5U3a5AvNwvZ8fJwEmjDMmTMDwIbZ2YkqWnORKjSLLb/v5P8xWM 2YSnv8flP9qn7qcUc/paeRUZpTL1NJaUSJGp47nM= x-aol-sid: 3039ac1d1bd057f8e59e07ad X-Scan-Signature: c8ff00257edaad8e124ab9389da9609a Subject: Re: ULF: A new step on the large ULF coil... Content-Type: multipart/alternative; boundary="----=_Part_16207_94769079.1475929501374" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.11 Status: RO X-Status: X-Keywords: X-UID: 8966 ------=_Part_16207_94769079.1475929501374 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable ...she's a Beauty! Yes, I also think the idea of augmenting the new stacked= coil with the yoghurt-coil should work well. The mutual coupling will help= to increase the inductance, and you can fine-tune by adjusting the vertica= l position. With the votage shared between the two coils, you could comfort= ably run > 0.25 A at 2.97 kHz, 15 dB more than your last ULF experinment. T= his might well be strong enough to be detected in Todmorden. Best 73, Markus -----Urspr=C3=BCngliche Mitteilung-----=20 Von: DK7FC An: rsgb_lf_group Verschickt: Sa, 8 Okt 2016 1:32 am Betreff: ULF: A new step on the large ULF coil... Hi ULF,=20 This night i have completed the 4th stack of my large ULF loading coil.=20 An image: https://dl.dropboxusercontent.com/u/19882028/ULF/20161008_ULF_TX= _coil.jpg The exciting question was, what is the new resonance frequency together wi= th my antenna. In the lab i put an equivalent C in parallel and found the r= esonance peak at 3.67 kHz. So the L seems to be 3.8 H now. This is still no= t enough. The l/d of the coil dimension becomes larger now, so i need more = and more wire to reach the final resonance frequency of 2.97 kHz at about 5= 00 pF. I will do a next test on the actual resonance frequency in some days, when= the WX permits. I will also check where the resonance can be found when sw= itching the small coil in series that i use for 6.47 kHz now. It could be q= uite close to 2.97 kHz then! So maybe this allows a next QRO step on 2.97 k= Hz: 100 mA antenna current must be reached for the planned experiment in 65= km distance. BTW the 4 stack coil is wound out of almost 4 kg of enameled Cu wire with = 0.4 mm diameter. The layers are isolated by Kapton tape. My assumption is t= hat it will hold 20 kV now. Ah and the DC resistance is 445 Ohm now. When connecting 275 V AC / 50 Hz,= i can measure 269 mA. So the actual inductance is 2.93 H (beeing farer awa= y from the self resonance frequency) I can tell you it's quite fascinating to operate down on these low frequen= cies :-) To be continued... 73, Stefan/DK7FC ------=_Part_16207_94769079.1475929501374 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
...she's a Beauty! Yes, I also think&n= bsp;the idea of augmenting the new stacked coil with the yog= hurt-coil should work well. The mutual coupling will help to= increase the inductance, and you can fine-tune by adjusting the verti= cal position. With the votage shared between the two coils, you could = comfortably run > 0.25 A at 2.97 kHz, 15 dB more than your las= t ULF experinment. This might well be strong enough to be detected in = Todmorden.

Best 73,
Markus




-----Urspr=C3=BCngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_gr= oup <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 8 = Okt 2016 1:32 am
Betreff: ULF: A new step on the large ULF = coil...

Hi ULF,

This night i have completed the 4th stack of my large ULF l= oading coil.
An image: https://dl.dropboxusercontent.com/u/1988= 2028/ULF/20161008_ULF_TX_coil.jpg

The exciting question was, what is the new resonance frequency together with my antenna. In the lab i put an equivalent C in parallel and found the resonance peak at 3.67 kHz. So the L seems to be 3.8 H now. This is still not enough. The l/d of the coil dimension becomes larger now, so i need more and more wire to reach the final resonance frequency of 2.97 kHz at about 500 pF.

I will do a next test on the actual resonance frequency in some days, when the WX permits. I will also check where the resonance can be found when switching the small coil in series that i use for 6.47 kHz now. It could be quite close to 2.97 kHz then! So maybe this allows a next QRO step on 2.97 kHz: 100 mA antenna current must be reached for the planned experiment in 65 km distance.

BTW the 4 stack coil is wound out of almost 4 kg of enameled Cu wire with 0.4 mm diameter. The layers are isolated by Kapton tape. My assumption is that it will hold 20 kV now.
Ah and the DC resistance is 445 Ohm now. When connectin= g 275 V AC / 50 Hz, i can measure 269 mA. So the actual inductance is 2.93 H (beeing farer away from the self resonance frequency)

I can tell you it's quite fascinating to operate down on these low frequencies :-) To be continued...

73, Stefan/DK7FC
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