Return-Path: X-Spam-DCC: paranoid 1480; 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=-0.3 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_50_60,HTML_MESSAGE,HTML_TITLE_EMPTY,RATWARE_GECKO_BUILD,SPF_PASS 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 u9VD6n6C011118 for ; Mon, 31 Oct 2016 14:06:49 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1c1CDS-0005k6-3M for rs_out_1@blacksheep.org; Mon, 31 Oct 2016 13:01:30 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1c1CDR-0005jx-BS for rsgb_lf_group@blacksheep.org; Mon, 31 Oct 2016 13:01:29 +0000 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1c1CDI-0003uF-Sj for rsgb_lf_group@blacksheep.org; Mon, 31 Oct 2016 13:01:28 +0000 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 19B8A2082D for ; Mon, 31 Oct 2016 14:01:14 +0100 (CET) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3t6vcp1VZjzytl for ; Mon, 31 Oct 2016 14:01:13 +0100 (CET) Message-ID: <58174098.5060108@posteo.de> Date: Mon, 31 Oct 2016 14:01:12 +0100 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <579355A36AEE9D4FA555C45D556003AB5D83FBD7@servigilant.vigilant.local> <5811D6B3.7090201@posteo.de> In-Reply-To: <5811D6B3.7090201@posteo.de> X-Scan-Signature: edae4bc128aa121544439b7b7cfd26a1 Subject: Re: ULF: A new step on the large ULF coil... Content-Type: multipart/alternative; boundary="------------040005020508080600050409" 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 Content-Length: 11082 Status: O X-Status: X-Keywords: X-UID: 9317 This is a multi-part message in MIME format. --------------040005020508080600050409 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit I got some feedback that the link to the video wasn't working because Dropbox is blocking the link, they say it causes to much traffic. Its overdue to find an alternative! Here's the link directly from the uni server now: http://www.iup.uni-heidelberg.de/schaefer_vlf/20160702_222257.mp4 73, Stefan Am 27.10.2016 12:28, schrieb DK7FC: > Hi Luis, > > Am 27.10.2016 11:40, schrieb VIGILANT Luis Fernández: >> Amazing work Stefan !! :-O >> I bet you have constructed some kind of support (like a lathe) which >> lets you rotate the pipe easily and wound the coils . Right ? > Right! See: > https://dl.dropboxusercontent.com/u/19882028/ULF/20160702_222257.mp4 > It's quite comfortable but still a lot of work. >> This is getting really heavy and the quality of coils looks very nice >> and repeteable ...... at least five times ! ;-) > 5 kg of copper wire so far. Still quite managable. >> Dumb question: Why do you get different inductance values when >> resonating it with antenna equivalent capacitor and when measuring >> current at 273V AC / 50Hz ?? >> Shouldn't be inductance a constant value ? ...... or I'm missing >> something obvious :( > It's due to the inner-winding capacity which is higher than on a > single layer coil. At the self-resonance frequency you need no > external C to get this resonance, of course. Then add just 10 pF > external C. The new resonance frequency will be almost the same. If > you calculate L from that frequency and C, it will be a gigantic high > value, several GH :-) > Assume the internal C is 100 pF. And L is 4 H. Then f res will be > about 7.9577 kHz. With 10 pF external it will be 7.5874 kHz. If you > ignore the internal C and say "I'm getting 7.5874 kHz with just 10 pF > connected to the L" you would calculate L = 44 H! > So you need to switch a much larger C in parallel to L so that the > internal C becomes irrelevant. Maybe 1 uF, then you will get 79.6 Hz > at 4H. When calculating L with 1.000001 uF (1uF + 100 pF) and 79.6 Hz > you will get 3.997 H, which is quite correct! > It doesn't need to be a resonated circuit of course. You can also > apply a constant voltage and simply measure the current. But you need > to know the DC resistance then. Then Z = U/I = R^2 + XL^2 and L = XL / > 314 (at 50 Hz). > >> Good luck with the 6th floor. Seems that there is no room for a 7th, >> so that's why you mentioned the variometer > I will first build the variometer now on a 16cm diameter and 6cm high > piece of tube. Will see what the tuning range is. You know, actually > i'm not a friend of calculations if i can do an experiment instead :-) > > 73, Stefan >> 73 de Luis >> EA5DOM >> >> ------------------------------------------------------------------------ >> *De:* owner-rsgb_lf_group@blacksheep.org >> [mailto:owner-rsgb_lf_group@blacksheep.org] *En nombre de *DK7FC >> *Enviado el:* miércoles, 26 de octubre de 2016 19:06 >> *Para:* rsgb_lf_group@blacksheep.org >> *Asunto:* Re: ULF: A new step on the large ULF coil... >> >> Hi ULF, >> >> It's just a few weeks ago, now the *5th stack* is wound on the coil: >> *https://dl.dropboxusercontent.com/u/19882028/ULF/20161026_185804.jpg >> * >> The DC resistance rose from 445 Ohm to *572 Ohm*. >> The measured resonance frequency (using the antenna equivalent C in >> the shack) dropped from 3.667 kHz down to *3.208 kHz*. That should be >> about *4.92 H*. >> Measured at 273V AC / 50 Hz, i'm getting 197 mA, so the actual >> inductance is *4.0 H*. >> >> A 6th stack and a variometer part is needed! >> >> 73, Stefan >> --------------040005020508080600050409 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit I got some feedback that the link to the video wasn't working because Dropbox is blocking the link, they say it causes to much traffic. Its overdue to find an alternative!
Here's the link directly from the uni server now: http://www.iup.uni-heidelberg.de/schaefer_vlf/20160702_222257.mp4

73, Stefan

Am 27.10.2016 12:28, schrieb DK7FC:
Hi Luis,

Am 27.10.2016 11:40, schrieb VIGILANT Luis Fernández:
Amazing work Stefan !! :-O
 
I bet you have constructed some kind of support (like a lathe) which lets you rotate the pipe easily and wound the coils . Right ?
Right! See: https://dl.dropboxusercontent.com/u/19882028/ULF/20160702_222257.mp4
It's quite comfortable but still a lot of work.
This is getting really heavy and the quality of coils looks very nice and repeteable ...... at least five times ! ;-)
5 kg of copper wire so far. Still quite managable.
 
Dumb question: Why do you get different inductance values when resonating it with antenna equivalent capacitor and when measuring current at 273V AC / 50Hz  ??
Shouldn't be inductance a constant value ? ...... or I'm missing something obvious :(
It's due to the inner-winding capacity which is higher than on a single layer coil. At the self-resonance frequency you need no external C to get this resonance, of course. Then add just 10 pF external C. The new resonance frequency will be almost the same. If you calculate L from that frequency and C, it will be a gigantic high value, several GH :-)
Assume the internal C is 100 pF. And L is 4 H. Then f res will be about 7.9577 kHz. With 10 pF external it will be 7.5874 kHz. If you ignore the internal C and say "I'm getting 7.5874 kHz with just 10 pF connected to the L" you would calculate L = 44 H!
So you need to switch a much larger C in parallel to L so that the internal C becomes irrelevant. Maybe 1 uF, then you will get 79.6 Hz at 4H. When calculating L with 1.000001 uF (1uF + 100 pF) and 79.6 Hz you will get 3.997 H, which is quite correct!
It doesn't need to be a resonated circuit of course. You can also apply a constant voltage and simply measure the current. But you need to know the DC resistance then. Then Z = U/I = R^2 + XL^2 and L = XL / 314 (at 50 Hz).

 
Good luck with the 6th floor. Seems that there is no room for a 7th, so that's why you mentioned the variometer
I will first build the variometer now on a 16cm diameter and 6cm high piece of tube. Will see what the tuning range is. You know, actually i'm not a friend of calculations if i can do an experiment instead :-)

73, Stefan
 
73 de Luis
EA5DOM

De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: miércoles, 26 de octubre de 2016 19:06
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: ULF: A new step on the large ULF coil...

Hi ULF,

It's just a few weeks ago, now the 5th stack is wound on the coil: https://dl.dropboxusercontent.com/u/19882028/ULF/20161026_185804.jpg

The DC resistance rose from 445 Ohm to 572 Ohm.
The measured resonance frequency (using the antenna equivalent C in the shack) dropped from 3.667 kHz down to 3.208 kHz. That should be about 4.92 H.
Measured at 273V AC / 50 Hz, i'm getting 197 mA, so the actual inductance is 4.0 H.

A 6th stack and a variometer part is needed!

73, Stefan

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