Return-Path: X-Spam-DCC: paranoid 1481; Body=3 Fuz1=3 Fuz2=3 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 u9RAWWkI021736 for ; Thu, 27 Oct 2016 12:32:32 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1bzhvA-0002Di-AR for rs_out_1@blacksheep.org; Thu, 27 Oct 2016 11:28:28 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1bzhv2-0002DZ-Lg for rsgb_lf_group@blacksheep.org; Thu, 27 Oct 2016 11:28:20 +0100 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 1bzhux-0006Hz-5E for rsgb_lf_group@blacksheep.org; Thu, 27 Oct 2016 11:28:19 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id A89CF20A8A for ; Thu, 27 Oct 2016 12:28:04 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3t4NPw3W8Lz1018 for ; Thu, 27 Oct 2016 12:28:03 +0200 (CEST) Message-ID: <5811D6B3.7090201@posteo.de> Date: Thu, 27 Oct 2016 12:28:03 +0200 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> In-Reply-To: <579355A36AEE9D4FA555C45D556003AB5D83FBD7@servigilant.vigilant.local> X-Scan-Signature: 611f9af8a0f6ba007b1ec6dce409caf4 Subject: Re: ULF: A new step on the large ULF coil... Content-Type: multipart/alternative; boundary="------------060706050306040503030009" 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: 9834 Status: O X-Status: X-Keywords: X-UID: 9250 This is a multi-part message in MIME format. --------------060706050306040503030009 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit 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 > --------------060706050306040503030009 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit 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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