Return-Path: X-Spam-DCC: paranoid 104; 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=-2.5 required=5.0 tests=BAYES_00,FORGED_RCVD_HELO, HTML_MESSAGE,SPF_PASS autolearn=unavailable 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 u3SKRhxt002069 for ; Thu, 28 Apr 2016 22:27:45 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1avsTC-0005xg-L4 for rs_out_1@blacksheep.org; Thu, 28 Apr 2016 21:23:30 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1avsTC-0005xX-1k for rsgb_lf_group@blacksheep.org; Thu, 28 Apr 2016 21:23:30 +0100 Received: from rhcavuit02.kulnet.kuleuven.be ([2a02:2c40:0:c0::25:130] helo=cavuit02.kulnet.kuleuven.be) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1avsT9-0000xp-MU for rsgb_lf_group@blacksheep.org; Thu, 28 Apr 2016 21:23:28 +0100 X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-KULeuven-Scanned: Found to be clean X-KULeuven-ID: A4176128342.AFEBE X-KULeuven-Information: Katholieke Universiteit Leuven Received: from icts-p-smtps-2.cc.kuleuven.be (icts-p-smtps-2e.kulnet.kuleuven.be [134.58.240.34]) by cavuit02.kulnet.kuleuven.be (Postfix) with ESMTP id A4176128342 for ; Thu, 28 Apr 2016 22:23:22 +0200 (CEST) Received: from ICTS-S-EXMBX18.luna.kuleuven.be (icts-s-exmbx18.luna.kuleuven.be [10.112.11.49]) (using TLSv1.2 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by icts-p-smtps-2.cc.kuleuven.be (Postfix) with ESMTPS id A19082003B for ; Thu, 28 Apr 2016 22:23:19 +0200 (CEST) Received: from ICTS-S-EXMBX27.luna.kuleuven.be (10.112.11.62) by ICTS-S-EXMBX18.luna.kuleuven.be (10.112.11.49) with Microsoft SMTP Server (TLS) id 15.0.1156.6; Thu, 28 Apr 2016 22:23:19 +0200 Received: from ICTS-S-EXMBX27.luna.kuleuven.be ([fe80::291a:cc4f:6953:698a]) by ICTS-S-EXMBX27.luna.kuleuven.be ([fe80::291a:cc4f:6953:698a%34]) with mapi id 15.00.1156.000; Thu, 28 Apr 2016 22:23:19 +0200 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Thread-Topic: VLF: T106-52 cores on VLF, continued, thoughts... Thread-Index: AQHRoX0krLsR6fdkBE2D2Tkh2a382Z+f0q+C Date: Thu, 28 Apr 2016 20:23:19 +0000 Message-ID: <1461874994878.61188@fys.kuleuven.be> References: <571CF2AD.9030207@posteo.de> <571D2966.5080104@posteo.de> <571D3034.8020204@mbsks.franken.de> <571D31EE.9030106@posteo.de> <571DD4DE.3080703@abelian.org> <571E54B9.9010208@posteo.de> <571E5C16.2090102@mbsks.franken.de> <571E5F26.1080605@mbsks.franken.de> <571E92A0.3000608@posteo.de> <571E98A7.5070503@posteo.de> <571F87A2.7000700@abelian.org> <571FC3E8.1000706@posteo.de> <5720D81D.6020609@abelian.org> <5720E958.2010104@posteo.de> <572102E9.7020607@posteo.de> <5722503E.3000501@posteo.de>,<572257A4.6090002@posteo.de> In-Reply-To: <572257A4.6090002@posteo.de> Accept-Language: nl-BE, en-GB, en-US Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.112.50.1] MIME-Version: 1.0 X-HELO-Warning: Remote host 2a02:2c40:0:c0::25:130 (rhcavuit02.kulnet.kuleuven.be) used invalid HELO/EHLO cavuit02.kulnet.kuleuven.be - verification failed X-Scan-Signature: 55db901127f87fafbf8ae301dac99c44 Subject: Re: VLF: T106-52 cores on VLF, continued, thoughts... Content-Type: multipart/alternative; boundary="_000_146187499487861188fyskuleuvenbe_" 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: O X-Status: X-Keywords: X-UID: 7901 --_000_146187499487861188fyskuleuvenbe_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Stefan, what about a "fatter" (length/diameter =3D 1) coil filled with some core st= acks in parallel? For a slim coil (large length/diameter ratio) the inductance is more or les= s proportional to the number of windings while for a fat coil inductance is= more or less proportional to the square of the number of windings. But I don't know how effective the cores will be in such a fat coil. 73, Rik ON7YD - OR7T ________________________________ Van: owner-rsgb_lf_group@blacksheep.org namens DK7FC Verzonden: donderdag 28 april 2016 20:34 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: VLF: T106-52 cores on VLF, continued, thoughts... OK, after a break in the sunset i thought: If =B5r tends to 6.5 and L/l to 22 mH/m for 0.5mm wire for l -> infinity, a= nd if i want to keep the coil length at 0.8m, which would be 17.6 mH for 0.= 5mm wire. However i need 788 mH! So i need a 6.7 times smaller wire, i.e. 0= .074mm diameter. This is impossible and i wouldn't carry the antenna curren= t. A new coil would only make sense if i can rise the signal by at least 6 dB.= I just measured 260 mA. So let's say 600 mA would be fine. And i like the = 0.4mm wire and would like to use that. In the moment i see no chance for a single layer coil using this technique = :-( 73, Stefan Am 28.04.2016 20:02, schrieb DK7FC: Hmm, well, ok, after some discussions, the show ehm the experiments must go= on. I'm continuing with a higher l/d ratio. 13 of these cores are available, th= e other ones are parts of my transmit coil now. I like to get 3 measurement= s to approximate a curve showing L/l and =B5r(eff) over the ratio l/d. So a= useful number of cores is 5 (already done, see below), 9 and 13. 5 core stack (yesterdays measurement): The ratio coil diameter / coil length, l/d =3D 49/33 =3D 1.48. Effective =B5r =3D 3.75 L/l =3D 452 =B5H / 49 mm =3D 9.22 mH/m 9 core stack: As a resonance C i use 0.3 uF (measured C =3D 306 nF) The resonance is at 7.26 kHz. The bandwidth is (7.36 - 7.18) kHz =3D 180 Hz= . Q =3D 40. L =3D 1.75 mH Without the cores inside, the resonance is found at f =3D 17.1 kHz. BW is (= 17.6 - 16.69) kHz =3D 1.05 kHz. Q =3D 16.8. L =3D 283 =B5H. https://dl.dropboxusercontent.com/u/19882028/VLF/9%20cores.jpg l/d =3D 96/33 =3D 2.91 So now the effective =B5r is 6.18 L/l =3D 1.75 mH / 96 mm =3D 18.23 mH/m L/l (9) / L/l (5) =3D 1.98 13 core stack: C=3D 202 nF Resonance (with cores) at 6.485 kHz. BW =3D (6.56 - 6.42) kHz =3D 140 Hz. Q= =3D 46. L =3D 2.98 mH https://dl.dropboxusercontent.com/u/19882028/VLF/13cores.jpg Resonance (without cores) at 16.78 kHz. BW =3D (17.26 - 16.38) kHz =3D 880 = Hz. Q =3D 19. L =3D 445 =B5H. l/d =3D 145/33 =3D 4.39 The effective =B5r =3D 6.70 L/l =3D 2.98 mH / 145 mm =3D 20.55 mH/m OK, now, this tends to a certain value for L/l, maybe 22 mH/m (see attachme= nt) for a 0.5mm diameter wire. Hmm, so my coil would be just 35m high, abou= t as high as the feed point of the antenna :-) So a thinner wire is needed or a tube with 3 or more cores in parallel. More soon... 73, Stefan Am 27.04.2016 20:20, schrieb DK7FC: Hi VLF, I've done a quick experiment with the T106-52 cores which could give some m= ore ideas regarding these cores for a compact VLF coil. I wound a coil with 0.5mm enameled cu wire, 85 turns at 33mm diameter. Insi= de the coil there are 5 of these cores stacked on another. In parallel ther= e is a suitable C of 1 uF. https://dl.dropboxusercontent.com/u/19882028/VLF/20160427_195530.jpg The resonance was found at 7.49 kHz. The 3 dB bandwidth is (7.64-7.36) kHz = =3D 280 Hz. Q =3D 27. L =3D 452 uH. Without the cores inside, the resonance frequency rises to 14.54 kHz and th= e bandwidth is (15.12-14.07) kHz =3D 1.05 kHz. Q =3D 14. L =3D 120 uH. Hmm, so in this configuration, the effective =B5r (ur) seems to be just 3.7= 5! :-/ That means i still need half of the number of turns for a single layer VLF = transmit coil?!? 73, Stefan --_000_146187499487861188fyskuleuvenbe_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi Stefan,

 

what about a "fatter" (length/diameter =3D 1) coil filled= with some core stacks in parallel?

For a slim coil (large length/diameter ratio) the inductance is more or = less proportional to the number of windings while for a fat coil inductance= is more or less proportional to the square of the number of windings.

But I don't know how effective the cores will be in such a fat coil.

 

73, Rik  ON7YD - OR7T

 

Van: owner-rsgb_lf_group@= blacksheep.org <owner-rsgb_lf_group@blacksheep.org> namens DK7FC <= selberdenken@posteo.de>
Verzonden: donderdag 28 april 2016 20:34
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: VLF: T106-52 cores on VLF, continued, thoughts...
 
OK, after a break in the sunset i thought:
If =B5r tends to 6.5 and L/l to 22 mH/m for 0.5mm wire for l -> infinity= , and if i want to keep the coil length at 0.8m, which would be 17.6 mH for= 0.5mm wire. However i need 788 mH! So i need a 6.7 times smaller wire, i.e= . 0.074mm diameter. This is impossible and i wouldn't carry the antenna current.
A new coil would only make sense if i can rise the signal by at least 6 dB.= I just measured 260 mA. So let's say 600 mA would be fine. And i like the = 0.4mm wire and would like to use that.
In the moment i see no chance for a single layer coil using this technique = :-(

73, Stefan

Am 28.04.2016 20:02, schrieb DK7FC:
Hmm, well, ok, after some discussions, the show e= hm the experiments must go on.

I'm continuing with a higher l/d ratio. 13 of these cores are available, th= e other ones are parts of my transmit coil now. I like to get 3 measurement= s to approximate a curve showing L/l and =B5r(eff) over the ratio l/d. So a= useful number of cores is 5 (already done, see below), 9 and 13.

5 core stack (yesterdays measurement):
The ratio coil diameter / coil length, l/d =3D 49/33 =3D 1.48.
Effective =B5r =3D 3.75
L/l =3D 452 =B5H / 49 mm =3D 9.22 mH/m

9 core stack:
As a resonance C i use 0.3 uF (measured C =3D 306 nF)
The resonance is at 7.26 kHz. The bandwidth is (7.36 - 7.18) kHz =3D 180 Hz= . Q =3D 40. L =3D 1.75 mH
Without the cores inside, the resonance is found at f =3D 17.1 kHz. BW is (= 17.6 - 16.69) kHz =3D 1.05 kHz. Q =3D 16.8. L =3D 283 =B5H.
https://dl.dropboxusercontent.com/u/1988202= 8/VLF/9%20cores.jpg
l/d =3D 96/33 =3D 2.91
So now the effective =B5r is 6.18
L/l =3D 1.75 mH / 96 mm =3D 18.23 mH/m
L/l (9) / L/l (5) =3D 1.98

13 core stack:
C=3D 202 nF
Resonance (with cores) at 6.485 kHz. BW =3D (6.56 - 6.42) kHz =3D 140 Hz. Q= =3D 46. L =3D 2.98 mH
https://dl.dropboxusercontent.com/u/19882028/= VLF/13cores.jpg
Resonance (without cores) at 16.78 kHz. BW =3D (17.26 - 16.38) kHz =3D 880 = Hz. Q =3D 19. L =3D 445 =B5H.
l/d =3D 145/33 =3D 4.39
The effective =B5r =3D 6.70
L/l =3D 2.98 mH / 145 mm =3D 20.55 mH/m

OK, now, this tends to a certain value for L/l, maybe 22 mH/m (see attachme= nt) for a 0.5mm diameter wire. Hmm, so my coil would be just 35m high, abou= t as high as the feed point of the antenna :-)
So a thinner wire is needed or a tube with 3 or more cores in parallel.
More soon...

73, Stefan


Am 27.04.2016 20:20, schrieb DK7FC:
Hi VLF,

I've done a quick experiment with the T106-52 cores which could give some m= ore ideas regarding these cores for a compact VLF coil.

I wound a coil with 0.5mm enameled cu wire, 85 turns at 33mm diameter. Insi= de the coil there are 5 of these cores stacked on another. In parallel ther= e is a suitable C of 1 uF.
https://dl.dropboxusercontent.com/u/1= 9882028/VLF/20160427_195530.jpg

The resonance was found at 7.49 kHz. The 3 dB bandwidth is (7.64-7.36) kHz = =3D 280 Hz. Q =3D 27. L =3D 452 uH.
Without the cores inside, the resonance frequency rises to 14.54 kHz and th= e bandwidth is (15.12-14.07) kHz =3D 1.05 kHz. Q =3D 14. L =3D 120 uH.

Hmm, so in this configuration, the effective =B5r (ur) seems to be just = 3.75! :-/
That means i still need half of the number of turns for a single layer VLF = transmit coil?!?

73, Stefan

--_000_146187499487861188fyskuleuvenbe_--