Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id wB3JVIFm022341 for ; Mon, 3 Dec 2018 20:31:19 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1gTtrm-0005Od-33 for rs_out_1@blacksheep.org; Mon, 03 Dec 2018 19:26:50 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1gTtri-0005OU-BM for rsgb_lf_group@blacksheep.org; Mon, 03 Dec 2018 19:26:46 +0000 Received: from sonic305-20.consmr.mail.ir2.yahoo.com ([77.238.177.82]) by relay1.thorcom.net with esmtp (Exim 4.91_59-0488984) (envelope-from ) id 1gTtrg-00046B-JL for rsgb_lf_group@blacksheep.org; Mon, 03 Dec 2018 19:26:45 +0000 X-DKIM-Result: Domain=yahoo.co.uk Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s2048; t=1543865203; bh=MliCF83P5rSuvS7SYbwaE22Zf70nCU/iSUBJ4+voF0k=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=FKfwVP1CgPBvEEKQLXIDh4GhdGyiYHzNmTFHDs2fDV0RXYDwat0lECsdEXUboS+xfztquhi32+XizozvUicuOjJJ3BL/Kg2uMqda/kCD2XdpuTwgS6APfCLqrigiuPiU4bUv14qRTenyBo5D+8TYLCeLYL1dQnyq5zBXzOFnF8e+JFpAyY1+KZHrNeMO7uLBqxj9o3DoUImVk4h19W8H2Wox1z0pz6OoZ5VQyBGuggh84a3+UXl1vJ9tzS8crT65pcrHiOR/6jp9y9PjtEtgLTU7kDheSlI4TplLwiNaSCAy9jj5hvp52sr8vI/88xvyLSSJTfnaYqoV4+sxliisIQ== X-YMail-OSG: zp9502gVM1l81HDpzR9itIv2H2PcboDOwbTCXucDDiEQo9Nb_SUfjlF7fi3ctS. y5VdqtdREjY3KfxRvmBEprtWyH2DMv2Tk3_kY9QABEP6AnTVv1Pnl0yMgP4iNrkl1_jHRcXCXtdr f2M3fofGIPC.6SUCiWDiSCZ7mXwQfbfCrSJiCqXC7IZxpWA7e7GpOJlviF17ObfsJIG5QDmw3J1t 07HLrQjJ9kAi2Ou3_jv2w1qHc_Gn3TSKXpn9WSnAl2Y.DJhDwOpBhuNbOJPiXs1B5x4eg7ihCu72 1gqseYFRcpFg7VwTnEsGdrJMiivf_GWS85TM1DZsl2JHBqvL4Oza65DJPkt_acnVVIq8VkpeFsA. m5Hx8dMaUq.8AKZ5Vo4WcR7ge6yYg6V5NoNyaxhhvuaUp5saAJU.6.mk565GYZaD9up36zSyF2jm Cl6eCkC7TOjm61oPFPUikyu.CkJMSe2ivcZLHgPl_CQazULivqIrTg2XeoTDLydaasCyVHdRdQ62 i5D7PzZci4du7Qj7hyIczUzUBR6d2Wc8sNdVjobfyDXWYNgeZjQAOirNjXSRH7_CkMHNKXV0.Fiu 4jwuTA_jlVlt2ReKoVVmmi3SPZXJb_H423OpKUjDhDhZoDFQU6WoezvjRmcsXaWzvSp.YsKk379E xmFAQr5nGhf27Ro1AmHfUGbUSuj7z.1TnwSd1c7Hl4xuRqMQ2ia1z5XA3oiKVLjjhiYseAxg4ehN _rXYuXZG01rnsHpbNmYN7wE7VR7Z_VuGlgVS4QeijR2u9DoNJ_v7wZJnutJFBnrqfoikxBXxI7Lx YmNg0NDrsC5RxQh3gNaRbZMeRPzO.VxGmyVQd71o2L2Y6pMEXgZy0bgKQVZjLgXd9Q7AoAHU2b50 oMLY1pocQB6at1s19o7ZUmKVfLsZf5aeMh1p0.RTYX1nmpbdrGFiKTb4m62r103ucOVldAcCTkwF bFE4X5g0EXX5qnBN0Ctnf2a2Vx_AR4SteRmK3QcKFH0rl2K.fkYeqadzBCXFMu25HQc02hEdkKd1 K5GwIUg-- Received: from sonic.gate.mail.ne1.yahoo.com by sonic305.consmr.mail.ir2.yahoo.com with HTTP; Mon, 3 Dec 2018 19:26:43 +0000 Date: Mon, 3 Dec 2018 19:26:07 +0000 (UTC) From: David Hine To: "rsgb_lf_group@blacksheep.org" Message-ID: <617616470.2082575.1543865167792@mail.yahoo.com> In-Reply-To: References: <0d2ac752-44f5-e503-e2a0-a8b4c841bcee@n1bug.com> <5C052984.8030902@posteo.de> <04207F3E-523E-40B8-A93C-E1AEBE0D3A4A@md.metrocast.net> <3c05b896-ecf2-8b93-b6e7-e618fa7263c3@n1bug.com> MIME-Version: 1.0 X-Mailer: WebService/1.1.12827 YahooMailNeo Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.140 Safari/537.36 Edge/17.17134 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: I worked with large VLF transmitters, and dampness caused leakages on the antenna and in the ATU room will affect the tuning. When you said that this changes when the antenna is used shows this is the [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [77.238.177.82 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (evad_hine[at]yahoo.co.uk) 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) [77.238.177.82 listed in wl.mailspike.net] 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-Scan-Signature: fce77e88417377663dedf94f027ec622 Subject: Re: LF: Re: More on unstable antenna R Content-Type: multipart/alternative; boundary="----=_Part_2082574_2044993383.1543865167790" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: *** X-Spam-Status: No, hits=3.5 required=5.0 tests=FORGED_MUA_MOZILLA,HTML_30_40, HTML_MESSAGE,TO_ADDRESS_EQ_REAL 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 ------=_Part_2082574_2044993383.1543865167790 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I worked with large VLF transmitters, and dampness caused leakages on the a= ntenna and in the ATU room will affect the tuning. When you said that this = changes when the antenna is used shows this is the likely cause. The sharpe= r the tuning, the worse this becomes, David Hine From: Rob Renoud To: rsgb_lf_group@blacksheep.org=20 Sent: Monday, 3 December 2018, 19:16 Subject: LF: Re: More on unstable antenna R =20 Hi Paul, Thanks for the info regarding your measurements. I believe you use a ScopeMatch in the shack to make your tuning adjustments= =20 and voltage/current measurements. I also run a ScopeMatch on LF and MF that= =20 uses a capacitor voltage divider and toroid current sensor.=C2=A0 I have fo= und=20 the ScopeMatch to be an excellent tool for visually tuning the matching coi= l=20 to resonance and R=3D50 ohms as well as monitoring for changes during the= =20 operating period.=C2=A0 I have found, however, that the SceopeMatch is not= =20 particularly accurate for determining actual SWR or input impedance (R=20 and/or X) based on voltage and current measurements using that tool when=20 compared to a know accurate VNA. Wonder if you might have access to an antenna analyzer or VNA to measure th= e=20 changes that you are experiencing?=C2=A0 Think that approach might be more = useful=20 in identifying where to look. Like you, I also have significant winter to summer changes in the antenna= =20 values that are handled by the tuner.=C2=A0 I have not experienced any chan= ges=20 during the transmitting period, however, so am scratching my head with=20 you.... Regards, Rob - K3RWR -----Original Message-----=20 From: N1BUG Sent: Monday, December 03, 2018 5:54 PM To: rsgb_lf_group@blacksheep.org Subject: Re: LF: More on unstable antenna R On 12/3/18 12:22 PM, N1BUG wrote: > At the time of the tests in question, R at the transmitter end of > the line varied from 58 ohms at the start of a transmission to 46 > ohms 2 minutes later. I calculated that from measured voltage and/or > current on a 50 ohm line with no reactance. Uh... not quite. Let's try that again! Measure voltage, measure current (I measured peak on the scope and converted to RMS) Calculate R =3D E/I I am assuming that works as long as X =3D 0. Voltage and current waveforms were exactly in phase for all measurements. Correct me if I have gone wrong here. I can always go wrong with math. 73, Paul=20 =20 ------=_Part_2082574_2044993383.1543865167790 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I worked with = large VLF transmitters, and dampness caused leakages on the antenna and in = the ATU room will affect the tuning. When you said that this changes when t= he antenna is used shows this is the likely cause. The sharper the tuning, = the worse this becomes, David Hine


=
From: Rob Renoud <k3rwr@md.metr= ocast.net>
To: rsgb= _lf_group@blacksheep.org
Sent: Monday, 3 December 2018, 19:16
Subject: LF: Re: More on unstable antenna R
 =

Hi Paul,

Thanks for the info regarding your measurements.

I believe you use a ScopeMatch in= the shack to make your tuning adjustments
and voltage/current measurements. I = also run a ScopeMatch on LF and MF that
uses a capacitor voltage divider and to= roid current sensor.  I have found
the Scop= eMatch to be an excellent tool for visually tuning the matching coil
to resonan= ce and R=3D50 ohms as well as monitoring for changes during the
<= div dir=3D"ltr">operating period.  I have found, however, that the Sce= opeMatch is not
particularly accurate for determining actual SWR or input imped= ance (R
and/or X) based on voltage and current m= easurements using that tool when
compared to a k= now accurate VNA.

Wond= er if you might have access to an antenna analyzer or VNA to measure the
changes that you are experiencing?  Think tha= t approach might be more useful
in identifying w= here to look.

Like you= , I also have significant winter to summer changes in the antenna
values that are handled by the tuner.  I have not ex= perienced any changes
during the transmitting pe= riod, however, so am scratching my head with
you= ....

Regards,
Rob - K3RWR


-----Original Message-----
From: N1BUG
Sent: Monday, December= 03, 2018 5:54 PM
Subject: Re: LF: More = on unstable antenna R

= On 12/3/18 12:22 PM, N1BUG wrote:
> At the tim= e of the tests in question, R at the transmitter end of
> the line varied from 58 ohms at the start of a transmission t= o 46
> ohms 2 minutes later. I calculated that= from measured voltage and/or
> current on a 5= 0 ohm line with no reactance.
Uh... not quite. Le= t's try that again!

Me= asure voltage, measure current
(I measured peak o= n the scope and converted to RMS)
Calculate R =3D= E/I

I am assuming tha= t works as long as X =3D 0. Voltage and current
w= aveforms were exactly in phase for all measurements.

Correct me if I have gone wrong here. I can = always go wrong with math.

73,
Paul




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