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[195.171.43.25]) by mx.google.com with ESMTP id tt4si1861266bkb.39.2013.11.08.07.08.55 for ; Fri, 08 Nov 2013 07:08:56 -0800 (PST) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Vendx-0007Bz-QH for rs_out_1@blacksheep.org; Fri, 08 Nov 2013 15:06:41 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Vendx-0007Bq-9W for rsgb_lf_group@blacksheep.org; Fri, 08 Nov 2013 15:06:41 +0000 Received: from rhcavuit01.kulnet.kuleuven.be ([134.58.240.129] helo=cavuit01.kulnet.kuleuven.be) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1Vendv-0001WB-5I for rsgb_lf_group@blacksheep.org; Fri, 08 Nov 2013 15:06:40 +0000 X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-KULeuven-Scanned: Found to be clean X-KULeuven-ID: ED8AA1380B5.A3BCA 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 cavuit01.kulnet.kuleuven.be (Postfix) with ESMTP id ED8AA1380B5 for ; Fri, 8 Nov 2013 16:06:35 +0100 (CET) Received: from ICTS-S-HUB1.luna.kuleuven.be (icts-s-hub1.luna.kuleuven.be [10.112.9.15]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by icts-p-smtps-2.cc.kuleuven.be (Postfix) with ESMTPS id E916620041 for ; Fri, 8 Nov 2013 16:06:35 +0100 (CET) Received: from ICTS-S-MBX1.luna.kuleuven.be ([fe80::edaf:341f:90e:f70e]) by ICTS-S-HUB1.luna.kuleuven.be ([fe80::f5f7:d8cc:bee0:28d3%26]) with mapi id 14.03.0158.001; Fri, 8 Nov 2013 16:06:35 +0100 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Thread-Topic: LF: remote antenna tuning Thread-Index: AQHO3HCUCD1oahz2q0ikAFZZ4yK07pobS52AgAASlqA= Date: Fri, 8 Nov 2013 15:06:35 +0000 Message-ID: <7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037@ICTS-S-MBX1.luna.kuleuven.be> References: <7E7DFBB4D102A04DB5ADC88D66628A4A0FC908D5@ICTS-S-MBX2.luna.kuleuven.be>,<527CEE11.8070509@iup.uni-heidelberg.de> In-Reply-To: <527CEE11.8070509@iup.uni-heidelberg.de> Accept-Language: nl-BE, en-GB, en-US Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.112.13.14] MIME-Version: 1.0 X-HELO-Warning: Remote host 134.58.240.129 (rhcavuit01.kulnet.kuleuven.be) used invalid HELO/EHLO cavuit01.kulnet.kuleuven.be - verification failed X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Stefan, remote tuning of the loading should be done by optimizing SWR (at the TX), not for maximum RF current. If one keeps that in mind there is no problem. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [134.58.240.129 listed in list.dnswl.org] -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 54f9a9b24d9d5f31a632377c3b90b222 Subject: RE: LF: remote antenna tuning Content-Type: multipart/alternative; boundary="_000_7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037ICTSSMBX1lunaku_" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=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 Status: O X-Status: X-Keywords: X-UID: 1754 --_000_7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037ICTSSMBX1lunaku_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Stefan, remote tuning of the loading should be done by optimizing SWR (at the TX), = not for maximum RF current. If one keeps that in mind there is no problem. I am not sure if I will keep the remote variometer tuning. It needs some ex= tra wires to the loading coil and I am not sure how long the small DC motor= will function properly with all the rain and frost coming up. Maybe I will change to a "classic" ATU (PI-filter version). Has anyone expe= rience with that? Some fast math tells me that the 2 caps need to be 0-4nF and the coil 0-15u= H. 73, Rik ON7YD ________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org= ] namens Stefan Sch=E4fer [Stefan.Schaefer@iup.uni-heidelberg.de] Verzonden: vrijdag 8 november 2013 14:58 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: LF: remote antenna tuning Hi Rik, Thanks for sharing your experiences. I also didnt expect that this effect is so noticable. What do you plan to do now? I am using a current transformer at the cold end of the loading coil and ha= ve a small analog meter to show the current (peak). And my antenna even nee= ds a re-tuning when QSYing from CW to WSPR... How do you match the coil to the cable? Directly, a tap or a ferrite transf= ormer? Am 08.11.2013 14:03, schrieb Rik Strobbe: By the way: remote tuning can be done correctly by tuning for best SWR ins= tead of highest RF current at the TX output. 73, Rik ON7YD - OR7T I think the best is to accurately match the feedpoint impedance (at resonan= ce Z=3DR+j0) of the antenna to 50 Ohm, by using a ferrite transformer. Then= the variometer position of best SWR is the best working point for the PA (= and the LPF). Highest RF current at TX output can quickly destroy the PA, e= specially class-E types :-) 73, Stefan/DK7FC --_000_7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037ICTSSMBX1lunaku_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi Stefan,

 

remote tuning of the loading should<= a> be done by optimizing SWR (at the TX), not for maxim= um RF current.

If one keeps that in min= d there is no problem.

I am not sure if I = will keep the remote variometer tuning. It needs some extra wires to the loading coil and I am not=  sure how long the small DC motor will function<= a> properly with all the rain and&n= bsp;frost coming up.

Maybe I will change to a "class= ic" ATU (PI-filter version). Has anyone=  experience with that?

Some fast math tells me = that the 2 caps need to be 0-4nF= and the coil 0-15uH.

 

73, Rik  ON7YD

 

Van: owner-rsgb_lf_group@blacksheep.org [o= wner-rsgb_lf_group@blacksheep.org] namens Stefan Sch=E4fer [Stefan.Schaefer= @iup.uni-heidelberg.de]
Verzonden: vrijdag 8 november 2013 14:58
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: remote antenna tuning

Hi Rik,

Thanks for sharing your experiences.
I also didnt expect that this effect is so noticable.
What do you plan to do now?
I am using a current transformer at the cold end of the loading coil and ha= ve a small analog meter to show the current (peak). And my antenna even nee= ds a re-tuning when QSYing from CW to WSPR...
How do you match the coil to the cable? Directly, a tap or a ferrite transf= ormer?

Am 08.11.2013 14:03, schrieb Rik Strobbe:

 By the way: remote tuning can be don= e correctly by tuning for best SWR instead of=  highest RF current at the TX output.

 

73, Rik  ON7YD - OR7T


I think the best is to accurately match the feedpoint impedance (at resonan= ce Z=3DR+j0) of the antenna to 50 Ohm, by using a ferrite transformer. = Then the variometer position of best SWR is the best working point for the = PA (and the LPF). Highest RF current at TX output can quickly destroy the PA, especially class-E types :-)

73, Stefan/DK7FC

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