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Date: Fri, 08 Nov 2013 18:40:10 +0000
From: pat <g4gvw@aol.com>
Organization: G4GVW
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References: <7E7DFBB4D102A04DB5ADC88D66628A4A0FC908D5@ICTS-S-MBX2.luna.kuleuven.be>,<527CEE11.8070509@iup.uni-heidelberg.de> <7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037@ICTS-S-MBX1.luna.kuleuven.be> <527D0CCB.6090208@iup.uni-heidelberg.de>
In-Reply-To: <527D0CCB.6090208@iup.uni-heidelberg.de>
Subject: Re: LF: remote antenna tuning
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Hi All,

A suggestion: battery operated tuning device at antenna end and=20
"wireless" link back to shack. Wireless can operate at a non-interfering=20
frequncy (HF/VHF/UHF/Optical).

73


On 08/11/13 16:09, Stefan Sch=E4fer wrote:
> Hi Rik,
>
> Am 08.11.2013 16:06, schrieb Rik Strobbe:
>>
>> Hi Stefan,
>>
>> remote tuning of the loading should be done by optimizing SWR (at the=20
>> TX), not for maximum RF current.
>>
>> If one keeps that in mind there is no problem.
>>
> ...which is in agreement with what i said.
> But once you have matched your antenna to 50 Ohm on resonance and you=20
> can only vary the reactive part of the antennas impedance (after doing=20
> QSY), then you will get the maximum antenna current at best SWR=20
> (assuming that Rrad+Rloss is constant which is not to far from reality)=
.
>
>> I am not sure if I will keep the remote variometer=20
>> tuning. It needs some extra wires to the loading coil and=20
>> I am not sure how long the small DC motor will function properly with=20
>> all the rain and frost coming up.
>>
> Here it holds since more than 2 years for LF now..
>
> 73, Stefan
>


--=20
73 de pat g4gvw
es gd dx
qth nr Felixstowe
East Coast UK


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    <div class="moz-cite-prefix">Hi All,<br>
      <br>
      A suggestion: battery operated tuning device at antenna end and
      "wireless" link back to shack. Wireless can operate at a
      non-interfering frequncy (HF/VHF/UHF/Optical).<br>
      <br>
      73<br>
      <br>
      <br>
      <br>
      <br>
      <br>
      <br>
      On 08/11/13 16:09, Stefan Sch&auml;fer wrote:<br>
    </div>
    <blockquote cite="mid:527D0CCB.6090208@iup.uni-heidelberg.de"
      type="cite">
      <meta content="text/html; charset=ISO-8859-1"
        http-equiv="Content-Type">
      Hi Rik,<br>
      <br>
      Am 08.11.2013 16:06, schrieb Rik Strobbe:
      <blockquote
cite="mid:7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037@ICTS-S-MBX1.luna.kuleuven.be"
        type="cite">
        <meta http-equiv="Content-Type" content="text/html;
          charset=ISO-8859-1">
        <div style="direction: ltr; font-family: Tahoma; color: rgb(0,
          0, 0); font-size: 10pt;">
          <p>Hi&nbsp;Stefan,</p>
          <p>&nbsp;</p>
          <p>remote&nbsp;tuning of
            the&nbsp;loading&nbsp;should&nbsp;be&nbsp;done&nbsp;by&nbsp;optimizing&nbsp;SWR (at
            the TX),&nbsp;not&nbsp;for maximum&nbsp;RF current.</p>
          <p>If&nbsp;one&nbsp;keeps&nbsp;that in&nbsp;mind&nbsp;there is&nbsp;no problem.</p>
        </div>
      </blockquote>
      ...which is in agreement with what i said.<br>
      But once you have matched your antenna to 50 Ohm on resonance and
      you
      can only vary the reactive part of the antennas impedance (after
      doing
      QSY), then you will get the maximum antenna current at best SWR
      (assuming that Rrad+Rloss is constant which is not to far from
      reality).<br>
      <br>
      <blockquote
cite="mid:7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037@ICTS-S-MBX1.luna.kuleuven.be"
        type="cite">
        <div style="direction: ltr; font-family: Tahoma; color: rgb(0,
          0, 0); font-size: 10pt;">
          <p>I&nbsp;am&nbsp;not&nbsp;sure&nbsp;if I&nbsp;will keep the&nbsp;remote&nbsp;variometer
            tuning.&nbsp;It&nbsp;needs&nbsp;some
            extra&nbsp;wires to the&nbsp;loading&nbsp;coil and I&nbsp;am&nbsp;not&nbsp;sure&nbsp;how long
            the&nbsp;small&nbsp;DC
            motor&nbsp;will&nbsp;function&nbsp;properly&nbsp;with all the&nbsp;rain and&nbsp;frost
            coming up.</p>
        </div>
      </blockquote>
      Here it holds since more than 2 years for LF now..<br>
      <br>
      73, Stefan<br>
      <br>
      <blockquote
cite="mid:7E7DFBB4D102A04DB5ADC88D66628A4A0FC98037@ICTS-S-MBX1.luna.kuleuven.be"
        type="cite">
        <div style="direction: ltr; font-family: Tahoma; color: rgb(0,
          0, 0); font-size: 10pt;"> </div>
      </blockquote>
    </blockquote>
    <br>
    <br>
    <pre class="moz-signature" cols="72">-- 
73 de pat g4gvw
es gd dx
qth nr Felixstowe
East Coast UK</pre>
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