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Message-ID: <527D3331.7080109@iup.uni-heidelberg.de>
Date: Fri, 08 Nov 2013 19:53:37 +0100
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
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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> <527D300A.7000909@aol.com>
In-Reply-To: <527D300A.7000909@aol.com>
Subject: Re: LF: remote antenna tuning
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Oh yes, or, a phase meter (M0BMU) and a battery operated variometer=20
motor. Without an additional cable to the shack. Then the SWR meter in=20
the shack confirms that everything is fine.

73, Stefan

Am 08.11.2013 19:40, schrieb pat:
> Hi All,
>
> A suggestion: battery operated tuning device at antenna end and=20
> "wireless" link back to shack. Wireless can operate at a=20
> non-interfering 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=20
>>> the 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=20
>> doing 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=20
>>> motor will function properly with 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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Oh yes, or, a phase meter (M0BMU) and a battery operated variometer
motor. Without an additional cable to the shack. Then the SWR meter in
the shack confirms that everything is fine.<br>
<br>
73, Stefan<br>
<br>
Am 08.11.2013 19:40, schrieb pat:
<blockquote cite="mid:527D300A.7000909@aol.com" type="cite">
  <meta content="text/html; charset=ISO-8859-1"
 http-equiv="Content-Type">
  <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>
</blockquote>
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