Message-ID: <5834B15783324F4D986AC1B7DCE23896@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <508FDF4E.7070109@broadpark.no> <508FDF88.8020706@broadpark.no> <500F0ABE29C140E7BA52A38E66D5F7D9@AGB> <50903AA3.1040502@iup.uni-heidelberg.de> <50904097.5060800@broadpark.no>
In-Reply-To: <50904097.5060800@broadpark.no>
Date: Tue, 30 Oct 2012 21:27:30 -0000
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Subject: Re: LF: Antenna tuner
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Depends on how  much  power  you  are  going to  use  .....  50 / 70  watts 
, you  can  get  away  with  a  big  version  of  a  top  band  tuner  , 
parallel  tapped   tuner  .....over  this  voltage  / flashover  becomes  a 
problem for  a  end  fed  Ae  , I use a  top  loading  coil,  seems to  keep 
the  atu  voltage  down ..

Over  that  , you  need  to use a  auto  transformer  and  series  variable 
inductance , luckily  most  normal  HF swr meters  read  at  500  , which 
makes  tuning  a lot  simpler ........but  if  you  cannot  reach  1:1  , 
you  could have  harmonics  , the  swr  meter  , showing the  reflected 
harmonics   from  the  Ae  load   ..

A good  reason to  use  a  wide band   swr  metering system ... band  only 
ones  will  miss out of  band  harmonics

At  gb4fpr  , feeding  200/300  watts  in to  the  600  ft  delta loop, 
there  is  very  little  voltage  in the  tuner

73 -G.

--------------------------------------------------
From: "Steinar Aanesland" <saanes@broadpark.no>
Sent: Tuesday, October 30, 2012 9:03 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: Antenna tuner

> Hi, thanks for the feedbacks from both of you .
>
>
> "Why using such a big monster tuner? Because it is commercial?" Hehe,
> absolutely not Stefan :) but a ham friend of my gave it to me when he
> heard about my 600m transverter project. I will probably take it a part
> an use it for other antenna projects.
>
> I am now planing to make my own variometer, just for the fun of it. I am
> a novice you know , and I have to take the small steps to learn. I came
> across this page describing in easy terms how to make a variometer,
> http://www.giangrandi.ch/electronics/shortanttuner/shortanttuner.shtml .
> It seems not be too difficult :)
>
> LA5VNA Steinar
> loc:JO59jq
> Mal and spam filtering: STRONG
> www.opera.no
>
>
>
>
> Den 30.10.2012 21:37, skrev Stefan Schäfer:
>> Steinar,
>>
>> Graham is right, the coil may be to small for a small amateur antenna.
>>
>> Why using such a big monster tuner? Because it is commercial?
>>
>> We have only 7 kHz of spectrum and assuming "normal" sourrounding
>> losses, you will not even need a variometer part. So it is just a coil,
>> some wire on a PVC tube and a ferrite transformer (or a tap or what you
>> prefer), then cox to the shack.
>>
>> No problem! :-)
>>
>> 73, Stefan
>>
>>
>> Am 30.10.2012 21:24, schrieb Graham:
>>> Steiner
>>>
>>> That looks  a  little   1.6 MHz  ish   to  me  .coils  may  be  not
>>> big enough  .   could  be  the  500  variometer  is missing  from the
>>> space  ?
>>>
>>> could make  a  auto  transformer  , next need a  series  coil of
>>> sorts  , Ae  cap  will  do  the  rest
>>>
>>> G..
>>>
>>> --------------------------------------------------
>>> From: "Steinar Aanesland" <saanes@broadpark.no>
>>> Sent: Tuesday, October 30, 2012 2:09 PM
>>> To: <rsgb_lf_group@blacksheep.org>
>>> Subject: LF: Antenna tuner
>>>
>>>>
>>>> Hi all,
>>>> Is there anyone out there who is familiar with this antenna tuner?
>>>>
>>>> https://dl.dropbox.com/u/16381257/2012-10-29%2023.49.15.jpg
>>>> https://dl.dropbox.com/u/16381257/2012-10-29%2023.49.36.jpg
>>>> https://dl.dropbox.com/u/16381257/2012-10-29%2023.49.50.jpg
>>>> https://dl.dropbox.com/u/16381257/2012-10-29%2023.50.00.jpg
>>>>
>>>> I got it from a HAM friend and will try to use it to tune my 600m
>>>> antenna.  The trouble is that some parts are missing.
>>>>
>>>> -- 
>>>> LA5VNA Steinar
>>>> loc:JO59jq
>>>> Mal and spam filtering: STRONG
>>>> www.opera.no
>>>>
>>>>
>>>>
>>
>>
>>
>
>
>