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Re: LF: Antenna tuner

To: [email protected]
Subject: Re: LF: Antenna tuner
From: Stefan Schäfer <[email protected]>
Date: Tue, 30 Oct 2012 23:15:13 +0100
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Steinar,

Instead of a HF SWR meter i vote for building a simple RF amperemeter. Resonance <=> peak current (except you're using a class E PA). Works on LF and MF!

73, Stefan


Am 30.10.2012 22:27, schrieb Graham:
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" <[email protected]>
Sent: Tuesday, October 30, 2012 9:03 PM
To: <[email protected]>
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" <[email protected]>
Sent: Tuesday, October 30, 2012 2:09 PM
To: <[email protected]>
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











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