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
|
