Message-ID: <56768741.3010603@posteo.de>
Date: Sun, 20 Dec 2015 11:47:29 +0100
From: DK7FC <selberdenken@posteo.de>
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References: <1452799271.20151208165824@chriswilson.tv> <566714E9.2040107@posteo.de> <927353708.20151219112829@chriswilson.tv>
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Subject: Re: LF: Variometer question
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Hi Chris,

Am 19.12.2015 12:28, schrieb Chris Wilson:
> Christmas last minute work and home jobs have got in the way.
Same here. There are always open projects :-)

>   It's
> electrically and mechanically complete and working save for the
> microswitch end stops, which I rushed and in the light of day was
> relegated to the bin :) I will redo these in a more elegant manner!
>    
Uuh, so something must have been wrong connected?!

> Is there any hope the variometer could be in the shack at the amp end
> of the co-ax feed to the loading coil?
Yes this is possible too and has been done by some in the past. But it 
is not the best choice to match the system. There can be significantly 
higher losses. Also the voltages across the coax cable can be very high, 
depending on the reactance that you want to compensate.
We are talking about LF, don't we?!
Also you cannot use a transformer any more between coax and loading coil 
because it will saturate at higher voltages...
You can use that method for a fine-fine-tuning if you want to have an 
SWR of 1:1.00000000000000000000000000000000000000000 but it's not a good 
choice to tune a narrow band antenna from 137.7 to 136.17, for example.

> Thanks for your help Stefan, and a happy Christmas and a healthy and
> prosperous New Year, I have to say I am disappointed you haven't put
> an angel at the top of "your" tree ;) All the best I am always amazed
> at your ingenuity and courage in the woods, take care.
Maybe i can find an angle before xmas is starting. But we have +16 °C 
here these days.
What i thought i could do up there in the tree is a nice breakfast with 
some coffee! :-)
When is the time for teatime in UK? And do you really ALL have teatime 
to that time there? ;-) Probably not. Same like here, we are not at all 
eating Sauerkraut all the time :-)

73, Stefan