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Re: LF: Re: Should I be aiming for a better match than this?

To: Alan Melia <[email protected]>
Subject: Re: LF: Re: Should I be aiming for a better match than this?
From: Chris Wilson <[email protected]>
Date: Wed, 14 Oct 2015 12:33:07 +0100
In-reply-to: <43464DACBFAA49C08A73FB93FFF52105@gnat>
Organization: Gatesgarth Developments
References: <[email protected]> <43464DACBFAA49C08A73FB93FFF52105@gnat>
Reply-to: [email protected]
Sender: [email protected]
Hello Alan,

Tuesday, October 13, 2015


>>>can i work out the antenna current from this?
> Not really this is the current in the coax. If the current and voltage are
> not in phase then by definition you have reactance in the coax termination.
> You should try adjusting the variometer for current and voltage in phase
> (that is resonance) , then adjust the turns ratio on the transformer to
> match the resultant aerial resistive component to the 50ohm coax (if 
> possible :-))  ) That should give you optimum performance.

> The reactive load may be what is tripping the protection it will give bigger
> voltages(or currents) than the matched condition.

> Whilst you have been getting a signal out, I suggest the next experiment is
> to try and reducethe ground loss before you spend a lot of time getting a
> perfect match to an imperfect aerial system (only to have to do it all again
> when you manage to get the ground loss down.)

> Alan
> G3NYK

Thanks  Alan, appreciated as always. I may be doing something wrong as
I  can't  seem to get the phase right, I will try later when my pal is
free  again.  When he  turning the variometer coil either way even by
tiny  amounts  the  phasing  seems to go either side of matched, but I
couldn't  see  a perfect match on the scope, which seems rather odd. I
intend  to try reducing ground losses, but it must be done discreetly,
the  wife  gets worried when she sees me carrying large coils of wire
into  "her"  garden ;) She talks of the place looking like GCHQ... Now
what's wrong with that? ;)






-- 
Best regards,
 Chris                            mailto:[email protected]


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