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Re: [Amps] *** SPAM *** Re: Antenna traps

To: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Subject: Re: [Amps] *** SPAM *** Re: Antenna traps
From: Steve Thompson <g8gsq@eltac.co.uk>
Date: Fri, 16 Dec 2005 15:27:05 +0000
List-post: <mailto:amps@contesting.com>

Ian White GM3SEK wrote:

> 
> Let's think of two totally generalized impedances, (R1 in series with 
> jX1) and (R2 in series with X2). In this context X1 and X2 can have 
> either sign.
> 
> Now add series elements -X1 and -X2 to cancel both reactances out. We 
> now have resistive impedances R1 and R2, which can be matched with the 
> minimum-Q solution using two elements in one of the L-network 
> configurations.
This is where I started - but you can always add a first element to take 
you to a pure resistance that's nearer your target than (say) R1 is. 
Then, the L match from the new resistance to target will have a lower Q 
than the one from R1 to target and the three elements give you lower Q 
than two.

I think the train of thought can be valid where you can't choose 
whichever of the L match permutations is needed for minimum Q - that's 
the trap I fell in to.

Steve
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