Tuned circuit

• To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
• Subject: Tuned circuit
• From: Tesla List <tesla-at-stic-dot-net>
• Date: Mon, 22 Sep 1997 05:00:56 -0500
• Approved: tesla-at-stic-dot-net

From: 	Phil Chalk[SMTP:philoc-at-ozemail-dot-com.au]
Sent: 	Monday, September 22, 1997 2:52 AM
To: 	Tesla List
Subject: 	Re: Tuned circuit

Tesla List wrote:

> From:   Edward V. Phillips[SMTP:ed-at-alumni.caltech.edu]
> Sent:   Sunday, September 21, 1997 12:49 PM
> To:     tesla-at-pupman-dot-com
> Subject:        Re:  Tesla not Marconi
>
> "The resonant tuned circuit allowed receivers to essentially amplify
> the received signal to a useable level. Useable even without tubes or
> transistors. Pretty neat stuff!!!"
>         A resonant circuit CAN'T amplify a signal at all!  It can be
> used for impedance matching, however.
> Ed

Ed,

Granted, a resonant circuit can't amplify, as such.  However,
relatively, it can give that impression.
As a seasoned crystal-set builder from way back, I have had (soft)
loudspeaker volume from crystal sets, using no other power than what
comes down the aerial wire.
The parallel tuned circuit up the front-end, due to it's very high
impedance at resonance, gives you (sort of) an amplified version of the
signal you're after from the cacophony of noise present at the aerial.
Yes, it's still _not_ amplification per se, but has a similar efect in
the headphones.

Come to think of it, though there's clearly no _power_ amplification
going on, the tuned circuit (in a crystal Rx) _effectively_ gives you
_voltage_ amplification.

Regards,

Phil Chalk.

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