PSN-L Email List Message

Subject: Re: My first Sensor
From: "tchannel" tchannel@..............
Date: Thu, 21 Sep 2006 07:06:48 -0600

Hi, I am making my own amp and filter, what would you suggest for Gain, and 
lowpass Hz?
Thanks, Ted
----- Original Message ----- 
From: "Geoffrey" 
Sent: Thursday, September 21, 2006 12:03 AM
Subject: Re: My first Sensor

> Hello Ted;
> The only thing I can add is that
> below Frq:1Hz or Per:1Sec You usually use
> Period which is seconds and above that
> you use Hertz. You get an infinite range
> between 1 and zero for period and
> 1 and infinity for CPS. But if you want
> to do filter calculations I find using
> only HZ works just fine. Use a calculator like
> the TI 36X Solar or whatever programs
> to help you with the filters. I can recommend
> a filter ARRL filter program as well as
> as LT Spice which are both free, or used to be,
> also a spectra program to analyze your noise/filters.
> ! Hz or !sec is a kind of natural division point
> between two worlds so to keep from getting
> confused just use Hz if you do any calcs.
> The formulas work quite well provided you
> have the decimal places to work with (10 or more).
> Do not round any intermediate calcs until you
> get your final answers.
> If your system is set up right then damping is probably
> your troubles. But any motion you can see
> with the naked eye should send your signal
> into saruration and cutoff (clipping)
> making a square wave. Overdriving the amplifier
> makes good to get first time of arrival
> but you cant really see anything else.
> I read where Robert Kennedy Played games
> with Mr. President (Johnson) not long before
> he (R.Kennedy) was Assassinated by placing a
> (assumed) ultra-sonic mechinism into a brief case
> and holding it on his lap so no recording could
> be made. I thing the mechanism he used
> Jammed the microphones in the room
> driving the preamp into a square wave
> essentially deafining the recorders.
> This upset the secret service to no end.
> Or so i read. This was back in the Early 1960s.
> The time of the Buffalo Springfield song
> called "For What Its Worth"
> Your system should be so sensitive
> just blowing on it should drive it into
> clipping.
> Good Luck.
> Regards;
> geoff
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