[Fwd: recording of signal strength???]

[Andre' Kesteloot]

An excellent point by John N4NUN
Andre'
********************************************
Teller.John@orbital.com wrote:

> Actually the paddle/joystick inputs on the PC are not connected to an ADC
> at all.  The potentiometers on the joystick each form the R of an RC
> circuit used as a timing source for 1/4 of a 558 (a quad 555).  This
> outputs a pulse train which is counted by the PC software (no hardware
> counter, just an input bit).  Very crude, but very, very cheap!
>
> --- John.
>
> "Andre' Kesteloot" <akestelo@bellatlantic.net> on 03/26/99 11:02:42 PM
>
>
>
>  To:      mskelly@capaccess.org
>
>  cc:      AMRAD Tacos <tacos@amrad.org>,
>           "rsgb_lf_group@blacksheep.org"
>           <rsgb_lf_group@blacksheep.org>(bcc: John
>           Teller/ORBVA)
>
>
>
>  Subject: Re: recording of signal strength???
>
>
> God point to keep in mind.
> Thanks Michael, for the reminder of days gone by (the game input of the
> IBM design)
> 73
> Andre'
> *******************************************
> Michael F. Skelly wrote:
>
> > If you only need 8-bit resolution, you might consider the game
> > paddle inputs.  Frequently they consist of 5V, ground, and a
> > potentiometer wiper, and the paddle itself is just a variable
> > resistor.  Linearity is not very good, and timing is not very
> > good, but you don't need that to record band activity.  The A/D
> > conversion function of the game paddles is never any high
> > frequency sample/hold function, so don't expect to record anything
> > more than 200 Hz.
> >
> > -KA8OPJ