At 20:28 2007-03-22, you wrote:
>Klas Strandberg wrote:
>
> >I often buy an IC which has been released on the market. I read the
> >data.sheet and it's mostly very accurate.
> >But it is not until I start working with the IC, that I discover
> >it's limitations and partly awkward characteristics! The designer
> >who plots the entire PCB with a computer, he never discovers that.
> >I believe that the Samson people had planned to make a more expensive
> >recorder. It has four tracks, balanced and fairly good inputs, a
> >clean phantom power and surprisingly low noise internal cardioids.
> >(Not good enough for naturesound, though) But they never discovered
> >the error with the 600 Hz tone until it was too late. The production
> >was already going behind the point of no return.
> >
> >
> I have to admit I don't understand this.Wouldn't a working prototype
>have this problem? It happens during normal use. Sure, components can be
>tricky (let me tell you some day about building an electronic organ in
>the 60s) but to go into production without having tested several
>prototypes (to weed out components with +/- specs to see if some were
>outside the requirements of the circuit) seems pretty terrible to me.
It IS terrible! That is what I am trying to say.
And every electronic builder (you, too??) knows that a prototype
design may look like a birdnest at the bench, but work fine. (Except
induced hum) Then you make a nice PC board and box and all, and you
get rid of the induced hum, but instead you hear a radio station
which is impossible to get rid of...
RF disturbancies is about the same as crappy phantom power. Have I
made a preamp which picks up RF-noise, I trow it away. There is no
use in trying to redesign it and add coils and such things. Every
transistor has a PN transition, which is a diod. And every diod may
act as a detector, making HF audible. Going into it and try to solve
problems is mostly a waist of time.
You may get rid of the RF noise you hear with the device at your
bench, but then you get some other RF noise when you use it somewhere else.
Life is terrible, I keep on saying that all the time, haha.
(PS: I would love to hear about your organ project! Off list. Was it
the one described in Popular Electronics?)
Klas
>
>=3D=3D=3D=3D=3D=3D=3D=3D
>Chuck Bragg, Pacific Palisades, CA
>Membership, Newsletter, Web manager
>Santa Monica Bay Audubon Society
>www.smbas.org
>=3D=3D=3D=3D=3D=3D=3D=3D
>
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email:
website: www.telinga.com
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