Interesting thread...

So a PIC development board with a 20MHZ ceramic resonator may be a problem
with the FCC?   What is the solution?  Put the thing in a metal box?  Are
there tricks to keeping the radiation down such as using chokes, trace
length etc.?  Are metal can crystals less noisy than ceramic
resonators?  What type of device would a stray 20MHZ signal interfere?   Ok
enough with the 20 questions :)

Thanks
- Dan

At 03:01 PM 6/16/02 -0400, you wrote:
>There is no exemption from compliance, the exemption is from formal testing,
>FCC filing and monetary penalties arising from creating the interference.
>
>If one of your products is found to interfere with licensed equipment, the
>user will be required to stop using the device. The FCC will contact you and
>ask about the device. You will have to provide the FCC with enough details
>about the hardware (schematics, etc.) to show that it is in an exempt class.
>Your customer will not be allowed to use the device again until the
>interference is reduced to a level that either satisfies the person who
>filed the complaint or it meets FCC interference levels.
>
>I've gotten the phone call from an FCC field engineer and was relieved that
>the interfering product was one of our exempt devices. If it had been one of
>our non-exempt products we would have been required to contact all our
>customers and tell them to stop using the product until we could provide a
>fix for the interference.
>
>Paul
>
> > -----Original Message-----
> > From: pic microcontroller discussion list
> > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Drew Vassallo
> > Sent: Saturday, June 15, 2002 10:51 PM
> > To: PICLIST@MITVMA.MIT.EDU
> > Subject: [PIC]: FCC exempt!
> >
> >
> > Ok, I've reduced the operating speed of my model airplane monitor
> > down from
> > a 4 MHz crystal to a 1 MHz RC oscillator.  Looks like it works
> > pretty well,
> > except the LED display flickers a LITTLE bit between updates
> > because of the
> > overhead calculations.  No big deal, it's barely perceptible if you're not
> > looking for it.
> >
> > So I gather that this means I'm exempt from FCC compliance, but do I still
> > have to perform any sort of formal testing?  Or do I just wait for the FCC
> > to complain and look into it on their own, only to find out that it's
> > exempt?
> >
> > The only thing I'm at all concerned about is the fact that when I go to a
> > production PCB, the traces will be laid out slightly differently so the
> > capacitance might change the operating frequency.  I suppose I'll have to
> > try it and change the R value at that time.
> >
> > --Andrew
> >
> > _________________________________________________________________
> > Send and receive Hotmail on your mobile device: http://mobile.msn.com
> >
> >
>
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