Re: Compact Fluorescent Noise

["Jeff Volp" <JeffVolp@xxxxxxx>]

Hi Dave,

(answering both posts)

Yes, a digital scope would be nice, but this is my old friend Tektronix 7603
that I used for 30 years.  I bought it when I left the lab.  They were
probably happy they didn't have to calibrate it anymore.

The XTB-II bandpass filter is not high-Q to prevent too much ringing, but it
does attenuate out-of-band signals.  What I think is happening is that the
high-frequency chopper in the CF bulb varies its frequency over each half
cycle, and it enters the X10/Insteon passband as the voltage approaches
zero.  Higher frequency noise in the middle of each half cycle would have
been rejected by the XTB-II bandpass filter.  I'll try to take a look at it
with just a high-pass filter to knock out the 60Hz.

Thanks for the pointer to your info on the CM15A AGC.

Jeff
"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
news:4548cbd6.253352156@xxxxxxxxxxxxxxxx
> "Jeff Volp" <JeffVolp@xxxxxxx> wrote:
>
> >Sorry about the typos.  I swear they weren't there when I proofread that.
> >It must be that CF noise...
> >
> >I forgot to point out my friend the transient right smack in the middle
of
> >the center X10 reception window.
> >
> >This signal was monitored after the bandpass filter in the XTB-II.  So
this
> >is what is sent on to the envelope detector.
> >
> >Jeff
> >
>
> Your postscript and my questions crossed in the ether. I should have
> realized you were relying on the XTB passband when discussing the
frequency
> content. It would be interesting to see the noise through a wider passband
> such as through the scope adapter circuit shown in Appendix C (Figure C-3)
> of Microchip's AN236.
>
> http://davehouston.net
> http://tech.groups.yahoo.com/group/roZetta/
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