Re: Cause of some major X10 problems found

["Jeff Volp" <JeffVolp@xxxxxxx>]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in message
news:EvmdnYQ36Ol7jHrbnZ2dnUVZ_u6rnZ2d@xxxxxxxxxx
> "Jeff Volp" <JeffVolp@xxxxxxx> wrote in message
>>
>>  You may remember an earlier post regarding beating compact
>> fluorescent lights producing peaks and valleys similar to a X10
>> transmission.  I found that about 2 minutes after I switch on my
>> CFL "noise generator" the beat frequency between a couple of
>> the bulbs gets low enough that the peaks and valleys occur on
>> alternate half cycles.  If the receiving module just happens to
>> catch enough noise 3 times in a row to recognize a start pattern,
>> the remainder of the message with alternating 1-0's does get
>> through as a valid command.  Even with the enhanced error
>> detection requiring complimentary 1-0's, I did capture one
>> squeaking through.
>
> That's fascinating.  Do you remember the strength of the signal the CFL's
> generated?  Was it low enough so that something like a Stargate located at
> a
> distance might not even record it but a nearby light switch would?

I measure the CFL noise after the X10 bandpass filter because that removes
all the 60Hz.  At that point it averages about 1Vpp, but the peaks can get
as high as 1.5Vpp when they all sum constructively.

(stuff snipped)
>
> Maybe Bruce will donate his noisy PS to you in the name of science so that
> you can examine it on your logic analyzer.  Do you give XTB factory tours?
> (-:  I'd love to see the analyzer in action.  It sounds far superior to
> both
> the O'scope and the Monterey for getting detailed information about the
> X-10
> signal.

Actually, it is a real OLD Tektronix logic analyzer.  It dates back to the
6800 era.  I bought it from the lab when I retired.  They were probably glad
to get it off the inventory list because I was probably the only one who
still used it.

> The more I read at the ACT site, the more respect I have for all the cases
> the XTB-IIR has to recognize and deal with (and fast enough to be
> useful!).
> Especially as I piddle along with my lowly 6 input/two clock BSD.  When
> you
> around to designing the XTB-IIIR please add an auto-configure mode like my
> LCD TV.  It figures out what I plugged into it and sets its mode
> accordingly.  (-:  At least I understand why repeating preset dims (PK
> calls
> them Direct Dims, more intuitively) is next to impossible and why X-10
> abandoned them.

I think the XTB-IIR is probably the end of the line.  Yes, repeating
extended commands is asking for trouble, so the XTB-IIR does not do that.
However, it will certainly transmit and receive them.

Jeff