Re: mystery signal

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:
>
> >Troubleshooting X-10 clearly is for the nimble.   You've got a
troublesome
> >situation.
>
> I'm confident I could run this down quickly if my mobility were not so
> severely restricted.

Well, you need to train a monkey or build one of the Star Trek "Exo-comp"
mobile troubleshooting computers to assist you.  I'm just kidding, of
course.  I sympathize greatly because when I was laid up after surgery my
X-10 went wild and I nearly did, too, trying to troubleshoot what turned out
to be a simple problem (stuck Maxi button).

> >I wasn't sure how they functioned.  Why would a triac-based device output
so
> >randomly?  If they're chopping the wave at regular intervals, shouldn't
> >their output be regular as well?
>
> Powerline intercoms predate X-10. I used them in the early '60s.
>
> I'm not sure this signal is from a triac-based device. It appears to be in
> sync with the triac like switching transients that have been on the line
for
> several years (but which are not coming from any of my devices). The
> switching transients come ~1.6ms after each ZC. The endpoints of the
periods
> when this signal is absent coincide with the switching transients but the
> transients are always there even when there is no change in this signal
> presence/absence.

If the transients have been there for years it might be that the device
causing them failed and was replaced by a newer and even noisier device.
Were the pre-existing transients visible on both phases?  (I assume they
were since you've mentioned that they appear to be external to your
apartment, but any differences between the phases might provide a clue to
their origin.)

> >IIRC, you were reporting pretty strong signal voltage of the
interference.
> >What kind of levels of X-10 signal do you normally see in your apartment?
> >If it's in the 3-4 volt range it seems like another indicator that it's
> >something in the next apartment because that seems to be about the right
> >level of attenuation.
>
> That's not a reliable indicator since some X-10 transmitters output 10Vpp
> and others 5Vpp.

Agreed.  I am just grasping at straws to try to figure out where the
probably source is.

> >My only suggestion at this point is to pretend to be the owner and hire a
> >sparky to filter your apartment at the main breaker.  It won't be cheap,
> >though, because of the unusual configuration you have with two feeds from
> >different phases.
>
> It's not worth that. I only have one X-10 device that's affected and it's
in
> a walk-in pantry and is not critical. There are outlets for each apartment
> in the basement for washers/dryers. I suspect the tenant in the basement
> apartment may have plugged something into one of those.

A good guess - but it would be nice to know what it is.  I had a CF bulb
that put out noise that could be seen on the ESM1 but I returned the whole
lot of bulbs.  They only output less than a volt right at the bulb, so it's
hard to see how they could be a culprit.  Still, I would lean towards
something like that, which is why I suggested checking to see if the signal
might not be present during daylight hours.  Of course, apartment buildings
often have hallway lights burning all day and night.

One other possibility might be one of the newer, low energy "Exit" signs.
Some have CF bulbs and some use LED arrays.

I'd lend you my Monterey if I thought it would be any help.  It's a heck of
lot easier to check each outlet in the house than a scope setup.  It would
be interesting to see what it reported at the problem outlet and throughout
the apartment.

Well, good luck.  If I lived close by, I'd love to give you a hand tracking
this down.  Alas . . .

--
Bobby G.