Re: Water heater eating X-10 signal

[ddl@danlan.*com (Dan Lanciani)]

In article <1178039845.524301.204010@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, graftonfot@xxxxxxxxx (Mr. Land) writes:

| I dug out an extra WS467 from my X-10 parts box.  I used a small table
| lamp for testing its operation, right at the panel.  Using clip leads,
| I wired: from ground to one prong of the lamp, from the other prong of
| lamp to the black lead of the WS467, from the blue lead of the WS467
| to what I will call a "test probe".  I also wired the ESM1 from a
| ground to the blue lead of the WS467, in an effort to "see" what it
| was seeing.
|
| I set the WS467 to the same housecode as my pole lamp, which is C4.
| Then I fired up my HomeSeer script to continually send C4 ON, sleep 5
| seconds, send C4 OFF, sleep 5 seconds, send C4 ON, etc.
|
| I first connected the test probe to the load side of the breaker
| feeding the lighting circuit in question.  Immediately I saw new
| behavior on the ESM1 display: seemingly on each command, the LED bars
| indicated four (!) distinct signal amplitude peaks.  That is, 5 bars
| would light, then drop to 3 or 4, then back up to five, repeating for
| a total of 4 peaks, then silence (which I assume is the sleep call in
| the script).

Are you sure the sequence wasn't low then high?  That would be normal
behavior with a repeater, assuming the ESM1 is registering both the
original and repeated versions.  So you see C4, C4 repeated, ON, and
then ON repeated (where repeated is in addition to the second copy
from the transmitter).  A Leviton test set would show only two because
it measures only the "ON" after it is selected by its (fixed) address.

| This happened consistently at the breaker connection.  I
| didn't think to measure at the time but I would say from memory that
| the total duration for the 4 pulses was around 2 seconds.  It really
| looked like something was echoing the control signal 3 times, except
| that the green X-10 indicator never came on, and the WS467 never
| responded.

I would try the 0.1uF capacitor across the WS467.  It is possible that
you have a noise source not related to the water heater but the addition
of the heater circuit changes things enough to make it significant.  Keep
in mind that the WS467 does not have any AGC so it is the absolute level
of the noise that matters (even if it is tiny compared to the good signal).
Another possible experiment would be to use a lamp or appliance module
rather than the WS467; the former are not as sensitive.

				Dan Lanciani
				ddl@danlan.*com