Re: a stupid X10 sprinkler question

["Jeff Volp" <JeffVolp@xxxxxxx>]

"Andrew" <hawk007@xxxxxxxxx> wrote in message
news:1151338856.037521.121530@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> You are the celebrity who just created the breakthrough XTB signal
> booster, aren't you!

No celebrity.  Just another contributor like some other folks here.  We have
been using X10 with near 100% reliability since the 70's and I wanted to
help some others increase the reliability of their systems too.

> I had browsed some postings about the XTB, and it is, of course,
> reassuring, for those having second thoughts about investing into the
> decades-old X10 technology for the first time.

There is a lot of "old technology" we rely on in our everyday lives.  X10
has worked almost 40 years, and there is no basic reason why it can't
continue to work for years to come.  Sure, there are newer systems with
higher data rates, but we don't know what problems they will run into over
coming decades.  I still think X10 gives you a lot of value for your dollar.

> I have only a vague understanding of electrical circuits, but I did
> wonder about reception across the two (110V?) circuits that a home
> normally has.  Does the X10 signal reception by a device on one line
> worsen significantly when it is broadcast from a device on the other
> line?  I realize this may vary from house to house, but perhaps there
> is something inherent in the double-line circuit that impedes the
> signal across the two subcircuits?

When X10 devices are on both phases, a coupler is generally necessary to
propagate the 120KHz X10 signal from one phase to the other.  Otherwise, the
signal on the opposite phase is usually much lower amplitude than the
"transmitting" phase.  The coupler will distribute the transmitted energy
across both phases.

> When I set up my X10 system, I'll share any interesting findings here,
> but, I'm curious if the XTB is an absolute necessity, in such
> cross-line situations.  (I'd order one sooner if that's the case ;-)

Something like the XTB isn't needed in a relatively small house with a clean
X10 environment.  Even before the XTB, we had acceptable signals here after
taking precautions to eliminate most X10 interference sources.  We had one
cranky light with a compact fluorescent bulb that occasionally would not
turn off.  It has not failed to operate correctly since installing the XTB.

> Also, the "underground multiconductor cable" you mention was new info;
> I'll do some research about it, but if anyone has any other tips
> (caveats? such as when moles/voles are on the premises) regarding this
> underground cable or anything else, they are, of course, very welcome.

I'm assuming your valve manifold will be out in the yard.  The building
supply centers sell multiconductor cable designed for this application in
the sprinkler section.  In my case, I ran it a few inches underground, and
through a small hole drilled through the concrete foundation just below the
ground level.  Then it runs to the Rain 8 located conveniently near an
outlet for the 24V transformer and TW523 interface.

Jeff