XTB
Beta Test Report by Robert Green
robert_green1963@yahoo.com
Every once in a while you come across a product
so useful that it changes the fundamentals of how you live and work. Recently, I had the opportunity to help beta
test fellow newsgrouper Jeff Volp’s XTB (X10 Transmit Buffer) and I can say
without hesitation that this is one of those “breakthrough” products.
Anyone who has an even moderately complex X-10
based system has more than likely been sucked into the netherworld of signal
attenuation. Transmission problems are
the work of a variety of demons, pixies and Orcs that inhabit the average
home’s power lines. The XTB is like a
mighty electrical Excalibur, capable of slaying the motley army of X-10 demons
with a single slash.
What is it?
Well, it’s almost like the mythical carburetor than runs on water. If it were a rifle, you’d never miss. If it were a cell phone, your calls would
never be dropped. If it were a power
drill, you’d be able to punch through stainless steel ingots as if they were
butter.
The XTB is an amplifier unlike any you’ve ever
seen. It takes the real-time output of
an X-10 transmitter like a TM-751 or a CM11A and turbo-charges it to previously
unheard of levels in the X-10 world.
(At least I’ve never heard of them!)
The output is so high that both my Monterey Signal Analyzer and my ESM1
bar graph meter “pegged” out at their maximum levels (4v for the former, 5v for
the latter) at a considerable electrical distance from the XTB.
It was fairly easy to calculate the voltage
based on extrapolation. I compared the
voltage drop between point X and Y with a weak transmitter like the CM11A. Then I repeated the readings with the XTB. Based on the output voltage, I concluded
that the signal exits the XTB at 22 to 24v.
Admittedly, it’s nowhere near as precise as an o’scope but the
attenuation ratios are fairly consistent in my house for point to point
readings. If the CM11A clocked in at 50mV
at a particular receptacle, adding the XTB would boost that reading to .25 volts,
or about 5 times the original signal strength.
Even with 10 X-10 filters deployed throughout
the house, my humble abode is an X-10 nightmare. Lots of X-10 transmitters, lots of PC and hi-tech gear, lots of
UPSs, switching power supplies and other tiny, twisting passages for X-10
signals to get lost in. In short, a
house full of X-10 demons, ready to absorb or corrupt an X-10 signal at any
time. I’ve gotten used to the fact
that my wife’s sewing room was beyond the reach of X-10. She’s actually glad that it is. When I plugged the Maxicontroller into the
XTB the sewing room lights flashed on and off even though they never had
before. The signal, as read by the
Monterey, was a fairly low (but still very reliable) .11 volts. But what was more peculiar is that the
sewing room was on a different phase than the Maxicontroller. So what was coupling the phases?
I decided to check at the panel. All of the circuits on the phase opposite
the transmitter were evidencing a steady .11 volts. I turned off the central AC breakers, expecting to see the
Monterey read 0 volts. No change. Steady .11 volt signal. I turned off the furnace. No change!
I shut down EVERY breaker in the panel except for the meter and the
TM751/XTB combo. That would surely reveal
the “good” elf that was somehow coupling the two phases of my house. But once again, there was no change.
After a flurry of emails to Jeff, it became
clear what was happening. The XTB
signal was SO strong it was coupling at the pole transformer! That might not be
the case with other houses. My power
pole transformer is less that 100’ away from the breaker panel.
I threw the XTB every curve I could think of,
rummaging through my box of X-10 goodies for test candidates. I tested the XTB against several flavors of
transceivers, from the RR501 to the TM751 and even the Robodog. If you’ve got more than one transmitter,
you may need more than one XTB. Unlike
Smarthome’s BoosterLincs, the XTB will only amplify signals from the device(s)
plugged into the unit’s outlet.
While you can’t plug in a vacuum cleaner into
that outlet, you can plug in a power strip and have the XTB amplify several
devices plugged into that strip. I’ve
currently got a CM11A, a TM751, a TW523 and a SmartMaxi-controller plugged into
the outlet strip without any apparent issues.
I even plugged a CM11A into the XTB and then a TM751 into the CM11A ’s
pass-through outlet without a glitch.
I’ve also tried the Leviton All Housecode Transceiver, the X-10 Mini
Timer, Mini-controllers, and the IR543. All worked without incident. The SmartMaxi (All Housecode Maxicontroller
from Smarthome) with its macro capability was particularly enhanced by the XTB.
One of the nicest benefits of the XTB is that it
may allow you to kiss your active repeater goodbye. I disconnected my Leviton repeater a long time ago because it
would lock up far too frequently for reasons I could never quite pin down. I avoided needing a repeater (or even a
coupler) by using TM751’s spread throughout the house at the very end of each
circuit. This kept them from
interfering with each other, mostly, but it really created problems using a
CM11A or TW523 based controller like the Ocelot. There was no way to insure that the output from either unit was
able to reach all of the circuit ends -- until now, that is. The XTB is certainly going to change the
way I’ve got my X-10 units deployed but it will be for the better in the long
run.
The XTB also turns out to be a very useful
adjunct to my X-10 power line meters.
With the XTB plugged into an outlet about 10’ from the panel, I see a
signal everywhere in the house, which is about 1000 sq. ft. That’s been pretty helpful in finding
unusual signal suckers because I can see a signal and calculate the attenuation
whereas before the signal would be too weak to even register on the meters.
I’m sure Jeff will fill in the pricing details
and all the usual warnings. I’m starting off with two assembled units because
of my less-than-sterling solder skills.
I’ll probably even try building one of my own with a little help from a
better solderer since there are surface mount components that have to go on the
board towards the end of the assembly process.
I recommend buying at least one assembled one. If there was a program called “This Old Circuit Board” Jeff would
be one of the hosts. I showed the XTB
to a friend, asking him if he could solder one for me. His comment was “not like that that’s
perfect!” He was floored by the how
neatly Jeff had assembled the beta. So
was I.
If you’re looking for an X-10 dragonslayer get
yours hands on Jeff Volp’s XTB.