If you have been reading these tutorials, you should know the X10 protocol was developed back in the 70’s by Pico Electronics.  In the decades since then our houses have become filled with various electronic devices, some of which are downright hostile to X10 powerline communications.  Many people blame X10 when their system does not work perfectly.  However, maybe the blame should be redirected at the manufacturers who developed these new devices without any regard for other equipment that might share the same powerline.  The XTB is my attempt to give X10 systems a means to fight back.

X10 powerline control signals are sent as a series of 120KHz bursts coupled onto the powerline.  Many X10 transmitters utilize inexpensive transformerless power supplies.  While small and cheap, transformerless supplies cannot deliver much energy.  Most X10 transmitters output about 5Vpp to the powerline, but that level falls off rapidly as the distance from the transmitter increases.  Because most X10 transmitters cannot supply much current, any "signal suckers" on the powerline will compound the attenuation effect.

The normal approach to combating the effects from problem devices is to isolate them with filters.  Unfortunately, many loads are dynamic, and the powerline environment is always changing.  It becomes impractical and expensive to isolate all potential problem loads with filters.  The XTB and XTB-II provide an alternate means to deal with the multiplicity of problem loads.

Both the XTB and XTB-IIR have transformer power supplies that allow them to send the X10 120KHz bursts onto the powerline with well over 10 times the energy of a typical X10 transmitter.  Their output of 20Vpp or more allow X10 signals to reach much further before the signal strength drops to marginal levels.  The XTB was designed to boost the output of a plug-in X10 transmitter.  Since it drives just a single phase, a good passive signal coupler should be installed when X10 devices are on both phases.  The XTB-IIR includes two output coupling networks, and it will drive a strong signal onto both phases when installed near the main electrical distribution panel.  More information on both units can be found at the XTB Home Page.  Also, please read the feedback from XTB users at the XTB User Reports page.

As you can see from the user reports, the XTB and XTB-IIR provide a single solution to most X10 signal strength issues.  The plug-in XTB is certainly the easiest to use, but it should be paired with a good passive signal coupler for most installations.  The XTB-IIR is a much more capable unit that also includes TW523 emulation and an enhanced repeater.  Although best results are obtained when it is connected to a 240V circuit near the main distribution panel, some have just plugged it into an ordinary 120V circuit, and installed a good passive coupler at the panel.  Because many computers are known to cause X10 problems, I still recommend isolating them with filters even when a XTB or XTB-IIR is used.  And while the XTB or XTB-IIR will solve the majority of X10 signal strength issues, it may not solve problems caused by strong noise generators by itself.  However, the strong XTB-IIR signal paired with custom "signal suckers" to attenuate broadband noise may help in those installations where the noise is hard or impossible to filter.

Some may think that the XTB and XTB-IIR are expensive.  Most consumer electronic devices today are made in China with cheap labor and components bought in huge quantities.  The XTB and XTB-IIR are kitted from components bought from major US distributors, such as Mouser or Digikey.  The kit prices are based on the unit quantity component prices.  Any discount from ordering in larger quantities covers shipping charges, packaging materials, time spent ordering, sorting, and packaging the components, and various fees.  A significant savings is possible for those of you who are skilled enough to assemble one yourself.  Bare printed circuit boards are also available for those of you who have well-stocked parts bins.

Even with all the electronic equipment now in our homes, it is still possible to achieve virtually 100 percent reliability from a X10 automation system.  Many have found the XTB or XTB-IIR to be a major factor in achieving that goal.