XTB Logo designed by Jack Edin.

The X10 Transmit Booster (XTB)

The X10 automation protocol was developed by Pico Electronics back in the 80’s. Many of us were first introduced to home automation through their products. Back in those early days the home electrical environment was relatively benign, and the simple X10 protocol worked very well. All we needed to do achieve reliable operation was to add a simple passive coupler, or perhaps a basic repeater in larger homes.

Since then the home electrical environment is has become much more complex. Many of the devices used today are downright hostile to X10 communication. Many of us have installed filters to isolate those devices from the powerline network. However, one significant issue remains – signal strength. As we add more and more devices to our electrical systems, each of them absorbs some X10 signal. The worst offenders can be isolated with filters, but the sheer number of loads takes a toll on signal strength. The XTB “X10 Transmit Booster” was developed to combat this problem.

The XTB, XTBR, and XTB-IIR are designed to boost X10 signal levels. Unlike the inexpensive transformerless supplies used by most X10 transmitters, these units have 6-watt transformer power supplies that can provide the peak currents required by their powerful transmitters. These units output at least 20 times the power of typical X10 transmitters, and will provide much stronger signal levels throughout a home.

Please read the linked review in Home Toys eMagazine. Also, read the reports from some of the people who are using the XTB or XTB-II/R as a central part of their home automation system. While intended primarily as kits for assembly by skilled individuals, assembled and tested versions of these units are also available.

Which unit should I choose?

XTB – The original 120V plug-in X10 Transmit Booster. This basic unit boosts the signal coming in through its X10 Input receptacle to a much higher level.

XTBR – Redesigned version of the 120V plug-in XTB that includes a repeater capability. It provides direct X10 Boost like the XTB, and will also repeat all valid X10 commands it receives over the powerline, including the “doublet” extended commands produced by the CM15A and some other controllers. Because it doesn't waste energy on the superfluous 3-phase bursts, it produces a slightly stronger output than the XTB.

XTB-IIR – An enhancement of the now discontinued XTB-II two-phase unit that includes a smart repeater. The XTB-IIR has two coupling networks to drive a high power signal onto both phases. The XTB-IIR provides direct X10 boost and a repeater capability like the XTBR. It also provides TW523 emulation to function as a powerline interface for high-end controllers such as Stargate, HomeVision, or the Ocelot. Its more complex circuitry provides higher sensitivity than the XTBR, and the XTB-IIR has an even stronger output than either the XTB or XTBR. A single output 240V 50Hz version of the XTB-IIR is also available for international applications.

XTB-III – A 3-phase version of the XTB-IIR. This unit is primarily intended as a high power 3-phase powerline interface for high-end controllers that normally use the TW523. Since it doesn’t have three independent processing channels, its repeater function can only be used on a 3-phase system if all transmitters are confined to the same phase that is connected to its Phase I input. However, the XTB-III will function perfectly as a repeater on a standard North American 120/240V split phase system. With its even larger power supply, the XTB-III outputs the strongest signal of all units. A 240V 50Hz version of the XTB-III is also available, but it has the same restriction on repeating commands received on only its Phase I input.

The X10 Signal Meter (XTBM)

Those of you who have read my X10 troubleshooting guides have seen my recommendation for using the ESM1 X10 signal meter to aid the process. Unfortunately, the ESM1 has been discontinued along with another unit in that price range. That left only the simple X10 XPTR (and its Leviton clone), and units costing several hundred dollars. Since those are clearly beyond the means of many X10 users, I developed the XTBM X10 signal meter to fill the gap.

The XTBM displays X10 signal voltage, carrier frequency, and last decoded X10 command. It also displays powerline noise, and will indicate various types of errors that plague X10 communication, including the ubiquitous “bad start code”. With its 10mV resolution, the XTBM should be a valuable tool to help you track down troublesome X10 problems.