XTB Logo designed by Jack Edin.

The X10 Transmit Booster (XTB)

The X10 automation protocol was developed by Pico Electronics back in the 70’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XTB – (The original basic XTB has superceded by the XTBR.)

XTBR – Redesigned version of the original 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-232 – X10 powerline interface for PC-based automation systems. This plug-in unit emulates the CM11A “real-time” protocol, and can be directly used as a CM11A substitute for PC-based automation systems such as HomeSeer and Home Control Assistant. It does not have schedule clock, and will not support any controller functions itself, but it will act as a powerline interface for ActiveHome or ActiveHome Pro running on the PC. It handles all CM11A direct-action commands, but will not accept any downloaded functions such as timed events or macros. While not quite as powerful as the XTBR or XTB-IIR, it outputs a much stronger signal than the CM11A.

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.

The X10 RS232 Computer Interface (XTB-232)

Many of my customers have asked for a XTB that can directly interface with PC-based automation software. The XTB-232 is a plug-in module that combines a single-channel X10 powerline link similar to that in the XTBR with an opto-isolated RS232 serial link that can be connected directly to a computer. It emulates the CM11A “real-time” protocol, and can be used as a CM11A substitute for PC-based automation systems such as HomeSeer and Home Control Assistant. It does not have a schedule clock, and will not support downloaded controller functions, but it will act as a powerline interface for ActiveHome or ActiveHome Pro running on the PC.

The X10 Active Noise Reducer (XTB-ANR)

Many of us have dealt with the noise produced by CFLs and other electronic devices by isolating them with X10 filters. The XTB-ANR is an alternate solution. It is a small plug-in module that will significantly reduce even in-band noise on its circuit. It continually monitors the powerline for PLC signals, and will switch off its attenuator when a X10 or Insteon signal is detected. One plugged into each phase near the distribution panel will significantly reduce the overall noise levels throughout the home, including any coming in over the utility feed. If there is a known strong noise source inside the home, best results may be obtained by plugging a XTB-ANR into the same circuit. The goal is to restore the relatively benign electrical environment that existed when the X10 protocol was first developed.

The 10 Amp Plug-In X10 Filter (XTB-F10)

Most of us have used the X10 XPPF plug-in filter to isolate signal suckers or noise generators. That is a very good low-pass filter, but it becomes warm and can start to stink when pushed near its 5 amp rating. The higher current filters available from SmartHome and ACT are notch filters. They are effective at the 120KHz X10 bandpass, but can allow noise outside that bandpass to leak through. As a result, a particularly strong noise source outside the X10 bandpass can still cause problems.

The XTB-F10 is an alternate high-current filter. While it has similar topology to the SmartHome and ACT filters, its values have been selected so it behaves much more like the XPPF low-pass filter. The XTB-F10 will be effective isolating even very strong noise sources outside the X10 bandpass.

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