X10 Signal Suckers

There are two types of interference that the X10 signal suffers from; noise that masks the 120KHz X10 signal so that the modules can not "hear" the X10 signal, and unintended trap filters a.k.a "signal suckers" that attenuate or reduce the signal in a power line branch below the usable level.

Table of Contents Trouble Shooting Noise Signal Suckers Solutions Filters Traps Known Problem Devices

Trouble Shooting

Generally it helps a lot if you know how the branch circuits are connected since many times the interfering device is on the same branch. Typical house wiring is inductive and generally attenuates high frequency noise so that problems tend to be isolated to the same branch. This is not always true and there can be some major noise producers that flood the entire phase with noise, but that is less common. The effect of signal suckers (high frequency shunts) are almost always isolated to the same branch circuit.

Phase couplers are important. If you don't have one then troubleshooting is a real bear because there will, at times, be more than one simultaneous problem. e.g. you are on the weak phase and have a signal sucker. The easy solution is to start by installing a phase coupler.

• • Method 1:**

The simplest method is to unplug suspected items and try the troublesome device again. There is a small list at the bottom. This works amazingly well for most homes with modern electronics. For instance I simply turned off my A/V equipment in the living room at the surge suppressor to debug a lamp module on the same circuit.

• • Method 2:**

The next method is to turn off all the breakers in the home. Then only turn on the circuits being tested. First turn on the circuit that contains the X-10 transmitter (i.e. CM11 or CM15). Use a lamp module to test that circuit. Clearly you might also need to turn on the breaker controlling Misterhouse if it is not on the same circuit with the X-10 transmitter. If that circuit works then try tuning on one circuit at a time. **Important:** use a second lamp module to test each new circuit. Try controlling both lamp modules to make sure that the one on the X-10 transmitter circuit continues to work. If that one quits working you might 1) have a really large noise generator or 2) somehow broke Misterhouse or the X-10 transmitter. Always testing both lamp modules ensures that Misterhouse is still properly transmitting the X-10 signals.

Noise

Noise requires the traditional noise filter. See solutions below for some options. These devices will block any 120KHz noise and better ones also block harmonics of 120KHz. This prevents the device from injecting the noise into the power line. Because of their design, these devices also isolate signal suckers.

Signal Suckers

Most modern electronics have input capacitors that form signal suckers. This is done to comply with FCC regulations on emitted noise. Unfortunately it also attenuates the intentional 120KHz signal from the X-10 transmitter. Higher current power supplies tend to tend to have better filters and attenuate the 120KHz signal even greater. In my home this is the primary source of interference with X-10. Because of the inductance in most wiring, signal traps will generally only cause interference on the same branch circuit. This makes isolating them a simple matter of unplugging things until the problem goes away. The noise filters below also isolate signal suckers, preventing them from shorting out the 120KHz signal.

• • Signal level meters:**

Most Misterhouse users seem to solve their problems without resort to X10 signal level meters - however if there were one to borrow nearby at the time of a problem most would grab one of these. Bottom line - probably not something you need to invest in at the first sign of trouble.

An Economically-Priced Signal Meter

Solutions

Filters

FILTERLINC 10-AMP PLUG-IN NOISE FILTER X10 PRO Plug-in Noise Filter

Traps

The filters above isolate traps because they place an inductor between the power line an the input filter capacitor on the problem device. It is possible to simply place an inductor alone in the circuit to isolate a signal sucker. This inductor can be installed inside of a commercial power strip. I chose this method for my A/V equipment in each room. Make sure the inductor is properly rated for the fuse or breaker rating on the surge suppressor. I changed out the fuses to a lower value for safety. Most A/V equipment doesn't need anywhere near 15A. You can see a full write up of this concept here: stovenour.net: X-10 Trap

Known Problem Devices

(Although some of these situations were likely in marginal X10 signal path designs they never the less my give others a hint of where to look)

• All Notebooks - Dell,HP,Toshiba. (The problem is the in lead power supply)
• NEC Television (5 Years Old)
• VHS Player (4 Years Old)
• Samsung CLP500 Color Laser Printer
• Early VGA monitor (Max 800*600 Res)
• Certain brands of CFL lights may induce RF onto the lines and swamp the X10 signal
• Nintendo Wii
• Nintendo Wii Remote Charger