There are devices know as "transorbs", that are designed for suppressing transients. They look like disc capacitors, and are used in places like your power strips that you plug your computers into. I am not sure if they would have any application here, but they may, providing you could find one with a low enough voltage rating.
Regarding brush sparking, I believe it is a matter of current and resistance. A clean comutator will arc less, just as your trains wheels will arc less when the wheels and tracks are clean. Did anyone here ever hear of a "spark gap transmitter"? They date back to the earliest days of radio, or wireless as it was called then... A voltage spark, a tuned circuit of sorts, and an antenna. Lets see, we have a good spark acrossed the train wheels and the motor's comutator, and we have a track, that kind of acts like an antenna. I must say I am very suprised that anyone is having trouble with trains interferring with TVs hooked up to cable TV. As a long time HAM, (amateur radio operator) I can tell you that a cable is supposed to be like a pipe. Nothing gets in or out of the air from it. If you are geting train interference, than either the cable has a leak (can happen) or your TV is of poor design and does not have the proper RF shielding or proper filtering of incoming power voltage. Believe me, keeping ham signals out of TVs is much harder than keeping toy train sparks out! It is almost always the fault of the TV receiver, or the installation of the TV set is incorrect, that is the problem. Incidently diodes in series with lamps (or anything else) do rectify AC into pulsating DC, but they also cut the voltage in half, in the case of a simple single diode in series. This is know as a "half wave rectifier". -- Web Site - http://myflyertrains.org email - [EMAIL PROTECTED] 25+ Years of high resolution scans of Gilbert catalogs online! Kris Model Trains & The All Aboard Sets Club! S-Trains list sponsor: http://www.americanflyertrains.com All the Flyer you desire...books and accessories too! To UNSUBSCRIBE from this list send a note to [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
