Signal Interference Found! No Need for Cherry Bomb Cannon

Good detective work there. That's something I would probably not have found or even suspected? Glad to hear you got the problem solved and are once again back to running trains with no problems.

Wall warts are a frequent cause of fires.  I was in a RR museum (just be and curator), and smelled something hot.  After must searching, we found a red hot wall wart.

JDaddy, how about telephones, etc?  Nowadays wall warts, like leprachauns, are everywhere.

Susan Deats posted:

My DCS signal has been gradually degrading over the past year.   The signal interference was caused by an over heated power adapter in my office on the level above my Run Room (about 13' from TIUs through the floor).  Yes, I know.  That's supposed to be too far away for interference.

This is the first time I've looked forward to playing trains in a long time.  I had tried everything to restore a reliable signal and it just kept getting worse.  I finally stopped, started a log, and determined to find the interference or make a cherry bomb cannon to blow up the whole Run Room.

Disclaimer:  My methods with electronics are based on hunches with no formal technical knowledge.

I started experimenting in my office where I was making the log list.  With an AM radio tuned to a weak station, I put the radio's tuner next to each electronic item and wall wart one at a time and listened for static.  Almost all put out static but a really warm power adapter put out loud static with a whine.  I disconnected that adapter and let it cool off.  My DCS signal is better than it's ever been on all track!!  I didn't even have to start unplugging everything in the Run Room.

Of course now I have all good connections, clean track, one new TIU and remote, and well maintained engines because of all the Troubleshooting I was doing in the Run Room.

 

Wow...this is a serious find and very helpful post..and just got logged into my favorites file. I am all DCS 4.20 with several 4 and 5 engine MU's  ps3 and 2 which run very reliably ....other members of this forum not so fortunate. EM interference creates havoc in many fields. My first experience was a cb radio in a porsche i had 30 years ago...key up the mike and the cruise control accelerated. Thanks for sharing!

These Mu's in this video just keep on chugging...the Guilfords/Pan Am approaching 5.5k scale miles..

Oh boy. Another thing to make me search. I have the wireless at Artpark, the wireless in the boats nearby, the boarder patrol equipment, neighbors equipment, a dozen or more wallwarts. Have I forgot anything?

Bird do, leaves, twigs, sap, seeds, .......

Technically, interfering items would have to be within 12 to 20 feet (guessed distance) of the TIUs.

I also suspect that extreme interference could get into the system via track and wiring connected to TIUs. 

Please note that most hard to find interference can come from malfunctioning or aging electronics and wall warts.

To isolate a hard to find interference source in your home, shut down all your circuit breakers in your house panel and sub panels Except your layout area.   If that restores your DCS signal you know the interference is Not in your layout area.  Turn house breakers  on one at a time, checking for signal interference each time.  (You may have to wait for interfering items to warm up before failure appears.)

Keep a log file during the search process so you don't have to back track.

Technically, interfering items would have to be within 12 to 20 feet (guessed distance) of the TIUs.

Why do you say that?

Would have to ask Dale M. if a switching power supply going bad would radiate a signal through the air or through the house wiring? I would lean more towards the house wiring, but strange stuff happens.

I am glad that you found the troubles, Susan. I recall your troubleshooting posts for at least the past year. Run those trains!

There's a lot of evidence that switchers create rf on house wiring. In fact the switching transients are requiring heavier wiring gauges than previously adequate wiring size for a specific load current. The problem is more serious in commercial buildings with all the electronics in them but occurs in residential buildings as well. So don't rule any switching supply or charging device out of consideration.

RJR posted:

Technically, interfering items would have to be within 12 to 20 feet (guessed distance) of the TIUs.

Why do you say that?

As I mentioned, it's just a guess based on conversations with my son who designed the DCS signal filters.  I also don't think that interference is in the house wiring.  The Run Room has its own electrical sub panel.

That power adapter is powering my MagicJack Plus which I use for long distance calls and a second phone line.  I do not use a cell phone.  The interference could have come from the MagicJack phone line generator that is connected through my home router instead of my computer.

It's a great day in the Run Room.  My DCS Wifi has been restarted after interference was cleared and tablet, wifi module, and tius are all updated to latest software and firmware.

Now that all is running as it should I can connect the rest of the TIUs with Wifi.