Suddenly might be an overstement as I’ve been in build mode the last few weeks and always have music playing as I work, but I’ve just noticed all my locos are buzzing quite loudly once they get past about 30 on my Digitrax throttle. I’m using a Digitrax DCS 240 command station/booster. I’ve got 15 locos, and all of them buzz: my first purchase (MTH Alco PA A-B set), my cheapest purchase (Bachmann sound value RS1), my most recent (BLI Challenger)–and everything in between, they all buzz loud enough to be heard over the speaker sounds (I set all max volumes at about 40%, so they are relatively quiet). Heres some more detail:
I’ve got the DCS 240, a PM42 splitting the layout into 4 districts, 2 PSX-ARs controlling 2 reversing loops, and a Digitrax AR1 controlling a reversing section
Track – along with those boards – is isloated on its own power. Tortoises, DS64’s, turntable motor, etc are all separate power.
Ran things with the toitoise etc. stuff unpowered. No change.
Tried changing out the power supply to the DCS 240/ aux boards. No change.
Tried plugging the DCS240 into a different circuit in the house. No change.
Swapped out the DCS240 for a DB150, figuring something might be wrong with the DCS240. No change.
Changed OpSw 20 to “closed” to kill analog signal on both command stations. No change.
Changed a few loco’s CVs to use Digital Only (though I do this with every new loco, so they were probably set that way already). No change.
So I thought maybe one of the PSX-ARs or PM42 was causing an issue.
And here’s where it gets really weird: I set up a test track in an entirely different room, opposite side of the house, different circuit than the train room. I connected just the DB150 to 12’ of track. Tested 3 locos. Still noisy.
So I thought, maybe my 402 throttle is whacked. Plugged in a UT4, no change.
It’s not too likely that humidty or lack thereof would cause this. What exactly is buzzing, is it the motors, or the gears? If it’s the gears, maybe all the grease did dry up.
That it’s all locos, and happens on two different command stations, it’s not the signal coming out of either of those.
That leaves the decoders - but something to affect all 15 is about as likely as me winning Powerball. A continuous buzz like a DC loco on DCC would be like there was some connection directly between track and the motor, however this would fry the decoders. And even a mistaken program on the main to address 00 that would do something like disable silent running shouldn;t do this because the CV isn;t the same on all decoders.
Have you tried doing a reset on the system? OpSw 39 (might be OpSw 40 on the DCS240)? It could be that somehow you managed to enable one of the alternate protocols that Digitrax can generate, like Marklin.
The buzzing sounds like the motor— hard to pinpoint but it just sounds more electrical than mechanical (closest analogy would be an electric razor)—but it gets louder as speed increases so in that respect seems almost gear related. I’ll try the command station reset tomorrow morning. Also will factory reset a few decoders. I will also open up the worst offender—my BLI PAragon 2 NW2 switcher, and grease/lube the gears. It’s an odd egg to crack for sure.
On an aside Randy, you are a JMRI guy, right? I tried to reset CV8 to 8 on that BLI switcher, but Decoder pro wont allow me to change that CV. So I used the single CV thing in the Action menu, that seemed to accept the change, but now that loco is unresponsive to 03 as well as it’s previous 4 digit address. Odd.
Giving it a rest for tonight, and now I‘m just getting more irritated that the Patriots will probably go to the conference playoff (and more) again. All respect to the Patriots, but some variety in the Super Bowl would be nice.
The correct way to do a reset with JMRI is to open the roster entry and then in the top menu select Reset (it’s to the right of ‘menu’). That will bring up a dropdown menu, click on Factory Reset and a box will open giving one or more choices depending on the decoder.
Good tip in the JMRI decoder reset. I was not aware of that.
Meanwhile, I may have found the culprit. And if I’m right, it’s probably very, very bad. I asked myself “what changed since I noticed the buzzing?”—I had added a bunch of scenery around my engine terminal. And I used some Arizona Rock and Mineral GN Empire Builder Basalt ballast.
This morning I ran a magnet around my track to see if any gunk might be causing some weird interference, when I got to the terminal, all of a sudden I get these little black specks all over the magnet. So I go back to the scenery shelf, stick the magnet in my tub of GN Empire Builder Basalt ballast, and its instantly covered with the stuff. It’s magnetic! Not just a few magnetic particles, ALL of it is magnetic. Whaaaaaat??!! It’s labelled as mainline ballast so no idea why it would be magnetic. Very odd as Arizona R&M seems to have a very good reputation. Their website is down right now so I cant check to see if I missed some sort of disclaimer about magnetic particles.
I hope I’m wrong but its possible all my loco’s magnetic parts have sucked up bits of that stuff while moving in and out of the terminal, and I’m not hearing a buzz, I’m hearing a grind—from the worst possible places. That would explain why they all started getting noisy at the same time, and why they were noisy with a different booster on a test track in another room.
Well that can certainly cause weird things if it’s stuck all over the motors. It will also stick to speaker magnets and likely cause distortion on the sound units, as well.
Not to mention increased resistance between the rails!
Can you isolate the engine terminal and check the resistance between rail A and B?
I found out some years ago, much the same way you did, that a bunch of the Highball brand cinders I have had lots of ferrous gunk in it. Fortunately I discovered this before I used any on track. I now have it labeled “Not For Ballast Use!”
I also followed a suggestion by RR Mel and made a magnet pick-up car using a neodymium magnet glued to the underside.
Is Basalt magnetic?
Because of the presence of such oxide minerals, basalt can acquire strong magnetic signatures as it cools
Unless one has open frame motors the ballast shouldn’t be a problem, metal particles shouldn’t ding an enclosed motor. But I do agree with Randy it will screw up speakers.
I run a flat car with a magnet hanging just above the rails in my freight lineup to pickup metal parts that have fallen onto the track, periodically it picks up metal partials that would cling to the speakers in my tenders.
I’m going to build a magnet car this week. Engine terminal is on it’s own power (one leg of a PM42), I’ll try to do some resistance measurements tomorrow night. Meanwhile, that magnetic stuff is spread all over the place around the turntable and ray tracks—- so the entire yard has become a magnet. So I need to scrape it all out of there. Ugh. From now on I will stick a magnet in any scenery material before it goes on the layout. Just to be safe.
You guys have given me a lot of things to investigate and/or fix here, so might be a few days before I post a progress report. Hopefully Mel is right and there’s nothing in the motors. I appreciate all the input!
This magnet will pull the Titanic of the bottom of the ocean. It cost $4.00 at the auto parts store. Every once in a while I move it along the track with my fingers between the track and the rail, my fingernails sliding on the rail. I can’t believe the crap it picks up and I wonder how a lot of it even gets there.
Wow, this forum never disappoints. I never thought of the issue but I will have a magnet car by week’s end! And, I’ll check my ballast before installing. I knew there was a reason for procrastinating.
Not sure I’m doing this right (I’m a novice at best with electrical things), but with track power off and all Locos and lit passenger cars removed from the layout, I measure about 20K ohms, some areas as low as 18.5, others as high as 22. Engine terminal tracks read within this range. BTW, it takes about 20 seconds for a reading to stabilize. I’ve got an Innova 3320 meter, if that matters.
Heres what happens when I stick a magnet into my tub of ballast. Yikes! Incidentally, when you wet and glue this stuff down, it dries much darker than it was in the bag, almost black.
A resistence measurement wiuth the DCC syste, connected is just reading the output stage of the booster. It takes a long time for the reading to stabilize because there is a capacitor or two in there. You need to disconnect anything attached to the track to get a valid readong - it should end up being infinite ohms, open circuit. If it’s anything significant, say below a few megaohms, then it starts to be a concern - although too low and it’s just a dead short on the DCC system, a high enouhg value and it’s just putting some additional load on the system. Neither condition will make all the locos buzz though.
That would seem to be something you wouldn’t want to apply to the layout, based on how much sticks to the magnet. And they laugh at Woodland Scencis supposedly being made out of walnut shells - well, I’ve never seen a walnut shell that was magnetic!
So to get an accurate resistance reading, I should pull the terminal plug from the front of the DCS240 so there is no chance of any power whatsoever getting to the track, right?
I have received from Arizona Rock and Mineral ballast that responded to a magnet. However, I have not had any problem with the layout in 3 years. I have infinite ohms when measured with my meter from one rail to another.
As a side note. Some weather chauks also can be picked up with a magnet. I have some colors of Pan Pastel that responed positively to a magnet. Did you weather your track with chaulk?
I’ve disconnected every power source of from the rails … booster terminal plug, PM42s, PSX-ARs, loconet, at this point there shouldn’t be anything with a capacitor connected to the rails. I get an initial reading of infinite on my meter, then it starts to jump around a bit. It does this on all 4 power districts.
So I killed the circuit breaker in the room just to double check. Same readings. If the layout was one district, I would assume this means there’s some sort of debris on the track—just enough to be weird but not trigger a short (I do the quarter test on all my track foot by foot, everything trips without error). But this happening on 4 districts seems to rule that out.
I will be doing some more digging tomorrow night, will keep you posted.
