While yoou did say you swpped the DCS240 for a DB150 and the problem remained - there are maybe 2 things to try. First, with the layout disconnected from the track terminals on the DCS240, check the voltage (with the system on and track power turned on of course) between Rail A and the Ground terminal, and Rail B and the ground terminal. They should be practically identical. If not, dial up address 00 on a throttle and make sure it's on speed step 0 and check again. So long as address 00 is at 0 speed, the voltages should be identical, you're measuring each half of the DCC waveform. This method of checking voltage is in a tech note in the Digitrax tech support depot. If there is a large difference - it generally indicates a problem with the output drivers in the command station.
Second thing - you switched out with the DB150 - but did you use the same power supply to run both the DCS240 and the DB150? The easiest way to check this without a raft of electronic gear (because of trains run fun other than the buzzing, the voltage is probably just fine) is to find some alternate power supply - if you have an AC one of some sort it can power the DB150, even if it's not 5 amps. You need enough to run the DB150 and ONE loco - idea here being to see if there isn't something coming from the power supply that is causing the buzzing.
I've always used the Norelco style electric razors - if one of my locos was as loud as those things, it wouldn't be anywhere near acceptable
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Rail A/Ground and Rail B/Ground read a rock steady 7.4V. I've tried different power supplies on both the DSC240 and the DB150, no change. Tried different throttles, and just Decoder Pro with physical throttles unplugged, no change. When I compare noise to an electric razor, by quiet I mean a razor the vintage barber shop uses----the guy with the original 1952 chairs and 30-pound razor. You can barely hear the thing unless its in your ear. Noisy is the cheapest thing on the market trying to go through a tough beard.
I'm starting to believe it has to be motor or decoder specific, since the amount of noise varies. My Walthers P2K F3's run very quiet---wheels on rail noise is much louder than any motor noise. A set of Intermountain FTs runs fairly quiet forward, but very noisy backwards. Those MTH PA's and the little BLI switcher are loud no matter what. I'm not gonna mess with the steamers until I figure out the diesels.
So here's my next plan of action: I think we've ruled out track/electronics/errant dcc signals or active interference as much as we can for now, and I need to focus on motors/decoders.
As always, I appreciate all the help!
One thing I just realized: that Walthers P2K F3 set that runs quiet was not sitting in the engine terminal for 2 weeks. It was on the other side of the room on a passenger siding.
I don't know your situation of when you first noticed the buzz. You mentioned music playing while your worked and magnetic ballast being applied to your layout. It would be helpful if you nailed down the timeline to be sure that nothing buzzed before the ballast was laid, but maybe with music playing you never noticed.
What I can say is that a lot of decoders buzz. Its doesn't seem to be widely spoken about. You may find that silent decoders aren't all that silent, and that the volume levels of onboard sound locos mask a buzzing noise that can be heard on lower volumes. I simply have a test track with an NCE power cab hooked up via two terminal wires, so its about as simple as you get.
I also know that DCC signals can be pretty phinicky. I would think that any magnetic powder or particles that have worked their way onto the decoder or messing with the wheel/track signal pickup might alter things enough to cause a buzz that was once never there.
If it were me, knowing that many decoders simply buzz anyway, I would start by removing all of the magnetic material from the layout, tracks, and locomotives before I spend the money swapping out locos, decoders, or motors.
BTW, QSI and Tsunami sound decoders, as well as NCE DA-SR nonsound silent decoders dont buzz from my experience, so if you're going to buy another loco, try one of those as a control loco. There are probably others that I am not aware of.
- Douglas
Can you take your engines to an LHS, train club, train show or a friend's layout and try them there?
It takes an iron man to play with a toy iron horse.
MisterBeasley: I thought about that, but the LHS has a small DC only layout, and I'm a lone wolf--its something I do just for my own relaxation and on my own schedule or lack thereof.
Doughless: The noise definitely became an issue after the ballast was installed around the engine terminal--that's the only smoking gun in the timeline. I always have music playing, wether working or running, but its never at a volume that would preclude casual conversation. So it may have masked a bit of noise all along, but would not have masked an extremely noisy loco, like the Alco PAs or the NW2 switcher. My Porter Cable cordless drills at very low RPM make about the same amount of noise.
With the 2 locos I took apart and cleaned, there was no evidence of those magnetic particles. This morning I took the Dyson vacuum with a fine cloth over the hose and vacuumed the whole area. The cloth had 7 particles and some ground foam stuck in it. A magnematic coupler wont pick up any particles even when dipped right into the tub, wheres the magnet pictured in my earler post comes out covered with the stuff. That strong neodyum magnet had to get within 5/16" of the stuff before it starting sucking up particles, so I dont think there's anything getting sucked up into the locos. But the idea that it created some weird interference field that slowly messed up some decoders or motors as they sat there for 2 weeks sounds like science fiction.
I think I need to just give this thing a rest for a week or so and mess around with other stuff. Maybe its the moon phase . Or my beer fridge (actually, I already tried unplugging the fridge. And the stereo. And the wifi).
Do you have a DC supply you can use to test? If you haven't disabled DC operation in the decoder by setting CV29, they will run on DC - and if they still buzz it's more likely a mechanical problem because when the decoder runs on DC it basically just turns on the motor drive transistors to let the power through fromt he rails, with little more than the voltage drop common to any semiconductor juntion. The circuitry, at least the part that drives the motor, is not active when running on DC. So, buzz on DC, it's a motor/mechanical issue, no buzz, it still could be the decoder or something in the power system.
Have you tried connecting some extra track right to the output of the DCS240 or the DB150, no breakers, no reverse controllers, just the DCC right to the rails. That will eliminate it being any of the wiring or the track on the layout.
Randy, I'll try the DC test sometime this week. I've got the command station and all my decoders set for digital only, but easy enough to reset a few for testing. This morning after I ran your votage test on just the track output, I figured what the heck, I've got those wires disconected from all the other electronics so I conected them straight to a power districts rails with some alligator clips. No change.
Another stab in the dark might be a firmware upgrade in the DCS240 and throttle. But I dont have access to a Windows laptop so I'm out of luck. In fact I dont even know anybody who has a Windows laptop---I'm a graphic designer, our entire company is Mac, as is my wife's. Most of my friends who need anything more than a tablet are in music or video production, so they are all on Macs. Heck, my brother is 2nd in command at a local university IT dept and even he doesnt have a personal Windows laptop. And I dont think JMRI's Digitrax firmware update tool supports the DCS240 yet.
A Boot Camp inplementation of relevant Windows OS should be practical on almost any Intel Mac. I suspect there are also a variety of VMs that can run some flavor of Windows from within OS X.
It's going the other way that poses the Hackintosh fun...
OS emulators aren’t a problem, it’s shelling out 130 bucks for a copy of Windows. A bit of financial overkill to upgrade 2 pieces of firmware. Eventually I’ll track someone down who has a Windows laptop.
180 day trial is your friend.
Sorry to keep this thread going, its getting a bit long in the tooth, but here's the latest progress:
Randy: my old DC transformer was one of those little Tyco gold box things, lots of corrosion, so I didnt dare try it and have not been able to do the straight DC test. But I am convinced at this point that it is motor noise.
Which brings us back to that magentic ballast. I dont know if its the root cause of the weirdness, but I think regardless I need to get rid of that stuff. I did a little experiment: put some of it on some wax paper, waited a few days, and here's how it reacts to a magnet after being glued/drying twice:IMG_1530_1200px
Ouch. Oh well, I had 2 ray tracks that werent quite square with the turntable bridge and caused some issues anyway. Its an excuse to fix em.