Verification

For Christmas this year, my wife noticed that I had been eyeballing a Digitrax Empire Builder Xtra DCC starter set. The set was complete with DT402 throttle, DB150 booster, 15VAC power supply, and Loco Net panel, and even included a Bachmann DCC equipped F7A Erie-Lackawanna locomotive.

The reason I had been eyeballing the Digitrax set is that I noticed when I speed matched my locos at home on my NCE PowerCab they played very well together, but when I took them to the shows and ran them on the club layout (which runs on a Digitrax system) they no longer did so.

Another reason is that some - most, to be honest - of my TCS decoder equipped locos hesitate when you roll on the throttle on my home layout, sometimes taking up to a half a second to respond to throttle increases (they slow down just fine). I suspected that having the NCE firmware updated so that I could install the WiFiTrax WFD-31 had this unexpected side effect, because I hadn't noticed a problem until sometime after I had the work done.

Side note, no one else I have ever talked to, either in person or on line, has had this problem. Go figure.

One of our club members has been involved in DCC since the get-go and he said the track voltages were different between the two systems. He had no idea why the TCS decoders had a delay on the NCE at home but not on the Digitrax club layout. At any rate, I wanted a Digitrax system so I could compare locomotive speeds and hesitation tendencies between the two systems. 

I have a Digitrax Zephyr, but it doesn't show locomotive speed so it wasn't much use in comparing locomotive speeds at 50% and 100% throttle settings. The set I was looking at had a speed percentage display, so it would have done quite nicely.

Much to my dismay, the listing disappeared before I put a bid in on it. As you may have guessed, some sneaky wonderful person in my life had paid the price to snatch it out from under me, and it magically appeared under the tree last Wednesday morning.

I finally got a chance to test it out today, and as expected the locomotives that were perfectly speed matched with the ACCUTRACK II speedometer on the NCE ran at different speeds on the Digitrax. What I didn't expect is the NCE system was faster. It uses a 13.5v DC power adapter and the Digitrax uses a 15VAC power supply, so I had expected the Digitrax track voltage to be higher, resulting in faster locomotive speeds. 

However, when I measured the track values using the AC setting on my multi-meter, I found the NCE system puts 13.8v on the track, almost a full volt more than the Digitrax which measured at 13. This causes as much as a 10 SMPH difference at the top end of the throttle, and of course different decoders and different brand locos are all affected differently. 

The Digitrax has a switch to set track voltages for N, HO and O, and the owners manual says the track voltage for N is supposed to be 12v. I expect the situation would be reversed if I was an HO guy, since according to the manual the Digitrax system puts 15v on the track in the HO setting (there is no adjustment for scale on the NCE).

So far I have also verified the locomotives that hesitate on the NCE do not show that tendency on the Digitrax, which is a real shame because I love my NCE system for its ease of use, and the WiFiTrax 31 made it super easy for me to control the trains with my cell phone. Yes, WiFi control can be done with a Digitrax system, but it's not as easy as simply replacing the interface panel. I'll probably continue to use the NCE on my home layout and just live with the hesitation since that is what I've been doing all along.

So, that is what I expected. What I didn't expect was one of my locomotives (a Kato SD70M with a TCS K1D4 decoder), which had been a problem child at the shows, also acted up on the Digitrax system at home. On the NCE system it worked just like it was supposed to, hitting the expected half and full throttle programmed speeds within a SMPH or two, but on the Digitrax system it's like I never programmed the speed tables at all. It is controllable, it is just rocket-ship fast and hits it's peak speed (as in all she can do, not the programmed full throttle speed) at half throttle. 

I will be changing that decoder, and I'll send it in to TCS to be checked, although I'm doubtful they will be able to find anything since it does work as it should on the NCE system. I will also be pulling out the sound decoder on my only sound equipped Kato locomotive because I've decided that a) sound is over-rated and b) I don't like dealing with the start-up sequence shutting the locomotive down whenever it hits a bad spot on the track. I have some NCE decoders I could use, but I really like the slow-speed characteristics of the TCS decoders, so I'll just stick with those now that I know they aren't a problem on the Digitrax system.

I have an NTRAK show coming up in February (New Bern NC from the 21st to the 23rd, you should definitely come check it out), and that's where I run my locos in consist, so I will be setting up a loop on the Digitrax to program locomotives for the next couple of months. The ones I use exclusively at home (a pair of Atlas GP7's) won't get the speed matching treatment on the Digitrax, but they run alone anyway so it doesn't really matter.

By the way, I did check out the Digitrax DC mode using address 0. It works, but not well, and I burned up an old cheap white-box train set Bachmann F9 in the process. Not a big loss, but there it is. Also, regarding the Bachmann F7A that was included in the package, it ran pretty well for about 20 minutes and then coasted to a stop. After a brief rest it ran again, for about the same amount of time. 

Either the decoder is flaky or the motor is on it's last legs, my guess is the motor is going bad. I'll have to send it back to Bachmann for repairs I guess, whenever I get around to it, or I could just order another motor to put in it. It's not like I don't have other locomotives, and I'm so concerned about this one that I'm not quite sure where it is right now. Somewhere in the train room is all I know.

I hope everyone else had a great Christmas, and we'll see you all in the New Year!