First, an update. I have added a page of action and scenery photos under the Union Pacific section. Many of these date from the film days, but I’ve also added a few of my more recent digital moments. See here for that…
Okay. You may recall my recent post about my new foray into the world of Digital Command Control. I have close to a dozen locomotives fitted out now, including a Kato P-42 for Amtrak ops (that one was like doing brain surgery!). Although still green as grass in this area, I’ve stumbled around enough to have a couple of observations and even a suggestion or two.
First up, I have learned the hard way to read the documentation carefully. For instance, the Digitrax DH-126 decoder, though FX-3 capable, only has two function outputs. These are by default the front and rear headlights. If you are expecting to use one to dress up a locomotive with, say, ditch lights, think again. (but, see below) In most cases you’ll want to go with a minimum of their DH-166.
Next, I’ve discovered that if you google around long enough, there is a wealth of helpful information on the subject. So far I’ve been able to answer every question I’ve had, eventually. Also, Digitrax’s helpdesk people are super helpful and responsive. I don’t have any experience with the others, although Kato’s online docos are indispensable for things like DCC conversion / installation steps.
I have also happily discovered that my scheme of essentially bolting a DCC system onto my block-control layout has certain advantages. For instance, if you’ve created a consist for a long train that utilizes remote helpers, there are times when it’s very useful to be able to kill the power to one of the sets of locomotives. Without that, your only option seems to be to delete the consist and recreate it later. It’s saved my bacon a few times already.
And now for my Hint du Jour. It turns out that you can indeed use the inexpensive DH-126 decoder to operate ditch lights (or other secondary lights) after all. Here’s how. Let’s take for example a DCC-ready Athearn unit, or even a blue-box Athearn that you’ve dropped a control board into. In my experience, unless your loco is a switcher, there is almost never a time when you’d actually use the rear headlights– or want to. That means, these lights are available for relocation to someplace more useful, such as the FRONT of the locomotive. There are of course two categories of implication: physical, and digital. Well, for the physical part, just run the lights up front to your desired installation, drill whatever holes you need, and fit them in place. (I discovered that the stock wires were a smidge too short, and had to really be creative with my wire routing to get them to reach. But you can always extend them.) For the digital part, I found a set of Configuration Variable codes posted by a helpful gent that re-map the controls so that they work going forward, not reverse (technically, you control them manually). Here are the codes.
CV33 = 001 / CV37 = 002 / CV41 = 002 / CV45 = 064
CV34 = 001 / CV38 = 004 / CV42 = 001 / CV46 = 128
CV35 = 004 / CV39 = 024 / CV43 = 016
CV36 = 008 / CV40 = 000 / CV44 = 032
This method is pretty much right out of the Digitrax manual on pages 51-52, by the way. On our 2-output decoder, this puts your newly-relocated ditch lights on the F3 button. Given our situation I’m pretty sure we don’t need all of those programming changes, but I’m not quite conversant enough yet to know which ones to ignore, so I just do them all…
I converted one of my AC4400s to have operating ditch lights in the course of watching a couple of episodes of The Office, including drilling out the stock Athearn ditch light boxes. I am pretty sure it’ll be slightly more involved when using deck-mounted light holders, but the principle is the same.