Recently I’ve been getting emails from folks looking for posts on specific topics. Currently there are over 400 posts on various topics on this website. However, only the 40 most recent posts are shown on the main page. While you can browse through the archive of posts that could take a while and there is a simpler way. In the upper right hand corner of each page there is a search box. To find posts on a specific topic all you need to do is type a subject into the search box and hit the enter button on your computer. The WordPress program will do a search and display all the related posts. Give it a try, it really works!
When I took on the assignment of being the DCC Corner columnist for Model Railroader magazine I decided it was time to start a website where I could post additional information that I just didn’t have room for in the monthly column–so here we are.
The posts here are organized with the 20 most recent posts in each category (DCC and Layout) appearing on the front page. The rest rotate into the post archive as new ones are posted. By clicking on the post archive menu option you can browse through all previous posts. There are currently over 300 posts so unless you’ve been here from the start you have some reading to do. If you are looking for a specific post or topic you can search the archive using the search box at the top of the page.
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One of the great features that Soundtraxx carried over from the Tsunami to the Econami and Tsunami2 decoders is the 7-band equalizer. This is a neat feature that allows you to customize the sound output frequencies of the decoder to better match the capabilities of your speaker. Sound is generated by pushing air out from the speaker cone. The larger the cone the more air you can move and those low frequency bass tones that we love to hear are located down in the lower frequency range below about 500Hz. So speaker size is an important consideration if you want the best bass sounds. However, we just can’t squeeze a 4″ speaker into an HO switcher much less an N-scale locomotive. This creates trade offs for getting the best sound.
One common method modelers resort to is turning up the volume in hopes of getting more bass. However this doesn’t really work all that well since it can create distortion. If a speaker is too small to actually move enough air to produce the bass you want, turning up the volume can result in an effect called clipping–we hear it as crackling sounds. The 7-band equalizer gives you the ability to alter the frequencies put out by the decoder so you can turn up the volume without leading to clipping and distortion.
So how does that work? The 7-band equalizer is similar to the sliders on many stereo systems that allow you to alter the output of given frequencies in 7 distinct frequency bands or ranges. Each band can be set through a range of 0-255 with 127 being “0 dB”. A value of 255 gives you +12 dB and 0 gives you -12dB. These values are programmed into CVs 226-232. Notice in the figure that the frequencies overlap, so when you change one it will affect adjacent ranges, requiring a stepwise approach to get it just right.
Another useful feature is that Soundtraxx includes preset values for 4 sizes of speakers. Programming a value of 1-4 into CV 225 will set the frequency range values to correspond to speakers ranging from <1″ to >4″ in diameter. A value of 7 will allow you to use the custom values entered in CVs 226-232. As a test I set the CV settings to correspond to the micro speaker values to see how they would work with a 13×18 mm sugar cube speaker. I then started making slight modifications to the CV values to see if I could improve on the preset values–I couldn’t, so I guess Soundtraxx did a pretty good job. So once you start installing new Soundtraxx decoders don’t forget to at least set CV 225 to one of the preset speaker sizes.
Since sound decoders are such a popular topic, let’s talk a little about speakers. When installing more than one speaker in a locomotive it is important that they be wired together so that their polarity is the same. If you wire them in reverse polarity they will produce sound waves that are out of phase resulting in poor sound quality.
Although some speakers have polarity markings on them next to the solder contacts. Note that the speaker in the photo does have polarity markings below the ohm and watt ratings, but many do not. If the speakers are both the same type and from the same maker then it is usually safe to assume they have the same polarity contacts. However if they come from different sources that is not a safe assumption. So how can you tell which contact is positive and which is negative?
The easiest way to check polarity is to take a plain old 9 volt battery and connect a couple test leads to it. Next touch one lead to one contact on the speaker and the other lead to the other contact while watching the speaker diaphragm. If the diaphragm pushes outward then you have the correct polarity, so note which leads from the battery are positive and negative and mark that on the speaker. Repeat this test for the other speaker(s) and you are ready to wire them up.
For more tips on how to install speakers see the May 2016 DCC Corner column. I’ll have a lot more to say about speaker selection and wiring, so dig out you back issue.
In my October 2017 DCC Corner column I showed how I installed a LokSound Select decoder and sugar cube speaker in a Kato NW2. Today I want to give you all a chance to see and hear the finished fortunately the new Streamlined Backshop dual speaker enclosure that fits inside a cab roof was not available so I used the standard version for the NW2. I’ll be using the dual speaker version of this enclosure in the April 2018 DCC Corner column to replace the original Lenz built decoder in an Atlas FM H16-44 locomotive.
I think you’re really going to love these new enclosures since they fit the curvature of a cab roof making them virtually invisible from the outside. I have used several of the 11×15 mm speakers in past installations so I am anxious to hear what a pair of them will sound like.
But let’s get back to the NW2. In this loco I had to cut out a chunk of the chassis to make a spot for the decoder. I ended up installing the 11×15 mm speaker in the cab and if you know where to look you can see part of it through the front window. However it is no more obtrusive than the black plastic light enclosure that fills half the cabs on my BLI SW7’s. OK, lets stream the video.
The RRAmpmeter from DCC Specialties is a great device for measuring track voltage and amperage. Because the DCC signal has such a high frequency your everyday volt ohm meter doesn’t provide accurate values but the RRAmpmeter is designed specifically for that job.
However one thing to be aware of is that you do have to have a load on the track when using it. A single locomotive sitting on the tracks may not be enough of a load for consistently reliable results. However the load can be something as simple as a 12 volt automobile tail light bulb clipped to the tracks. Be careful in choosing the bulb since a large taillight bulb like the #1156 may pull in so much current that it can shut down a small booster or command station. The reason being that light bulbs draw as much as 10 times their rated current when they are cold compared to after they have been on a short while.
Another thing to watch out for is the heat generated by a bulb–don’t let the light bulb flop over onto foam scenery. I did just that while I was taking a photo and it got hot enough to actually melt a hole in my foam scenery! I don’t know whether it could have gotten hot enough to start a fire if left there long enough, but I learned my lesson from that experience.
For convenience, you can quickly make up a fixture with the light bulb soldered to two wires having alligator clips on their ends. Attach it to the tracks you are measuring or clip it to the contacts on the opposite end of the RRAmpmeter from the track contacts. This arrangement makes it much easier to move the RRAmpmeter along the tracks making measurements as you go.
When measuring track amperage you must have the RRAmpmeter wired in line with the track feeders so it is basically a stationary measurement device for amperage. If you have your layout broken into a number of blocks using a PM42 or PSX4, you can move the RRAmpmeter from one to the other but that will get old fast. Some folks mount the RRAmpmeter into the fascia or adjacent to the booster to montior voltage and amperage for all the blocks powered by the specific booster. In that configuration the standard RRAmpmeter is rated at 23 volts and 10 amps–a more robust unit can be ordered that can take up to 20 amps.
If you have several boosters it get expensive to purchase a RRAmpmeter for each of them. There are plans available on the internet for building circuits that allow you to measure DCC voltage and amperage using a standard volt ohm meter. You also can buy standalone meters for voltage and amperage to install with these circuits. Having a way to reliably measure track voltage and amperage is a useful tool when you need to debug a problem.
In my September 2017 DCC Corner column I talked about using a common between boosters on Digitrax and NCE command stations and boosters. This is especially important when dealing with both centralized and decentralized booster installations. A centralized booster design is where all the boosters and command station are located together. A distributed design is just the opposite, with boosters located around the layout near the tracks they power.
I used to argue in favor of lining up the command station and all the boosters right next to one another, and in some cases I would still suggest doing it. If you have a layout where the command station and boosters can be placed in a central location and the power buses fan out from there to the tracks they serve, with minimal overlap, then that would be a good option. With all the components sitting next to one another it is easy to interconnect them, their wiring is kept short, plus it’s easy to trouble shoot when you can see any lights, and hear any warning and error sounds. The down side comes when you have to run parallel power buses next to one another to get from the central location out to all the track blocks on the layout. This results in overly long wire runs, increasing the chances of inductance related issues.
Now let’s look at the distributed arrangement. Many layouts have a pretty linear design with blocks located one after the other. If you run all your power buses out from a central point you’d have to run several of them alongside one another for at least part of the distance and that would be a waste of wire, and require some long runs. But what if you put a booster at the junction of two of those blocks? That way there would be no overlap and minimize power bus lengths. If you have two levels then you could run two power buses down to the lower lever and connect to two blocks there. Again, you’d have little overlap and shorter bus runs. You could locate your boosters at several points around the layout in this configuration and greatly reduce the lengths of all your runs. But how about interconnecting the command station and boosters?
When connecting boosters to a command station you have to have a cable, usually a flat telephone type cable, running between them. This cable sends out the basic low power DCC signal from the command station so the booster can boost it to final track power levels. Most manufacturers also suggest having a common wire running between them–this serves as a reference so that you don’t have problems crossing between power blocks, and autoreversing. So you would have to run a booster network around the layout but that’s a lot cheaper and easier than those longer power buses. And a single 14-12 ga wire can be used as the common wire. For optimal performance and to minimize electronic interference you would want to keep about 6″ between this network and any power bus running near it.
In the final analysis the important consideration in deciding which approach to use really comes down to picking the one that will give you the shortest power bus runs with as little overlap as possible.
For the next couple months I am going to be preoccupied with wrapping up the final chapters of my new book on wiring projects for model railroads. As of today I have submitted 5 of the 16 chapters and my final deadline is December 31, 2017. The good news is I already have written the text and just need to shoot another 150 or so photographs and do some final text edits. On the downside there are two chapters that I haven’t actually done any physical construction on and they need some real work. Consequently you probably will only see one post a week from me until this thing is done. In the meantime here’s something for anyone new to DCC or considering a system purchase.
I am constantly being asked what’s the best DCC system for me? However that is a question I really can’t answer–I can only make some suggestions. First let’s talk about which brand to get. Most of the DCC systems available today offer pretty similar, basic capabilities so that really isn’t an issue. My suggestion is to go with the brand most of your friends or local club use. Why, well if you are going to operate on their layouts then you’ll need a compatible throttle. Also, if you need help with something you’ll have a better chance of finding a local DCC expert to answer your questions and help debug problems. In my area 99% use the same system, primarily because the local club uses it. Of course if you are a lone wolf out by yourself somewhere then go with the system that offers the best support capabilities in your area, which probably means a knowledgable local dealer.
Another consideration is the size of your layout and scale. Bigger layouts usually mean more trains. Bigger scales usually mean locomotives that need more power. So if you are building a basement empire make sure you can get all the power and accessories you will need for it. At the very least make sure additional boosters and throttle plug-in panels are available. The more accessories a company offers, the easier it will be to expand in the future.
Choose a system with a throttle that is comfortable to use and instructions that are easy to understand. Throttles vary in size, shape, and capability so it is important to find one you will be comfortable with. This may mean visiting some layouts and asking some questions but do it, you don’t want to choose the wrong system and have to start over. You might think that inline forums are a good suorce of information but that may not be true. Often the folks on these sites are either proponents of a specific system or are there with a questin or complaint. So take any glowing recommendations or overly negative comments with a grain a salt.
Finally, go to the website of the manufacturers you are considering and download their manuals. Also be aware of whether or not they address questions like whether a system ground should be used, or how to deal with special wiring situations. If you understand one system’s manual a lot better than another then maybe that is telling you something. Keep in mind that a lot of this stuff may seem very technical at first, but a lot of that comes from a lack of familiarity with the terminology involved.
As a wrapup to my posts on sound decoders and function remapping, let me tell you the solution I have arrived at. First, my kudos to David and the rest of you who are trying to adjust similar functions so they coexist and also those who are remapping functions. I also applaud those who use the same types of decoders in locomotives to be used in a consist–that greatly simplifies the task of dealing with mismatches of function. So here’s my solution to these problems.
Since most of the folks in my area who make the monthly rounds of operating sessions bring along their own Digitrax utility throttles I have to take that into consideration. These throttles have access to all the functions from F0-F12, however for those above F6 you have to hold down the Shift button to get to them. This is a real limitation because it is difficult to press the Shift and press another button simultaneously while also running a train, uncoupling cars, and manipulating a set of car cards. Consequently I wanted to have the most commonly used functions mapped to F0-F6. So here is my lineup.
First, I made up a table listing the default function assignments for the five brands of sound decoders I own. That way I was able to quickly pick out which ones I would leave in their default positions and which needed to be remapped. It also made it easier to decide on a common set of functions. I left functions F0-F2 on their default settings since these are essentially standard for all decoders and throttles. I then assigned the grade crossing signal to F3, which seemed to be a natural location next to the horn/whistle at F2.
F4 can have a number of different functions depending on the decoder brand so I assigned it to the switching mode. F5 is often set for the dynamic brake on diesels and blow down on steam so that’s what I set if for in my scheme, for all but Digitrax which can’t easily be changed. The big function left was the brake function which varies greatly among decoders so I moved it to F6. Although I don’t expect it to be used often I moved the headlight dimming function to F7 and left F8 as the mute. F9 and F10 were assigned the notch up and down function on diesels and left open on steam. Since that covered all the functions I wanted, I left the rest alone.
Where possible I used the automatic functions to activate brake squeal and to use Rule17 lighting as supported. I did not activate the automatic bell and whistle when the locomotive direction is changed but I do have the bell set to ring when the grade crossing signal is used. I make all these changes when I install a new decoder or purchase a new locomotive. Like some of you I use car cards, including a locomotive card that has a list of the function assignments on it. That way operators have that information available when they receive a train assignment.
Making these decisions only took a few minutes but making the programming changes was a bit more protracted. However, DecoderPro speeds the process with its point and click interface. Having the major sound functions assigned to the same buttons on all my locomotives (except the one Digitrax decoder in my ALCO RS1) makes it easier to actually use the sounds prototypically. It also alleviates the frustration of not knowing which button to press when you want something to happen and makes cheat sheets a thing of the past.
Fortunately most of my sound decoders are WOWSound and Soundtraxx which makes my job easier. I only have 2 LokSound decoders and one Digitrax. On the BLI side I have 2 diesel switchers and 3 steamers so that won’t be too bad either. I have been working more with the LokSound decoders and I agree with those who have said they are confusing to remap using DecoderPro. I am putting together information on the LokSound sound slots and will have more to say on that later. I will say they are making an attempt to standardize them among sound projects. I am planning an article for my DCC Corner column on programming LokSound decoders using both DecoderPro and the LokProgrammer so I can’t go too far without running afoul of my agreement to publish new material there first.
The LokSound decoders are different in more ways than one. For example there is no grade crossing horn sequence so I am just substituting a short horn on F3. And you cannot simply remap sound button assignments with a Digitrax sound decoder–you have to go into the sound project and modify it internally. So that one decoder probably will not get modified anytime soon. You have to be flexible when trying to standardize a whole fleet of locos with dissimilar decoders because of these differences. Sometimes that’s the best you can do. Plus the sounds that are most important to me may not be the same for you. Give this process a try and see if it works for you.
Don’s comment to my post on sound decoders brings up the topic of function (re)mapping. As Don pointed out some throttles cannot access the extended range of functions now available in some DCC decoders. There is another issue here as well, as I all too often hear from many modelers, they get frustrated because manufacturers all too often put the same function on different control buttons. Don’s solution was to upgrade to a throttle which can access all functions, but that doesn’t solve the second problem. There is of course another option—function remapping.
Of course one way around the second problem is to buy all your decoders from the same manufacturer and that way they would all behave the same, which is one solution Don alluded to. However now that locomotive manufacturers are offering their models with decoders already installed and they often change the decoder maker every few years, it makes it difficult to keep a “clean” roster. And of course the manufacturers are always coming up with some new feature or sound package to entice you to buy their products.
But what about Don’s problem of having too few function button? Throttles typically are equipped with only 8-10 buttons limiting how many of the 28 NMRA sanctioned functions you can control. Some of these throttles offer ways to expand the number of functions using the equivalent of a shift key, but I find it awkward to try and hold down two keys to access a function while also trying to operate a locomotive. TCS has added a kink to this by creating dual function buttons that control sound mode and light mode functions. But to toggle between them you have to hit the “8” button twice before hitting the desired function key. So in the end folks usually just use the horn and bell functions and ignore the rest.
The work around is twofold. First, the manufacturers have gone to adding automated functions. These include sounds like brake squeal, brake release sounds, automated crossing logic, and sounds that play when direction is changed. But again some decoders will have this while others do not. So what kind of work around is there? How about function remapping! This capability has been around since the early mobile decoders but really didn’t get much use until sound came along. The idea behind this feature is to change the functions assigned to the various buttons on your throttles so that you have a consistent set that can be accessed on all your throttles.
So how do you do that? First make up a spreadsheet of all the functions offered on your various decoders. Then circle all those that are controlled by the same button. Next go through the rest of the functions and pick out those that you would like to add to your consistent set. Finally use DecoderPro or your throttle to reprogram all your decoders to achieve this. However, this is another place where you will run into roadblocks.
Most decoders are limited as to which functions can be remapped to certain buttons. For example you typically can’t move the lights, bell, and whistle from the 0, 1, and 2 buttons or at least not move them far. The same is true for other groups of functions. You might be able to piece together a set of functions that will work for most of your decoders and throttles, but not all of them. With the increasing number of supported functions in decoders it is becoming increasingly more difficult to find enough buttons to remap them to. This is especially true for folks who depend on utility throttles. Econami decoders are now offering a way around this limitation–using their new function mapping capability you can remap any function to any button. I know you want to know more about this neat feature, so I’ll save that for another post coming soon.
No matter what scale you model there are several factors to consider when deciding which sound decoder to purchase. First you need to see if anyone actually makes a decoder that will fit, especially if you model in Z or N scale. With the introduction of sugar cube speakers there are more models in which sound installation may be possible. The main limitation really is a matter of whether there is a decoder that will fit. While sound decoders will fit in many N scale steam locomotive tenders, many diesels remain a challenge. Streamlined Backshop (www.sbs4dcc.com) has a fairly comprehensive list of decoders for various scales.
There is a much wider selection of sound decoders available for HO scale and larger models, and installation is generally easier. Many manufacturers offer plug and play versions of their decoders that may only require plugging in the decoder, installing a speaker, and hitting the tracks. TCS offers kits containing their WOWSound decoder, a motherboard, speaker, and speaker enclosure designed for specific locomotive models. These are a great option for anyone who has never installed a sound decoder and practically guarantee a perfect fit.
At one time stall currents were a concern when selecting a decoder. However most models made today have very efficient motors that draw under 1/2 amp and most decoders now can safely provide 1 amp operating current. If you have older motors made before about the year 2000 it is a good idea to see how much current it draws. As a guide open frame motors generally draw more current than can motors.
The final concern is whether or not the available decoders actually offer the sounds package you need for a given locomotive. On their website Soundtraxx has a great page listing many of the types of steam and diesel locomotives and the proper sound package for them. There is a listing of the various prime movers used in diesel locomotives and an excellent one on the types of horns many railroads used. Digitrax, Loksound, Soundtraxx, and TCS all have pages on their websites where you can listen to clips of the sound packages they offer. So finding the right decoder is mainly a matter of doing a little research.