Locomotive Electronic Upgrades

As I start building my layout, getting the locomotive and rolling stock fleet up to standards is an important step. In terms of motive power, I have a total of 41 locomotives. Most of them are Athearn blue box engines that I've been moving with me for the past 30 years. In recent years, I have been buying higher end brands like Kato, Intermountain, MTH, and Athearn Genesis.

In order to use the fleet on the layout, several things need to be done to each engine:

• Properly gauging the couplers, replacing the existing ones if necessary
• Installing a DCC decoder in each locomotive
• Adding lighting - basic headlights vs. more elaborate lighting
• Considering extra features like sound and keep-alive capability

As with everything in model railroading, you can spend a little or spend a lot. In my case, I need to look at the original cost of the engine and the likelihood that it gets replaced in the future. My prioritization is covered in the rest of the article and your wallet may make you choose differently than I did. 

DCC Decoder

In order to run a locomotive on a DCC layout, you need to put in a DCC decoder. While you can run an engine on some DCC layouts (Digitrax supports it) without a decoder, there are some drawbacks:

• The engine will emit a high-pitched hum when the engine is idle on the track. The hum decreases as the throttle is turned up. 
• Any analog locomotive on the layout will respond at the same time when you have locomotive 0000 selected in DCC. 

I have enough decoders available for most of the fleet, but I've got a few additional engines that I don't have decoders for yet. Because I've had good luck with them and they have a great warranty service department, I plan to stick with Digitrax for my non-sound decoders. 

When choosing a decoder, you need to determine the form factor (overall size) and how many function outputs you need. You can also look at the power output, which will vary between 1-1.5 amps for HO and N scale decoders. Large scale decoders push out more power, of course.

Each function output is used to control a function on the locomotive, which for conversions like I'm doing is lighting. Based on my plan for installing lights, I will need these function outputs:

• Headlight (forward and reverse) - uses one output, since the decoder handles the forward and reverse on its own. This is normally labeled as F0F (function zero - forward). 
• Marker lights - these essentially are just additional headlights that turn on when the engine is going in reverse. They will get wired into the F0R (function zero - reverse) circuit.  
• Ditch lights - These can be installed as additional headlights on F0, or you can separate them into a separate function if you want to control them independently. Since I have the available function output, I will put them on F1. 

Digitrax offers these decoders:

• DH126D (1.5 amp output with 2 function outputs)
• DH166D (1.5 amp output with 4 function outputs)

The DH166D supports Back EMF, which helps stabilize the locomotive's speed. For more details, read this article. For the two switch engines I have, the DN136 (3 function outputs) is a smaller decoder to fit into cramped spaces. I'll explain the need for function outputs in the next section covering lighting. 

Lighting

Lights on a locomotive are the next priority. Lights can quickly tell you if you have successfully acquired the locomotive on your throttle. If directional lighting is set up, you can easily tell which way the engine is going to go when you turn up the throttle. There are four types of lights that can be added to a locomotive. 

For starters, locomotives have headlights in both the front and the rear. The decoder can automatically switch between the front and rear lights based on the direction of the locomotive.

Ditch lights are the lower lights in the front (and maybe in the rear) down at approximately car level. They were added to make the train more visible at crossings. In some locomotives, the ditch lights alternate when the horn is sounded or when the bell is ringing, adding to their visibility. Some of these ditch lights are mounted above the front walkway, others are mounted below. If you want to be accurate, use a site like RailPictures.net to research the railroad or the engine type you are modeling.

Marker lights are colored lights on the front of the locomotive. The most common use of these lights today is on passenger trains when the engine is running at the end of the train, the red lights are used to indicate the engine is the end of the train. In the past, marker lights were used for describing what type of train was coming. Older Canadian locomotives had three marker lights over each number board, as shown in this picture:

However, the most recent builds of Canadian locomotives omit these lights. 

For my fleet, these are the rules I'm going to follow:

• Headlights in all locomotives
• Taillights will be reserved for higher quality locomotives (Kato, Genesis)
• Ditch lights will be added to the Canadian locomotives (BC Rail, CP, CN) and the higher quality locomotives
• Red marker lights will be installed in Amtrak/VIA Rail P42 to support push/pull operations

Based on research, the best place to get headlight upgrades is the MONSTER LED package on eBay, which includes 9 headlight-sized LEDs and 6 ditch light surface-mount LEDs for $32.25 including shipping. Here's the math:

• 2 headlights, 2 taillights, 2 ditchlights: $13.50
• 2 headlights only: $4.50
• 2 headlights and 2 ditch lights: $9.00
• Red marker lights: $1.25 each

The majority of locomotives I own cost  between $30-$50 to purchase and may get replaced in the future. For my better quality Athearn Genesis and Kato locomotives, I am more willing to put some money into them.

Certain locomotives, such as switch engines, might have rotating beacons on the top. Older engines had Mars lights, which created a figure eight pattern in front of the locomotive. Some decoders will support this blinking or strobing effect. Canadian Pacific and BNSF do not use these any longer, although some newer SD40-3 rebuilds from Canadian Pacific do have them for remote control warning purposes.  

Sound

Until I got my first sound-equipped locomotive, I never saw the point of putting sound into a locomotive. However, with the major improvements in sound quality and the ease of installation, I've changed my mind. That said, adding sound to a locomotive, either as part of the initial purchase or as an add-on, is still a non-trivial purchase if you're on a budget. As an example, the newest Rapido F40PH-2D rebuild costs $199.99 without sound and $279.99 with sound. (ModelTrainStuff prices)

Since I'm a Digitrax user, I included their products along with ESU LokSound and Soundtraxx, which were recommended by people who do lots of these installations.

ESU offers the LokSound Select product in three form factors for about 87.99. You need to add a speaker (available for 7.99) and can add the optional PowerPack capacitor (available for 7.99) to keep the sound going between track power dead spots. They have a higher end product called LokSound 4.0, but from my research, it's got way more sounds than I could ever use. ESU also has the LokSound Programmer product (143.99), which is used to change the sounds and features of its decoders. This is not something I would buy unless I got to the point of adding lots of sound decoders. Most basic settings can be changed using configuration variables. One other note: a number of manufacturers (including Rapido and Intermountain) are using LokSound decoders in their sound-equipped locomotives.  

Soundtraxx has two product lines: Econami and Tsunami 2. The Econami line, as the name suggests, is the lower priced brand. There are three products in this line:

• ECO-100: 1 watt amplifier, 4 decoder functions
• ECO-200: 2 watt amplifier, 6 decoder functions
• ECO-PNP: 2 watt amplifier, 6 decoder functions - plug-and-play board replacement

The pricing I found on eBay was odd. The ECO-100 was 71.96, the ECO-200 was 67.96, and the ECO-PNP was 63.96. Given that the ECO-200 is a better product, the pricing seems out of whack to me. The Tsunami products range in price from 87.96 to 103.96 and include a better processor than the Econami line. 

Digitrax has an 8 bit sound decoder (SDH166D, 44.49) and a 16 bit sound decoder (SDXH166D, 62.95). In watching YouTube videos of these installed in locomotives, the sound quality had a very "tinny" quality to it, but it's entirely possible that the quality of the sound was based on the recording and not the device itself.  For $62.95, it might be worth experimenting with to hear the quality first hand. 

There are also products available from TCS in the WOWSound line, but I did not find many people using these products, besides the TCS Keep-Alive product. The pricing on these decoders is also at the high level, around $100 per decoder.

For my fleet, I will not be installing sound in any Athearn blue box locomotive. It's simply not worth the money. The only one I might add sound to is a GP38-2 that was my first detailing project. In general, the sound will be restricted to the better quality locomotives. In addition, I typically buy locomotives in pairs with the eventual goal of having all mainline trains pulled by two locomotives faced back-to-back to remove the need to turn the locomotives. When I do this, I will add sound to one of the locomotives in the pair.

When I get further along in the upgrade process, I will probably purchase one of each of the Digitrax, Econami, and LokSound Select decoders to be able to give them an apples-to-apples comparison, which I have not really found in my research so far. 

Keep-Alive Capability

One of the newer features that you can put into a locomotive, especially one with sound, is a keep alive enhancement. They all consist of a capacitor that automatically charges while the locomotive is on the track. If the power drops out, the capacitor's power is used to keep the sound, lights, and even the engine moving. If you have particularly dirty or bad track, these are helpful devices to add. One of the main reasons to keep the power to the decoder is to avoid the engine going through its "startup sound" that happens as soon as the engine gets power (or gets acquired through DCC).

The keep alive components I found were:

• Digitrax Power Extender - only works with Digitrax sound decoders - around $20-$23
• ESU Power Pack - $7.99 for two capacitors
• TCS Keep Alive - works with all decoders - around $25-$31

Given the low relative cost of the keep alive function to the sound board itself, this seems like an easy choice to smooth out locomotive operation.