Decoder selection for Athearn Genesis and Stewart F units.

[Anonymous]

OK, I'm a little overwhelmed in trying to pick out decoders to put in my Athearn Genesis and Stewart F units.

I currently have two AB (both powered) Stewart F units and an Athearn Genesis AB set (both powered) that I am looking for decoders for. I am not planning on adding sound to any of these sets, so I'm wondering if I could get away with a 2 function decoder or if I need a 4 function....

Also the decoders are rated in amps...How do I know how many amps to plan for??

Any help or suggestions would be greatly appreciated! Sorry if i have left out any info you might need in helping me!

Thanks Guys!

[Anonymous]

The Digitrax website has a list of suggested decoders for just about all the locos out there, which is very handy -- even if you don't choose to use Digitrax, you can use their description as a guide to getting a similar decoder from another vendor with the same form-factor.

I don't have any Athearn Genesis locos, but I do have both old and new Stewart F's -- the old Kato-driven Fs use a decoder that replaces the Kato light board (same for the old Atlas/Kato engines). For Digitrax that would be the DH163KO. The new F's have a standard medium 8-pin DCC plug, so a decoder with a harness like the Digitrax DH163P (3" long harness) is recommended.

I know all the other decoder vendors make equivalents for these two, so check a site like Tony's Trains to see what's out there.

[Anonymous]

Thanks Joe.
I had been to the digitrax site and this morning had been looking at the Lenz site, which really confused me! I guess I just wasn't sure of the correct terminology for the different plug names. You helped a bunch!

[Anonymous]

I have several Stewart F units, both new and older ones with the Kato drives, and Athearn Genesis F units. I've been using/installing the NCE DA-SR decoder which I find are excellent replacements for the original boards. Also, you can get them in 4 packs for around $65. The installation in the Genesis is easier than the Stewart engines if you ask me. The DA-SR is almost identical to the Digitrax DH163KO but far cheaper. You can find the NCE decoders on ebay, I was able to score a 4 pack for $57.95, thats roughly $14.50 a decoder, and the NCE is a 4 function 1.5 amp!

[cacole]

Another good source to check for decoder compatibility is Tony's Train Exchange at http://www.tonystrains.com

[Anonymous]

dgoodlander, so are those NCE decoders direct drop in replacements for the Stewart & Athearn light boards? Is there anything I will have to do to the light bulbs on either make of the locos?

Thanks for the help!

[Anonymous]

You'll have to do some soldering -- on the Stewart and Atlas Kato-based units, the light bulb is connected to the lightboard just by being twisted around the power bus wires. In the Atlas units the light is mounted in the center of the lightboard; the Digitrax decoder I mentioned has solder pads there so you can remount it in the same place if you're not going to install separate front/rear lights (no one else has this feature). Otherwise (and on the Stewart Fs), the light has to be soldered to the front connectors on the decoder. It's pretty easy to do with a 15 - 30W soldering pencil and a good magnifying glass

At some point in the future I plan on removing the original light and going with directional lights, but for now it works fine..

One thing I found on the Stewart/Kato Fs is that there's a support on the original light board for the back of the small tube that directs the light towards the forward lens and keeps it from illuminating out the portholes. The decoder boards don't have this support, so I improvised by using CA glue to glue the light tube to the front support, and put a large-enough piece of shrink tubing on the back to cover (and support) the little bit of the bulb that sticks out the back of the tube. The heat of the bulb is just enough to shrink the wrap to give it a good seal.