Athearn F7A and DCC

[Anonymous]

Hello!

Before I post I would just like to thank you all for all of the fabulous info that I have gleened as I lurked here for several weeks. My 2 boys and I are so very excited to be doing this (Dad is probably more excited at the moment!)

I have 3 C&NW F7As that I have bought and detailed out with road numbers, breaks, windsheilds and the like. We have decided on going the DCC (Digitrak) route as the local club here uses it. I popped open the top (413[:D]) and found NOTHING like I expected.

There is a solid metal par that runs across the top delivering the power to the motor to complete the circuit. Where the heck do I put the chip? What if I want to put in one of those Tsunami chips when they come out? I don't see how I can get the space to do this. Do I have to /gulp go the BLI route? Those are 209 a pop and I really don't want to go that route if I don't have to.

My layout is going to consist of 4 towns on the old Northwestern Passenger line of the C&NW in 1978ish. I know I will need 3 F7As with DCC, only question is do I have to go buy 3 new ones, or is there a kit I can put into my current locomotives.

Thank you all so much,
Andrew

[rrinker]

Look at the Digitrax DH163AT, or else a TCS T1 and one of Digitrax's DHAT harnesses (cheaper but every bit as good). The harness allows solderless installation in an Athearn blue-box locomotive (which must be what you have, not the Genesis series). There's actually plenty of clearance between the top of the motor and the shell for the decoder to fit. And yes, the Digitrax harness will work on the TCS decoder - the TCS decoder has a 9-pin JST plug on it, and the DHAT harness is 9-pin JST to special Athearn clips.

--Randy

[Anonymous]

The decoder eliminates the bar you see across the top of the motor. You can buy the AT harness for solderless Athearn applications. I just hardwire a Digitrax 9-pin harness to the locomotive. It does require some soldering. Remove the long bar from the top of the motor. The orange wire solders to the top motor brush clip, grey goes to the bottom. Remove the clips to solder the wire to them. You'll have to remove the motor anyway. The botttom brush clip has tabs that contact the frame for electrical pickup.
Remove these and put a piece of tape under the motor to assure it is isolated from the frame. Solder a piece of wire to where the long bar made contact with both trucks. The red decoder wire will solder to either of these places also. The black decoder wire is attached to the frame. Some people drill and tap a hole and put themwire under a scrrew. Others solder the black wire to themetal headlight bracket close to where it contacts the frame. I solderthe black wire to the other side of the truck (left rail I think) and solderan extra wire to the other truck. This helps keep electrical contacr better than the other methods. You have a blue wire that is common for lights, etc. The white wire powers the front headlight. The yellow wire is function2 (usually the rear light). If you have more functions they are the other wires on the harness. It's not really that difficuot to do. One or two units will get you familiar with the setup. Hope this helps.

[bpickering]

Digitrax has (generic) installation instructions for Athearn locos at:

http://www.digitrax.com/appnote_dash9app.php

Per this page:
Note: This installation is based on installing a Digitrax DH140 decoder in an Athearn Dash 9-44CW. The process is similar for any Digitrax mobile decoder with wires. The instructions are also easily applicable for any Athearn locomotive.

Good luck. I'm about to embark on installing a bunch of decoders too, including two in Athearn locos. (It's either that, or figure out how to explain to a four-year-old, "We can have those locos <DCC already installed>, but only one of these <no decoder yet>" Fortunately, his favorite one right now is the Veranda Turbine with SOUND!!!!!).

Brian Pickering

[mgruber]

Go to Model Railroaders home page and click on controls & electrical under the modeling section and theres an artical showing how to wire in a dcc decoder for Athearn diesels.