Which DCC decoder for my Athearn Genesis F7A G1504

Model Railroader Electronics and DCC
1

I would like to add DCC to an Athearn Genesis F7A G1504A,

This is the model which does not have the 8 pin adaptor and requires a board change.

This engine has two forward lights, one, the top light is red and only comes on in reverse. The second light mounted below the first appears to be a double light headlight and only comes on when the engine goes forward, does not flash just a steady light, not sure why Athearn is using a dual bulb headlight.

Which decoder do I need to use for this engine. The bulbs are both 1.5V 12-15ma rated. Will I need to add resistors?

2

Train control system suggests an A4X decoder. http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Athearn/Genesis_F3A/athearn-genesis-f3a-a4x-decoder-installation.html

You do need resistors for any bulb or LED under 14 volts. I would try a 1K 1/4 watt to start. Wire the red bulb to the rear light pads.

Pete

3

I’m curious about the number boards. Do they light up, and if so, are they on whether forward or reverse? If so, how would you wire that?

4

These number boards do not light up. Surprises me, but no they do not light up.

5

I’ve done several Genesis F units. I like the NCE DA-SR and Digitrax DH165A0 decoder for these installations. While they both still require dropping resistors for the 1.5V lamps, the slick drop in replacement board makes the installation neat. The NCE directions have tables to help one get the proper valued resistor. The hardest part is to NOT pull the headlamp wires and inadvertently pull them out of their sockets. They are pretty hard to get back in and the wires strung behind the cab interiors properly.

6

Athearn matched headlights to the prototype. So if your prototype had dual bulbs then so will the model. I’ve got one with dual bulbs top and bottom. Red for reverse like yours but the top housing also has a white bulb that is a Mars lamp when the train is going forward.

7

Don’t stop at just installing the decoder and resistors. Replace the bulbs while you have the unit apart. The bulbs shipped in the Genesis F units are notorious for not lasting long in service.

Like Texas Zepher, I go with either a NCE DASR or a Digitrax DH165A0 for these installations, then I replace the existing bulbs with Miniatronics 1.5V 15 mA bulbs. I use a 750 Ohm, 1/4 Watt resistor with each bulb.