Soundtraxx in Athearn Genesis SD 70M

[woodone]

Any one know what voltage the lights are in this beast?
The original owner tried to install a DSD-AT100LC Sound Decoder in it, and gave up. The front two lights were burned out. I replaced with some 1.5 volt 30 MA. bulbs. used droping resistor 560 ohm. Lights will not light up- :curse: The original rears will, with the same resistor. Shows to be putting about 2.2 volts to the rear bulbs. They are real bright. So I disconnected them thinking that the voltage was too high. The front lights (1.5 volt) will light with a 330 ohm resistor, but when I read the voltage it was 1.8 to the bulbs. I need to get a 470 ohm resistor I guess. The local Radio Shack was out of the 470, will try to find some where else. I want the voltage at the bulb to be below 1.5 volts so they will last a day or so.
Just wondering what the original bulbs were.
Thanks in advance

 

[woodone]

Well I did find out what voltage the lights are-- 1.5 volts
They must be about 15MA because the 1.5 30MA bulbs I used needed differant resistors to keep the volts down.
Just a note for someone who runs into the same problem.

 

[Harold Cole]

!000 ohm resistors work perfect,but 560's should work also.Make sure the return is on the neg side of the diode

 

[jbaakko]

Of note, if not using a sound decoder, there's one that have the 1.5v output:
TCS A6X Decoder Eliminates Need to Use Resistor with 1.5V Bulbs | Tony's Tips at Tony's Train Exchange.