athearn LED upgrade help

[Trainman440]

Hi, I know that a lot of people hate the athearn incandescent bulbs, and did the switch. The lights on my f7 burnt out(I checked the voltage output on the soundtraxx decoder with a multimeter and apparently it was 2.6 volts! ) I want to install 3 volt smd leds as a replacement. How do you install a 3 volt led into a 2.6/1.5 volt decoder lighting output? 

[skagitrailbird]

Did you say Athearn F7? Unless I ammistaken the headlight opening is much larger than a surface mount LED. Why not use a 5mm LED?

No tatter what LED you use, if you still have a DC power pack, try seeing if the chosen LED will light up to your satisfaction on the voltage of the selected decoder lighting output. If not, perhaps there is another output on the decoder with 3v or more. if much more, put a resistor in series with the LED.

 

[Trainman440]

Roger,

Check out the Athearn genesis santa fe f7. The headlight is 2  1mm holes. Besides, I currently don't have any 5mm leds. 

All of the decoder lighting outputs are about 2.6 volts. At 2.6 volts, the Leds are too dim for my tastes. (You can barely see it lit). I heard many people did it before, I just want to see what they did. As far as I know, there aren't any lower than 3 volts leds on the market.

Do I have to replace the quality soundtraxx decoder?

[rrinker]

 You just have to take power from a different point on the decoder. There are full voltage (12-14) outputs as well as the low power ones for the light bulbs. Witht he full power outputs you will need 1K or more resistors on each LED. !K is a perfectly safe starting point, but some of the white LEDs, particularly the sufrace mount types, are VERY bright even with just 10ma or so that flows with a 1K resistor, and you may have to go higher.

                       --Randy