I have an HO scale Atlas Master series GP-38 loco, which comes with their basic 2 function decoder. The headlight is quite dim for my taste. I have tried moving the bulb closer to the piece of plastic that is supposed to 'carry the light' to the headlights and number boards. Didn't make much difference. Would like to keep using the decoder as long as it works. The info sheet in the box from Atlas indicates that the two function outputs have a current rating of 200mA.
What are my options? If I replace the incandescent bulb with an LED and resistor, would it make the light brighter? Not sure what it will take to produce a brighter set of headlights - thru that piece of plastic.
Thx,
Mark
Most LEDs would be brighter. If the light bulbs are 12V, then you need a 1K resistor with the LED, and it will be quite bright, even through the plastic.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Just an idea kinda in the 'try the easy stuff first' category - most decoders have a CV that controls how bright the lights are. Any chance for some reason the factory setting for that CV is kinda low on these decoders?
I am not sure which Atlas decoder you have, (the decoders have a # on them) but you did say two function. I have #340 and #341 as a two function and #342 as a four funtion in some of my Atlas HO. My index card on Atlas PC loco. #2753 Alco U23B and other Atlas locos. show they have Atlas decoder's #341. say F4 dims both lights.
My paper work (Atlas, dates back to 1/11/2001).
This may help you, from the Atlas User Manual, decoder item #340. PAGE 7, CV-52 Dimming CV- containes the value used for dimming. 0-255. 0 is dark 255 is max brightness. Factory/default setting is 64. My setting is at 125.
On my instruction sheet I have cv52 highlighted in orange and right below it I have cv53 ''X'' out and I have the black line between cv52 and cv53 on the instruction sheet whited out and a #53 penciled in again. It is possible the Atlas printed sheet was wrong and instead of cv52 I used cv53. It was a long time ago. Saying all that, I would bet on cv52 being the correct number to use.
Most of my Atlas 38's and 40's have been upgraded from Atlas DCC boards to WoW Sound in the past two or three years.
iawestern I have an HO scale Atlas Master series GP-38 loco, which comes with their basic 2 function decoder. The headlight is quite dim for my taste. I have tried moving the bulb closer to the piece of plastic that is supposed to 'carry the light' to the headlights and number boards. Didn't make much difference. Would like to keep using the decoder as long as it works. The info sheet in the box from Atlas indicates that the two function outputs have a current rating of 200mA. What are my options? If I replace the incandescent bulb with an LED and resistor, would it make the light brighter? Not sure what it will take to produce a brighter set of headlights - thru that piece of plastic. Thx, Mark
Yes. I have several of those older Atlas GP38's. Wonderful locos BTW. But the old school bulbs are not bright. LED with a 1K ohm resistor to each LED is a good choice. I'd think that running the incandescent bulb and full voltage might shorten its life.
Even if you went through the tedious work of modifying the light pipes, adding the LEDs is easier work and less invasive to the loco, and brighter, IMO.
Avoid getting LEDs with a blueish hues, cool white. Sometimes Yellow is too yellow. Warm white is my favorite, but some may think its too white.
- Douglas
Doughless Avoid getting LEDs with a blueish hues, cool white. Sometimes Yellow is too yellow. Warm white is my favorite, but some may think its too white.
Rich
Alton Junction
I learned the hard way in my early decoder installs (this was before "white" LEDs were even available) that too much heat from the stock incandescent lamp can result in unfortunate circumstances:
LL_Berk-melt by Edmund, on Flickr
From then on it was LEDs all the way!
Good Luck, Ed
Hi Ed,
Nice to know that I am in good company. I once inadvertently replaced a 1.5v incandescent bulb with a 12v incandescent bulb.
Here is a photo of the repaired loco with credit to doctorwayne who provided me with the correct font decals.