Hi.
What is the best way to remove the bulbs in the Athearn RTR F7s, Gp38-2s, and GP40-2s and replace them with LED headlights with a DCC decoder?
Thanks for any help.
Modelling HO Scale with a focus on the West and Midwest USA
I have used double sided tape, RTV glue, and so on, to hold the LEDs in position.
There are several ways to do this. For F units you can get a perforated board - the type used in circuit building from Radio Shack, Part number 276-1396. you can cut a strip wide enough to mount 3mm or surface mount LED's, (Miniatronics 12-625-04) or low wattage light bulbs, such as Miniatronics 18-014-10. The height of the board should be tall enough to align with the headlight holes in the body, but not so tall as to touch the body; carefully measure the clearance. For F7 units remove the plastic lamp housing and brass clip, trim the mounting bracket so the remainder forms an L where the bottom of the L is the part mounted to the frame. attach the board to the side of the bracket that faces forward. mount the LED's/ lamps to the board in alignment with the lamp lenses on the body. For LED's the ANODE is connected to the BLUE wire or LAMP COMMON. The CATHODE is connected to a resistor( I recommend 1000 ohms) and the other end of the resistor is connected to a function wire (white, yellow, green, etc.). The lamps are connected without the resistor - refer to your decoder instruction sheet. I would use a separate function for Dual headlight F7s as the top lamp is normally a signal light (MARS or Gyralite).
Another way to do this which works for narrow hood units like Geeps is to buy brass or styrene tube stock and mount a short piece to the inside of the body behind the lens. Use Walthers GOO or Ambroid Fast-N-All. Use brass for lamps and Plastic for LED's. Remove the entire lamp bracket from the chassis. The rest is as described above.
If you want to match the look of modern Athearn RTRs is to mount 1.5V bulbs in the holes of the Geep and SD units, replacing the lenses. This requires using either current limiting resistors, a voltage regulator, or a current regulator to properly energize them.
Some decoders now support 1.5 volt lamps without the need for custom regulators or current resistors. Manufacturers such as Soundtraxx, TCS, Digitrax and Quantum (QSI) have offerings.
You may be able to acquire an Athearn lamp board for a RTR unit from Athearn and wire the 1.5 volt lamps to it. A good lamp to use in this case is Miniatronics Part number 18-001-10. These are more reliable than the Athearn lamps.
Carl in Florida - - - - - - - - - - We need an HO Amtrak SDP40F and GE U36B oh wait- We GOT THEM!
Isn't it possible to replace the Athearn RTR F7 lenses with a 3mm LED mounted in the place of the lenses, like Mike Polsgrove did to an Atlas/Roco F in MRs DCC Corner a while back?
I recently added a Digitrax DH123 decoder to my Atheran F7. The front plastic lense has a clear plastic sprew out the back. I added a small 14v light bulb attached to the sprew with heat shrink tubing, which keeps light out of the cab.
Jim, Modeling the Kansas City Southern Lines in HO scale.
Below is an example of what I had to do. No headlight or number board light.
A factory equipped loco I had to go by.
What I did.
Some styrene tubing was used with yellow glow 3mm LED''s. I sanded off the flange on the LED so it would fit in the tube. A little black paint.
The LED standing up lights the cab when the loco is stopped. I used some Vero board, copper clad PC board with holes punched in it. The resistors are at the Tsunami board.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.