Model Railroading > Kato HO SD40-2 Snoot DCC question

Hello,

I installed a beacon on a Kato SD40-2 Santa Fe snoot and am having brain freeze on where to land the common lead from the bulb onto the Kato board. Anyone know? Thanks for any help.


Dave Dane

The Kato board is for a forward and rear head light only. There is no option for adding a beacon. You can wire an led in parallel to the front headlight and it will be continuously on with the front headlight. If you buy an led with a built in flasher that may look better.

There are circuits which will flash an led or light bulb. These cost nearly as much as a DCC decoder, though.

Posted from Windows Phone OS 7

Thanks for the reply...............I neglected to tell you I have a digitrax decoder installed. .I just was hoping I could land the common lead on the Kato board common.

Dave Dane

Dave,

I have not seen a Kato DCC ready light board so I can't really say but my guess there may be something on the board for F5 and F6. Baring that you can cut the green wire on the way to the light board from the decoder. Then wire in a resistor on the way to the light bulb. Under the decoder shrink wrap at the rear there are 3 solder points for F5, blue common and F6. You can use the blue for common and F5 for the beacon if you like. This is on the 165 decoder and I think the 163 as well.

Let us know how it goes.

Posted from Windows Phone OS 7

fbe.............thanks for the suggestion I will just peel back decoder wrapper and use the common pad. Thanks for the reply.


regards,Dave Dane

The common for the headlights is the common for the accessory F4 & F5 tabs as well.
So headlight, taillight, and beacon all use the same common blue wire.
Most instruction sheets say to place the resistor on the white, yellow, green or brown wires if using LEDs unless the decoder comes "LED compatible".
chers
Dave

If the unit is DCC ready there may be no wires visible or just the wires from the decoder to the 8 pin or 9 pin connection on the board. While it would be possible to use a multimeter to determine the positive side of the headlight leds these are part of the light board soldered in tightly with no blue wire connection. It will probably be easier just to use the F5 and blue wire common points under the shrink wrap of the decoder to hook up the beacon. This requires the proper resistor in the F5 line to the bulb though the same resistor value in the blue wire common works just as well.

If you are trying to use the + side of the headlight led it is only a 3 volt circuit. I am not sure how that works with the green F5 function which is 14 v if both decoder points are used.

Posted from Windows Phone OS 7