I have two new Kato, N-scale, SD90's, and want to add decoders. I understand that Digitrax has a new decoder DN144K2 just for this loco, but you have to swap out the yellow LED's for the Kato white ones. Anybody done this yet? How hard was it? Any tips or tricks?
MOPAC 1 The right decoder for the SD80/90 is the DN141K2. I have done the conversion and exchanged the LED's without any problem. Just a matter of desoldering the LED's from the original board (and also the decoder board) and resolder the white LED's to the decoder, after cutting them to the right length. But this requires a fine tipped soldering iron and some skills at soldering. Hope this helps Jean-Louis Simonet Visit traiN'ternet : http://www.trainternet.org/ [ 19 August 2001: Message edited by: JLS ]</p>
I've got the tools, and I know how to solder. From the pictures I've seen, it looks as if the leads for the LED's are pretty long, and so should not be easily burned-up. Did you take any extra precautions against excessice heat transfer to the LED's? From your post, it sounds like the Digitrax board is longer than the Kato unit? Thanks for your help.
MOPAC 1 The Digitrax boards are much longer than the Kato ones, so the LED leads has to be trimmed very short (the same as the Digitrax ones). It is very difficult to add a heat sink when soldering as the leads are very short (especially on the front). The best is to make the solder as fast as possible (pre-tin the LED leads). But I had no problem to do that and the LED didn't suffer from the treatment. It looks like the LED's are much more resistant to heating that one could think. Just one word of caution : The Digtrax PCB is probably more fragile than the LED itself, so the technique here is to operate fast. For desoldering the original LED's on the Digitrax board, I heated both leads at the same time with the iron. This should be done in a second or so and the LED will just drop off the board. Then the white LED's are soldered to the board, one lead at a time. If the LED leads are already tinned, it just a matter of heating each lead, one at a time, for a second or two. You should have no problem, except maintaining the LED at the right place when doing the first solder. Jean-Louis Simonet Visit traiN'ternet : http://www.trainternet.org/ [ 20 August 2001: Message edited by: JLS ]</p>
FYI... the DN148K decoder also fits the Kato SD80/90's... I know this for a fact, as I installed them in my 3 Kato SD80MAC's early this summer before Digitrax announced their new decoder. I have yet to swap the White LED's... The 148's do not have all of the transponding feataures of the 141K2, but I already had them on hand, so the price was right Harold [ 23 August 2001: Message edited by: chessie ]</p>
Ok, here's a question for you: If the Digitrax board is longer, instead of cutting off all the LED legs, can you A) shorten the digitrax board, or B) drill small holes through the traces, so the PC board will help support the LEDs, you're just soldering them closer-in than at the very tip?
The DN148K board is much shorter than the "new" board.... in fact, the DN148K is significantly longer than the original Kato light board, Kato part # 17643. According to what I can see, the white LED's with the long leads appear to have been connected thru holes that were drilled into the original Kato circuit board, then soldered over. Harold
Well, after checking-out the price on the new Digitrax decoder, I decided on another path. I installed a spare DZ121 in just minutes by modifying the original light board. The others will be fitted with the Lenz LE077XF, as these are only $23.00 per instead of $45.00 per for the Digitrax replacement decoder.
If you don't feel like waiting for the new Digitrax decoder, or paying $45.00 each for one, N Scale Supply in Denver (www.nscalesupply.com) has excellent instructions for installing the Lenz LE077XF on the original light board. I used a Digitrax DZ121. Caboose Hobbies, also in Denver has instructions that are similar, but easier. MOPAC 1 [ 02 October 2001: Message edited by: MOPAC 1 ]</p>
Here is the exact link to the directions at N Scale Supply http://nscalesupply.com/decoders/KatoSD8090/KatoSD8090.html main page is www.nscalesupply.com
