I have an Athearn HO SD50 that I installed a Digitrax DH123 Decoder in last night. The problem is that it takes almost half the throttle to get it moving.
I have an NCE Powerhouse Pro Radio 5 amp DCC system. The throttle goes from 0 - 126 on the 128 speed step level.
The loco doesn't start moving until the throttle is at 60. Most of my other loco's start moving anywhere from 1 - 15. The Athearn SD50 also is really slow at max speed.
I have a Proto 2000 SD50 that has an NCE Decoder in it and it starts moving around 10.
I checked CV2 and it is at 0. Should I set it at a higher value or should the lower value be correct? Or what can I do to get it moving at a lower speed setting and get better top speed out of it?
Thanks,
Bill
Bill, that sounds like my post I made a few weeks ago, same engine and decoder. Never got it right and melted the decoder. All so blew the head lights fast.
I pulled the burnt decoder and installled the DC chip, still took 60% power to get it to move and blew the lights again? Top speed was a round 40 sMPH a WOT. Later today I am going to strip the engine, check the trucks and re motor it and see what happens. I would run it on DC and see what happens and save the decoder.
Cuda Ken
I hate Rust
Before you start messing with start volts and all that fun stuff, reset the decoder by programming CV8 = 8. Just in case something was left in an odd state from manufacturing or testing. Plus it gives you a definite starting point.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks for the help.
As suggested I'll reset the decoder to factory settings and see if that makes a difference. If not, then I'll change CV2 to a greater value.
Setting the CV value is what is confusing. I thought at "0" it would start at a minimum voltage. Guess I was wrong. The other problem is the Digitrax paperwork doesn't go through the CV values so it leaves you to guess what's right.
I'll make the changes when I get home tonight.
The CV2 value isn't the speed step you want it to start at, either, it's usually a percentage of full track voltage, either 0-99 or 0-255 - if 0-255, 128 would be 50%. Best way to set it is if your system allows programming on the main. Select the loco and set the throttle to speed step 1, then go into the programming mode and plug values into CV2 until it starts to just barely creep. You might want to back that resulting value down 1 or 2 so that it takes speed step 2 to actually start creeping if you have grades - otherwise step 1 cold be too sudden a movement when going downhill.
I appreciat all the help. Last night I got a chance to work on the loco. First I tried resetting the decoder to factory settings changing CV#8 to a value of 8. Then I had to program the long address again. Then I tried it on the main and there was no change.
Then I programmed on the main and changed the start voltage CV#2 to a value of 50. That still was not enough to get it moving at speed step 1. I kept increasing the value until it finally started creaping at a value of 63. Then I set the max speed, CV#6 to a value of 255 and then found the mid level value and set CV#5 to 159.
Once all that was done I tested it out. It ran fine starting off but still seemed auwful slow at top end. I have a second Athearn SD 50 that was purchased at the same time that also needed a decoder so I installed my last Digitrax DH123 in it and followed the same procedures as above.
It had a lower starting value so that changed the mid value but I kept the max speed at 255. I then tested it out and it ran much faster at top speed.
I then put both loco's on the layout and ran them at the same speed steps but the second loco was faster. It would pull away by several feet while going up hill so I tried speeding it up to keep up with the other loco.
While this was going on I also tried the top speed which had the same effect at first but after approximately 10 - 15 minutes the slower loco started catching the lead loco.
After fooling around for about half an hour both loco's seemed to operate very closly to the same speed steps. I have a little fine tuning still but they work much better than before.
Again thanks to everyone for their help