Quote from: r0bert on October 02, 2007, 05:41:13 PM
which DCC system are you using, with the digitrax system for example, you need to do a status edit for 28 step operation when calling up the address.

Our club uses a NCE system.  This is the only engine with an issue being jerky out of over 50.  All the other Spectrums are fine, however, none have a Bachmann decoder.  I intend to plug in a digitrax and a soundtraxx decoder and try it.  Others have suggested it may be bad gears.  If the other decoders do not solve it, it will go back to Bachmann and I guess I will wait the 6 weeks for a new model.

Quote from: Jim Banner on October 01, 2007, 11:30:30 PM
Firstly, I assume you tried cleaning the wheels and the rails.  This is the most common cause of poor low speed operation on dc or DCC.

Secondly, was the DCC decoder factory installed or was it installed by the eBay seller?  Open up the tender and see what brand of decoder is inside.  If not a Bachmann decoder, then check to see if the installer removed the capacitors on the adapter board,  shown in this photo:

 

The capacitor(s) look like the yellow blob just above where it says C1.  There may be one or two and they may be blue instead of yellow.  If the capacitor(s) are there and the decoder is not Bachmann, then clip one lead of each capacitor to solve the problem.  Just be sure to leave the other components alone!

Thanks, Jim.  It is a Bachman Decoder and was in the original shrink wrap.  All wheels are clean and it runs like a champ at higher speeds.  The jerky movement is consistant anywhere on the layout.  I have turned the analog off in the decoder.  I guess I will open the tender and switch out the decoder.  Just do not want to go through the hassle with Bachmann.  Took 6 weeks for them to replace a new 0-6-0 which froze the first few feet of run.

Quote from: Atlantic Central on October 01, 2007, 09:48:08 AM
Are you running it on DCC or DC?

Many dual mode decoders are a little baulky at slow speeds on DC. Bachmann included jumpers with your loco so you can remove the decoder for DC use.

Sheldon

Thanks, It is operating on DCC and the analog function turned off.

Quote from: morrisf on October 01, 2007, 10:10:32 AM
Check that the plugs between engine and tender are pushed in all the way.

Morris

Checked and no help.  Thanks

I just purchased, off the internet, a new Spectrum 2-8-0 DCC equipped.  It runs with jerks at slow and start speeds.  Nothing noticable at higher speeds.  I have broken it in, both in reverse and forward for 1/2 hr each at high speed.  No change to jerky operation.

Could this be the decoder or as proposed by a club member, the rods are not in perfect alignment or a broken gear?    I visually see no issue with the rods.  I know it is covered by warranty, but if I can solve here I will save the $10 shipping.  Anyone else experience this problem?  Thoughts welcome.