Decoder test

This is a short video clip (below) about how the deocder in Fleischmann's ÖBB 2048 from the start set "behaves" when it meets a DCC signal with low voltage. The voltage meter is an analog meter connected to a bridge rectifier which is connected to the track. So it shows a little less (diode voltage drop) than the real DCC voltage on the track which is an AC rectange wave.

As the critical point is around 9.5V, this is how we start our test. At first, I just let it sit there and wait. In the second try, I try to run it slowly from the controller. It does not take many seconds until the jumping starts and it does not end until the loco is lifted or the electricity is otherwise cut.

As the jumping does not occur when the analog mode is off (adjust CV12 and CV29 for that), I guess that it wrongly tries to interpret the DCC signal as opposing DC voltages. When DC operation is turned off, the loco may start eventually running at some speed but will then continue to run forward without any way to control it. But that is not as fun to film.

According to the NMRA standard, a DCC decoder should continue to work as low as 7V DCC.

Decoder identification


CV8 = 161
CV7 = 121

Clips