Updated 05.01.2014
This small steam engine is a very nice model, compact, heavy and rather detailed. I have three of these locomotives, 80 007 from 2866, 33042 MM2000 and 33043 80 030 museum locomotive. 33042 was equipped with a Delta decoder.
The prototype was made in Germany, in 1928-1929. 39 of these nice locomotives were made. They were in traffic until 1965. 420 kW, 54,4 metric tons, 9.670 mm long.
Preparation for conversion:
Remove the Delta decoder and the motor. I left the wire from
the pick-up shoe, and soldered it to the decoder later on.
Motor:
Installation of the motor itself is very simple. After removing the old motor and
the reversing unit, make sure that all mechanical functions, like the
transmission, wheel axles and the rods, are good and that the locomotive is
clean. Install the new motor parts. Before inserting the brushes,
make sure once more that everything rotates perfect. If required, oil the
rotating parts very carefully. Do not use too much oil, as this may harm
the operation of the locomotive.
Decoder:
The 6090 decoder is popped into a black plastic holder, Märklin part no.
240130. This was used to hold the electronic reversing reversing
unit or decoder in the early models of these locomotives, like the 3304, 3504
and 3604.
Note that the metal "tub" has a front wall. The front wall of
the plastic holder must be cut off.
Decoder adjustment:
Max. speed:
The Br 80 had a maximum speed of 45 km/h. The speed
potentiometer must be set to minimum.
Acceleration and braking delay:
The potentiometer is adjusted to maximum.
Front and rear light:
The light printed circuit fitted to this locomotive, Märklin spare part number
240120, may be used almost as it is.
The above photo shows the light circuit board installed in the locomotive.
The only modification done to the board is that the lead between the two bulbs
are cut, just behind the front bulb.
Photo from 2866
The black wire in the photo is orange in 33042, regulated plus from the decoder. The
6090 decoder does not have the orange common plus wire, so I made one by myself.
The reason for this is to have flicker free lamps. If the bulbs are
connected to the locomotive chassis, they flicker according to the digital
signal on the track.
See explanation below, from another conversion.
The screw is insulated from the board with a thin plastic washer or sheet. Check with
a circuit tester before soldering the three wires to the board, just behind the front bulb.
Flicker free light in digital operation:
The 6090 decoder offers no regulated plus for the lights. If the lamps are
connected directly to the locomotive chassis, they will flicker according to the
electrical pulses on the tracks. One way to avoid this is to insulate the
lamp from the locomotive chassis and to make a regulated plus by ourselves.
Solder the cathode (negative) side of a 2,7 Volt Zener diode to the cathode side
of the rectifier diodes of the decoder (see orange arrow). Our regulated
plus is now on the anode end of the Zener diode (purple arrow). The
switchable negative current to the lamps are at the yellow (rear light) and gray
(front light) arrows.
Be very careful, to avoid any short circuits.
Parts used for the conversion:
Märklin no.
Pcs.
Description
6090
1
Conversion set with c90 decoder
240130
1
Decoder holder, as in 3304
240120
1
Light circuit board, as in 3304
610080
2
Bulbs, front lights
-
1
2,7 Volt Zener diode to make regulated plus
-
1
Plastic sheet to insulate light circuit board