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Marklin 37994

37994 - Steam locomotive with a tender

Union Pacific Railroad (UP) class 4000 “Big Boy” heavy freight locomotive. Version with the road number 4019 as equipped with smoke deflectors. In the winter of 1944/45 this unit had smoke deflectors installed on it as an experiment.

Length 465mm

Road Number


Spare Parts

Contact shoe - E138079

Rubber tyres (4) - 7153

High efficiency motor -

Light bulb -

Smoke generator - 7226 x 2


Marklin “New Items” brochure 2012

Digital Conversion

High efficiency motor -

Decoder - ESU Loksound 5

Decoder CV Values

Set by us.

CV 150Address
CV 17223Long Address 1
CV 1858Long Address 2
CV 2954Configuration Register128 speed steps, enable analogue, Speed curve CV 67 - 94, Long Address
CV 501Analogue modeAC analogue enabled
CV 113255Power Fail Bypass
CV 263128Special function CV1 Front LightSet for LED
CV 271128Special function CV1 Rear LightSet for LED
CV 2751Mode Select Aux 1Set for Relay for smoke generator
CV 27831Brightness Aux 1Set for Relay

ESU Lokpilot recommendations

CV 23Start Voltage
CV 920Motor PWM Frequency (x1000Hz)
CV 5120«K Slow» Cutoff
CV 5220BEMF «K Slow»
CV 53110Control Reference Voltage
CV 5425Load Control Parameter «K»
CV 55200Load Control Parameter «I»
CV 56255BEMF Influence at VMin
CV 116100Slow speed BEMF Sampling periodx0.1 millisecond
CV 117150Full speed BEMF Sampling periodx0.1 millisecond
CV 11820Slow speed BEMF Measurement gap length VMinx0.1 millisecond
CV 11925Full speed BEMF Measurement gap length Vmaxx0.1 millisecond

Serial Number

DCC-EX Roster

ROSTER(7994 , “Marklin 37994”, “Light/Smoke/Cab Light/Shunting/Momentum/ / / /Sound/ / /”)

marklin_37994.txt · Last modified: 2024/03/13 11:23 by rosscoetrain