Dekooderit/DELTA-dekooderit
Generally, "DELTA" decoders and "digital" decoders understand all the same Märklin/Motorola signal on the track. This signal may be generated by Central Units, Delta Controls, Intelliboxes, DDL, etc. The terms "DELTA" and "digital" are used only for marketing purposes. "Delta" are the low-end decoders, "digital" are the full-featured decoders. There is no one-and-only DELTA decoder. DELTA decoders have been made in many varieties.
The DELTA decoder 6603 with 701.13 chip
| chip | 701.13 |
| headlight | directional |
| functions | - |
| addresses | 15 digital, configured by solder bridges, automatic analog mode |
| motor | SFCM, LFCM, DCM |
The early DELTA decoder had a 701.13 chip, addresses are configured by solder bridges. The full address range can be used with some additional soldering. The advantage is that this decoder automatically detects the presence of analog track voltage and locos run on analog track. The decoder is suitable for standard Märklin motors, i. e. for the small and large flat collector motors (SFCM, LFCM) and for the drum collector motors (DCM).
- get 15 Delta addresses by Rutger Friberg, on FTP-server Märklin USA
- get all digital addresses by Rutger Friberg, on FTP-server Märklin USA
- Delta decoder schematics and modifications (functions, addresses) by Dr. Michael König
- get aux. function output by Märklin USA
- drive a DC motor by Märklin USA
The DELTA decoder 6603 with 701.17 chip
| chip | 701.17 |
| headlight | directional, always on, brightness depends on speed, flickering |
| functions | - |
| addresses | DIP switch, 15 digital, one for analog mode |
| motor | SFCM, LFCM, DCM; 27 speed steps |
| size | 36 × 21 × 4 mm |
Later types had a 701.17 chip, 15 addresses can be configured by DIP-switches. Although the chip supports remote control of the head lights, this is not used but the headlights are driven by the motor outputs. Therefore headlights are directional, cannot be turned off, and lamp brightness is proportional to motor speed. When the loco stands still, lights go off. One end of the lamp connections is the loco chassis, therefore lights are flickering. To run a loco on analog, the "analog" loco address has to be set. The motor output supports 27 speed steps but they may not be noticed, because the motor output is not a control loop. The motor output drives standard Märklin motors, i. e. SFCM, LFCM, and DCM. The 6603 as a spare decoder disappeared in 2000 but has still been used in factory-equipped locos in later years.
Schematics can be found at the website of Dr. König. Several websites describe DIY modifications on how to get the lights flicker-free, how to get the lights permanently on and remote controllable, how to address any of all 80 digital addresses, how to drive a DC motor, and even how to make the extra functions f1 - f4 available:
- Delta decoder schematics and modifications (functions, addresses) by Dr. Michael König
- Delta decoder with f1 + f2 function output by Bo Brændstrup
- Delta decoder modifications: aux. function, 80 adr. by Kenneth Pallund
- drive a DC motor by Märklin USA
- German "manual" on how to wire the 6603 and other decoders by Ralf Büker
The DELTA decoder 66031
| chip | 701.21 |
| headlight | directional, always on, constant brightness, flicker-free, protected |
| functions | telex, protected |
| addresses | DIP switch, 15 digital, one for analog mode |
| motor | SFCM, LFCM, DCM; 27 speed steps, protected |
| size | 36 × 21 × 4 mm |
The 66031 is a DELTA decoder with a 701.21 chip, introduced in 1997. Headlights are directional, permanently on, independent from speed. Lamps can be wired flicker-free. An extra function is available for telex couplers or other effects, this function is activated by repeated direction reversals of the loco. The motor output supports 27 speed steps. The motor output drives standard Märklin motors, i. e. SFCM, LFCM, and DCM. All outputs (motor, light, and function) are overload and short-circuit protected. Due to limited features of the 701.21 chip no DIY modifications exist to make further features available. Positive and negative rectified track voltage is available for flicker-free lighting and as supply for other circuits, e. g. sound modules. Addresses are set with a DIP switch, providing 15 digital addresses and one analog mode. The full address range can be used with some soldering.
- Schematic and Pictures of the 66031 from myself.
- Delta decoder 80 adresses by Kenneth Pallund
- drive a DC motor by Märklin USA
- German "manual" on how to wire the 66031 and other decoders by Ralf Büker
The DELTA decoder 66032
| chip | 701.43 |
| headlight | directional, always on, constant brightness, flicker-free, protected |
| functions | telex, protected |
| addresses | DIP switch, 80 digital, automatic analog mode |
| motor | SFCM, LFCM, DCM; 27 speed steps, protected |
| size | 36 × 21 × 4 mm |
The 66032 is the current DELTA decoder since 2002. In its factory-delivered form the features are comparable to the 66031: Headlights are directional, permanently on, independent from speed. Lamps can be wired flicker-free. An extra function is available for telex couplers or other effects, this function is activated by repeated direction reversals of the loco. The motor output supports 27 speed steps. The motor output drives standard Märklin motors, i. e. SFCM, LFCM, and DCM. All outputs (motor, light, and function) are overload and short-circuit protected. Positive and negative rectified track voltage is available for flicker-free lighting and as supply for other circuits, e. g. sound modules. Addresses are set with a DIP switch, and this decoder is the first DELTA decoder providing all 80 digital addresses. The decoder automatically detects analog mode.
If you want the headlights not permanently on but remotely controllable via the "function" button of a 6021 or 66045 delta control, the modification is surprisingly simple; and the decoder becomes a true successor also of the 6080. In addition, the output intended for a telex coupler, which is by default controlled by repeated direction reversals, can be converted to be remotely controllable via the "f1" button of a 6021 or equivalent control unit.
- modifications of the 66032
- remotely controllable function (in English and German) by Jürgen Schad
- schematic of the 66032 by Joachim Schröder
Special DELTA decoders
Sometimes non-standard decoders are built into locomotives. Reasons can be space limitations or electrical reasons.
- Steam locos with a 2'2'T26 tender or cabin tender (BR01, BR03, BR41, BR43, BR44, BR50, BR52) have a delta decoder, spare number 664150 or 600258, of special larger size that is customized to fit onto the tender weight and includes a lamp socket for rear light. A digital equivalent is listed further below.
- The model of the E69 ("Pauline"), order number 34475, is very small and has a DC motor, therefore a standard 66031 is unsuitable. The delta decoder inside here has a 701.22 chip, and is in fact a regulated decoder, where the adjustment potis are not soldered on the circuit board, but replaced by fixed resistors.
- A detailed list with descriptions of many special DELTA decoders is at the Special DELTA decoder overview (in German) by Hans-Günter Heiserholt