Profi 2000

Multiplex Profi 2000
The Profi 2000 is a Module-based transmitter from the early 1980's. I'm sure this is not the oldest of Multiplex radio TX, but its the oldest in my collection.
Description
- 9 channel
- Dip switches were for servo reverse and channel setup.
- The Tx has a plug-in "personality" module. The module in the TX is for Aerobatics. The one adjacent is a Helicopter module.
- The whole program, adjusters, servo reverse etc. were on the module. By changing the module, you would change the type of radio it became. A helicopter radio, aerobatic radio, sport radio or glider radio.
- There was no memory with this setup. You either buy one module per model (expensive), or do as I did, copy on paper the trim position. ( I know I'm cheap!)
- Very good programmable mixing via the trim knobs.

Dip switches and knobs
- The Tx came with a RF plug in module. Frequency spacing was 10kz.
- The probe next to the TX on the photo is an RPM probe which worked with 2-3-4 blades propellers.
- Power was from a 8.75 volts (7 cell) pack.
- It had an onboard fuse. You could set it for Mode 1 or Mode 2 internally, and all the programs would adjust to it.

This back view with thanks to Enrico Pocopagni. Note PPM/PCM switch.