RPM Measurement (rotary Encoder)

Hi,

I am measuring Dc motor RPM using a rotary encoder(custom made).The input supply to the encoder is 3.3v and the encoder output(Sine wave) is given to the Schmitt trigger to get square shaped signal.
I read this signal through a microcontroller for controlling the motor.

I have few question regarding this.

The length of the wire which I use to transfer the signal from encoder to PCB board(microcontroller) is 5 meter.Is this a problem 3.3v signal travelling for 5mts?
If so, then I have a 5v supply in the board can I use that instead of 3.3v?

If I am using a 5v instead of 3.3v should I have to use levelshifter(Again Microcontroller uses 3.3v control)?What kind of level shifter can I use for this?

Additional information:
Encoder Signal Frequency : 2-5khz

Any idea??:?:

I would use a screened cable for the encoder output. Make sure that the supply feed at the encoder end is decoupled with an extra capacitor from +Vcc to earth. Long wires act like aerials and pick up noise from machines and flourescent lights, best to keep the noise out of your signal wires. At this low frequency there should be no degradation of your actual signal.
Frank