DIGITAL MODULATOR CIRCUIT

[TDE]

I need a circuit that I can take an 8 bit digital data signal and modulate it
onto a standard telephone line, and if possible a second circuit to demodulate the signal to recover the 8bit data, I would like these circuits
to be easy to construct

 

[kinjalgp]

For 8-bits or more you'll require a complete MODEM on both ends of the telephone line. No other smaller alternative.
If you want only 10-12 numbers to be transmitted/received, you can use UM91214 DTMF generator and KT3170 DTMF decoder ICs.
Remmber, hooking up anything to your telephone line without permission of telephone company is illegal.

 

[bogdanfirst]

why dont you try to use a parallel to serial converter and then on the other end a serial to parallel converte?

 

[kinjalgp]

Without modulation data can not be transmitted over telephone line. Even if you Serial to parallel and parallel to serial converters, MOD/DE-MOD will be required.