A B737-300 CREW DECLARED AN EMER AND RETURNED TO LAND AFTER A STRONG ELECTRICAL OR INSULATION BURNING SMELL WAS DETECTED AFTER TKOF.

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JUST HANDED OFF TO DEP AND CLBING THROUGH 12000 FT MSL FO MADE COMMENT 'I SMELL A BURNING ODOR.' CONTINUED THE CLB TO CLRED ALT FL230 AND CONTINUED TO INVESTIGATE ODOR. I HAD AS YET NOT SMELLED ANYTHING. WITHIN A MIN OR SO I STARTED TO SMELL AN ACRID/BURNING ODOR SIMILAR TO ELECTRICAL WIRES OR INSULATION BURNING SMELL. IT BECAME STRONGER AS WE CLBED AND I COMMANDED THE SMOKE/FUMES/ODOR QRC; WE DONNED OXYGEN MASKS AND DECIDED ON AN IMMEDIATE RETURN TO ZZZ WITH ATC. I CALLED CABIN ASKED THEM IF THEY HAD ANY UNUSUAL ODOR/FUMES/SMOKE. THEY CALLED BACK WITHIN A COUPLE OF MINS WITH NOTHING UNUSUAL. I TOLD THEM TO PREPARE CABIN FOR LNDG AND WE WOULD BE ON GND IN ZZZ 10 MINS. DECLARED EMER AND LANDED IN VFR CONDITIONS. AFTER LNDG THE ODOR WAS PRETTY MUCH GONE AND WE ELECTED TO TAXI TO GATE AFTER AGAIN CHKING WITH CABIN CREW. CALLBACK CONVERSATION WITH RPTR ACN 787968 REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT THE SOURCE OF THE ELECTRICAL SMELL WAS THE AUTOPLT MCP ON THE FRONT GLARE SHIELD.