NAV ERROR ELECTRONIC INTERFERENCE.

Narrative

ON DEP FROM PDX; DUE TO AN ERROR IN OUR MAG HDG INDICATORS; OUR GND TRACK DID NOT CONFORM TO PUBLISHED TRACK AND WHEN GIVEN HDGS BY DEPT CTL; OUR TRACK DID NOT CONFORM TO WHAT THEY EXPECTED. OUR FLT ORIGINATED IN SEA WAS SUPPOSED TO BE DIRECT HNL; BUT DUE TO A MECHANICAL; 60 PLUS PAX IN PDX WOULD BE LEFT BEHIND HENCE WE WERE TO MAKE A STOP AT PDX TO GET THEM. TRIP TO PDX WAS UNEVENTFUL. ONCE AT THE GATE; I SHUT DOWN THE INS; REPWRED AND INSERTED PROPER GATE COORDINATES AND COMPLETED THE REMAINDER OF THE S/O PREFLT. THEN I JOINED THE CAPT/FO TO FAMILIARIZE MYSELF WITH THE FLT PLAN. WE ALL THEN WENT TO THE COCKPIT ABOUT THE SAME TIME. ALMOST IMMEDIATELY GND PERSONNEL ADVISED US THEY WERE READY TO PUSH BACK. WE ADVISED THEM TO WAIT. ALTHOUGH 'THEY' WERE READY TO GO WE HAD TO ASK FOR REQUIRED INFO SUCH AS FUEL DENSITY AND OUR CLOSEOUT MGL; THE LATTER AFTER WE HAD PERFORMED A TIME CONSUMING SEARCH OF COCKPIT PAPERS AND NOT FINDING IT. THE CAPT HAD ALSO BEEN ADVISED OF THE NEED TO HURRY AS THE GATE WAS NEEDED AND THE TOW BAR BELONGED TO ACR X AND WAS NEEDED. THOUGH WE WERE RUSHED BY GND PERSONNEL; WE COMPLETED ALL CHKLIST ITEMS PROPERLY AT WHAT WE THOUGHT WAS OUR PACE. UPON CALLING FOR PUSHBACK WE WERE ADVISED OF A DEP FLOW TIME THAT WAS ABOUT 10 MINS AWAY. START AND TAXI WERE NORMAL. UPON SWITCHING TO TWR WE WERE CLRED ONTO THE RWY (28L) WITH AN ADVISORY THAT A JETSTREAM WAS ON 4 MI FINAL. UPON RECEIVING TKOF CLRNC; WE WERE ADVISED THAT THE JETSTREAM WAS ON 3 MI FINAL. ALL OF THIS CONTRIBUTED TO A HURRY UP ATMOSPHERE RESULTING IN NO CREW MEMBERS BEING ABLE TO SAY WITH 100 PERCENT ASSURANCE THAT THE MAGNETIC HDG WAS 280 DEGS DURING TKOF RUN-UP. IN ANY CASE; WHEN AIRBORNE SOME CONFUSION AROSE AS THE PF TRIED TO USE MAGNETIC HDGS TO FLY A GND TRACK. I NOTED A LARGE SWING (90 DEG) IN MAGNETIC/TIME AS THE PF ALTERNATED BTWN INS/VOR ON THE HDG SELECT. I POINTED THAT OUT TO THE PF AND POINTED OUT THE MAGNETIC COMPASS READING BUT HE WAS CONFUSED AS TO WHAT WAS HAPPENING. TO COMPOUND THE PROB; NEWPORT VOR DIDN'T LOCK ON FOR 3-4 MINS AND WE COULD NOT TRACK TO THAT. FINALLY IT LOCKED ON; WE TURNED TO A MAGNETIC COMPASS HDG TO THE VOR; SLAVED THE RMI'S TO THE MAGNETIC COMPASS AND PROCEEDED WITH THE FLT. ONE FACTOR WHICH CONTRIBUTED TO THE CONFUSION WAS HASTE. WE WERE ON THE GND 61 MINS AND AT THE GATE ONLY 41 MINS. THE GATE AGENT WAS READY! THE GND CREW WAS READY! YET WE HAD TO ASK EACH FOR ITEMS THEY WERE SUPPOSED TO PROVIDE. THEN ATC GAVE US A TKOF WINDOW -- THEN TFC WAS ON '3 MI FINAL' -- I CANNOT SAY FOR SURE IF THE HDG ERROR OCCURRED PRIOR TO OR DURING OR AFTER AIRBORNE. AFTER LNDG AT DEST; A DEAD HDG PLT RELAYED THE FACT THAT A PORTABLE COMPUTER WAS OPERATING DURING TKOF AND CLB!!