B737-200 CREW LOST VISUAL CONTACT WITH TFC THEY WERE SUPPOSED TO FOLLOW AT NIGHT AT DFW.

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ON A VISUAL APCH TO DAL RWY 13R; WE ACCEPTED CLRNC TO FOLLOW ANOTHER ACFT (I BELIEVE A GULFSTREAM). WE HAD HIM AND FIELD IN SIGHT. THE CAPT WAS PF AND HE JOINED ME ON THE ILS FREQ. SHORTLY AFTER WE LOST SIGHT OF THE GULFSTREAM IN THE CITY LIGHTS OF DALLAS. WHILE TRYING TO RELOCATE HIM AND TELL AIR TFC CTL; WE SAW OUR LOC NEEDLES LOOKING LIKE WE HAD GONE THROUGH FINAL AND STARTED A L TURN. AFTER TELLING ATC; THEY GAVE US A R TURN AND POINTED OUT THE TFC AND TOLD US NOT TO DSND ANYMORE. WE RELOCATED THE TFC AND FOLLOWED HIM IN FOR A NORMAL LNDG. AFTER LOOKING AT THE CHAIN OF EVENTS; I THINK IN THE -300; -500; OR -700; WE WOULD NOT HAVE LOST POSITIONAL AWARENESS. BUT IN THE -200; I WAS THE PNF AND I HAD THE ILS FREQ IN TO GIVE THE CAPT DME AWARENESS TO THE FIELD WHILE HE WAS NAVING OFF OF CVE (COWBOY VOR). ONCE WE ACCEPTED THE VISUAL APCH; THE CAPT WENT TO THE ILS FREQ ALSO AND IN RETROSPECT; I THINK I SHOULD HAVE TUNED UP CVE FOR BETTER POSITIONAL AWARENESS UNTIL WE WERE ESTABLISHED ON FINAL. IN WHICH IF WE WERE IN THE OTHER ACFT; THAT WOULD HAVE BEEN THE CASE. SUPPLEMENTAL INFO FROM ACN 527732: ONCE WE WERE BACK ON BASE WE REACQUIRED BOTH THE FIELD AND THE ACFT. SUBSEQUENT APCH AND LNDG WERE UNEVENTFUL. ONE PLT (PNF) LEAVING A NEARBY VOR ON FOR POS REF COULD HAVE PRECLUDED THIS. I ALSO BELIEVE THAT THERE NEEDS TO BE AN NDB ON BOTH SIDES OF THE FIELD IF THERE IS NO VOR ON THE FIELD.