diff --git a/demod_2400.c b/demod_2400.c
index ffd7ed9..8f5ace7 100644
--- a/demod_2400.c
+++ b/demod_2400.c
@@ -52,72 +52,6 @@ static inline int slice_phase4(uint16_t *m) {
     return m[0] + 5 * m[1] - 5 * m[2] - m[3];
 }
 
-static inline int correlate_phase0(uint16_t *m) {
-    return slice_phase0(m) * 26;
-}
-static inline int correlate_phase1(uint16_t *m) {
-    return slice_phase1(m) * 38;
-}
-static inline int correlate_phase2(uint16_t *m) {
-    return slice_phase2(m) * 38;
-}
-static inline int correlate_phase3(uint16_t *m) {
-    return slice_phase3(m) * 26;
-}
-static inline int correlate_phase4(uint16_t *m) {
-    return slice_phase4(m) * 19;
-}
-
-//
-// These functions work out the correlation quality for the 10 symbols (5 bits) starting at m[0] + given phase offset.
-// This is used to find the right phase offset to use for decoding.
-//
-
-static inline int correlate_check_0(uint16_t *m) {
-    return
-        abs(correlate_phase0(&m[0])) +
-        abs(correlate_phase2(&m[2])) +
-        abs(correlate_phase4(&m[4])) +
-        abs(correlate_phase1(&m[7])) +
-        abs(correlate_phase3(&m[9]));
-}
-
-static inline int correlate_check_1(uint16_t *m) {
-    return
-        abs(correlate_phase1(&m[0])) +
-        abs(correlate_phase3(&m[2])) +
-        abs(correlate_phase0(&m[5])) +
-        abs(correlate_phase2(&m[7])) +
-        abs(correlate_phase4(&m[9]));
-}
-
-static inline int correlate_check_2(uint16_t *m) {
-    return
-        abs(correlate_phase2(&m[0])) +
-        abs(correlate_phase4(&m[2])) +
-        abs(correlate_phase1(&m[5])) +
-        abs(correlate_phase3(&m[7])) +
-        abs(correlate_phase0(&m[10]));
-}
-
-static inline int correlate_check_3(uint16_t *m) {
-    return
-        abs(correlate_phase3(&m[0])) +
-        abs(correlate_phase0(&m[3])) +
-        abs(correlate_phase2(&m[5])) +
-        abs(correlate_phase4(&m[7])) +
-        abs(correlate_phase1(&m[10]));
-}
-
-static inline int correlate_check_4(uint16_t *m) {
-    return
-        abs(correlate_phase4(&m[0])) +
-        abs(correlate_phase1(&m[3])) +
-        abs(correlate_phase3(&m[5])) +
-        abs(correlate_phase0(&m[8])) +
-        abs(correlate_phase2(&m[10]));
-}
-
 //
 // Given 'mlen' magnitude samples in 'm', sampled at 2.4MHz,
 // try to demodulate some Mode S messages.