diff --git a/horusdemodlib/__init__.py b/horusdemodlib/__init__.py
index 970659c..86205cb 100755
--- a/horusdemodlib/__init__.py
+++ b/horusdemodlib/__init__.py
@@ -1 +1 @@
-__version__ = "0.1.16"
+__version__ = "0.1.17"
diff --git a/horusdemodlib/demod.py b/horusdemodlib/demod.py
index 3a5b2cf..5e9ac22 100644
--- a/horusdemodlib/demod.py
+++ b/horusdemodlib/demod.py
@@ -333,6 +333,11 @@ class HorusLib():
         )
         return frame
     
+    def set_estimator_limits(self, lower: float, upper: float):
+        """ Update the modems internal frequency estimator limits """
+        self.c_lib.horus_set_freq_est_limits(self.hstates, c_float(lower), c_float(upper))
+
+
     def add_samples(self, samples: bytes):
         """ Add samples to a input buffer, to pass on to demodulate when we have nin samples """
 
@@ -363,9 +368,10 @@ class HorusLib():
 
 if __name__ == "__main__":
     import sys
-    if len(sys.argv) != 3:
-        raise ArgumentError("Usage python3 -m horusdemodlib.demod mode filename")
+    if len(sys.argv) != 4:
+        raise ArgumentError("Usage python3 -m horusdemodlib.demod mode filename sample_rate")
     filename = sys.argv[2]
+    rate = int(sys.argv[3])
 
     if sys.argv[1] == 'rtty7n2':
         mode = Mode.RTTY_7N2
@@ -394,7 +400,8 @@ if __name__ == "__main__":
         format="%(asctime)s %(levelname)s: %(message)s", level=logging.DEBUG
     )
 
-    with HorusLib(mode=mode, verbose=False, callback=frame_callback, sample_rate=48000, rate=300) as horus:
+    with HorusLib(mode=mode, verbose=False, callback=frame_callback, sample_rate=rate, rate=100) as horus:
+        #horus.set_estimator_limits(10.0, 3000.0)
         with open(filename, "rb") as f:
             while True:
                 # Fixed read size - 2000 samples
diff --git a/pyproject.toml b/pyproject.toml
index d7cfe18..295fe19 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "horusdemodlib"
-version = "0.1.16"
+version = "0.1.17"
 description = "Project Horus HAB Telemetry Demodulators"
 authors = ["Mark Jessop"]
 license = "LGPL-2.1-or-later"
diff --git a/src/fsk.c b/src/fsk.c
index 41248fc..de5cf44 100644
--- a/src/fsk.c
+++ b/src/fsk.c
@@ -628,11 +628,12 @@ void fsk_demod_core(struct FSK *fsk, uint8_t rx_bits[], float rx_sd[], COMP fsk_
     modem_probe_samp_f("t_f_est",fsk->f_est,M);
     #endif
     float *f_est;
-    if (fsk->freq_est_type)
+
+    if (fsk->freq_est_type){
         f_est = fsk->f2_est;
-    else
+    }else{
         f_est = fsk->f_est;
-      
+    }
     /* update filter (integrator) memory by shifting in nin samples */
     for(m=0; m<M; m++) {
         for(i=0,j=Nmem-nold; i<nold; i++,j++)
@@ -1003,6 +1004,7 @@ void fsk_get_demod_stats(struct FSK *fsk, struct MODEM_STATS *stats){
     stats->neyetr = fsk->stats->neyetr;
     memcpy(stats->rx_eye, fsk->stats->rx_eye, sizeof(stats->rx_eye));
     memcpy(stats->f_est, fsk->stats->f_est, fsk->mode*sizeof(float));
+
         
     /* these fields not used for FSK so set to something sensible */
 
diff --git a/src/horus_api.c b/src/horus_api.c
index e28dfdc..2689f37 100644
--- a/src/horus_api.c
+++ b/src/horus_api.c
@@ -921,7 +921,12 @@ void horus_get_modem_extended_stats (struct horus *hstates, struct MODEM_STATS *
 
     assert(hstates->mFSK <= MODEM_STATS_MAX_F_EST);
     for (i=0; i<hstates->mFSK; i++) {
-        stats->f_est[i] = hstates->fsk->f_est[i];
+        // Grab the appropriate frequency estimator data.
+        if (hstates->fsk->freq_est_type){
+            stats->f_est[i] = hstates->fsk->f2_est[i];
+        } else {
+            stats->f_est[i] = hstates->fsk->f_est[i];
+        }
     }
 }