diff --git a/stixcore/calibration/transmission.py b/stixcore/calibration/transmission.py
index 89bb2dc1..e1c31509 100644
--- a/stixcore/calibration/transmission.py
+++ b/stixcore/calibration/transmission.py
@@ -180,7 +180,7 @@ def generate_transmission_tables():
     datetime.now().strftime('%Y%m%d')
     trans = Transmission()
 
-    energies = np.linspace(2, 150, 1001) * u.keV
+    energies = np.append(np.arange(2, 20, 0.01), np.arange(20, 160, 0.1)) * u.keV
 
     norm_sci_energies = trans.get_transmission()
     norm_sci_energies.write(f'stix_transmission_sci_energies_{cur_date}.csv')