diff --git a/simulations/airshower_beacon_simulation/aa_generate_beacon.py b/simulations/airshower_beacon_simulation/aa_generate_beacon.py
index 0366b9e..3d86c52 100755
--- a/simulations/airshower_beacon_simulation/aa_generate_beacon.py
+++ b/simulations/airshower_beacon_simulation/aa_generate_beacon.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# vim: fdm=indent ts=4
+# vim: fdm=marker ts=4
 
 """
 Add a beacon measurement on top of the
@@ -15,23 +15,27 @@ from copy import deepcopy
 from earsim import REvent, Antenna, block_filter
 import lib
 
+# {{{ vim marker
 tx_fname = 'tx.json'
 antennas_fname = 'antennas.hdf5'
 
-def write_tx_file(fname, tx, f_beacon):
+def write_tx_file(fname, tx, f_beacon, **kwargs):
     with open(fname, 'w') as fp:
         return json.dump(
-                dict(
-                    f_beacon=f_beacon,
-                    tx=dict(
-                        x=tx.x,
-                        y=tx.y,
-                        z=tx.z,
-                        name=tx.name
+                {
+                    **kwargs,
+                    **dict(
+                        f_beacon=f_beacon,
+                        tx=dict(
+                            x=tx.x,
+                            y=tx.y,
+                            z=tx.z,
+                            name=tx.name
                         )
-                    ),
+                    )
+                },
                 fp
-                )
+               )
 
 def read_tx_file(fname):
     with open(fname, 'r') as fp:
@@ -40,7 +44,10 @@ def read_tx_file(fname):
     f_beacon = data['f_beacon']
     tx = Antenna(**data['tx'])
 
-    return tx, f_beacon
+    del data['f_beacon']
+    del data['tx']
+
+    return tx, f_beacon, data
 
 def read_beacon_hdf5(fname, **h5ant_kwargs):
     with h5py.File(fname, 'r') as h5:
@@ -227,15 +234,26 @@ def write_baseline_time_diffs_hdf5(fname, baselines, true_phase_diffs, k_periods
         data = np.vstack( (time_diffs, f_beacon, true_phase_diffs, k_periods) ).T
         dset = group.create_dataset(dset_name, data=data)
 
+# }}} vim marker
 
 if __name__ == "__main__":
     from os import path
 
+    fname = "ZH_airshower/mysim.sry"
+
+    # Transmitter
     remake_tx = True
 
-    fname = "ZH_airshower/mysim.sry"
-    tx = Antenna(x=-500,y=0,z=0,name='tx') # m
-    if not True: # slowest beacon to be found:
+    tx = Antenna(x=-2e3,y=0,z=0,name='tx') # m
+    if False:
+        # Move tx out a long way
+        tx.x, tx.y = -75e3, 75e3 # m
+    elif False:
+        # Move it to 0,0,0 (among the antennas)
+        tx.x, tx.y = 0, 0 #m
+
+    # Beacon properties
+    if False: # slowest beacon to be found:
         f_beacon =  10e-3 # GHz
         low_bp = 5e-3 # GHz
         high_bp = 80e-3 # GHz
@@ -246,31 +264,35 @@ if __name__ == "__main__":
         low_bp = 30e-3 # GHz
         high_bp = 80e-3 # GHz
 
-    # Disable block_filter
-    if False:
-        block_filter = lambda x, dt, low, high: x
-
-    beacon_amplitudes = 1e-6*np.array([1e2, 0, 0]) # mu V/m
-    beacon_radiate_rsq = True
+    beacon_amplitudes = 1e-6*np.array([1e5, 0, 0]) # mu V/m
+    beacon_radiate_rsq = True # beacon_amplitude is repaired for distance to 0,0,0
 
+    # modify beacon power to be beacon_amplitude at 0,0,0
     if beacon_radiate_rsq:
-        # Move tx out, and magnify beacon_amplitude (at tx)
-        tx = Antenna(x=-20e3,y=0,z=0,name='tx') # m
         dist = lib.distance(tx, Antenna(x=0, y=0, z=0))
 
         ampl = max(1, dist**2)
 
         beacon_amplitudes *= ampl
 
+    # Disable block_filter
+    if False:
+        block_filter = lambda x, dt, low, high: x
+
     ####
     fname_dir = path.dirname(fname)
     tx_fname = path.join(fname_dir, tx_fname)
     antennas_fname = path.join(fname_dir, antennas_fname)
 
+    # read/write tx properties
     if not path.isfile(tx_fname) or remake_tx:
-        write_tx_file(tx_fname, tx, f_beacon)
+        write_tx_file(tx_fname, tx, f_beacon, amplitudes=beacon_amplitudes.tolist(), radiate_rsq=beacon_radiate_rsq)
     else:
-        tx, f_beacon = read_tx_file(tx_fname)
+        tx, f_beacon, _ = read_tx_file(tx_fname)
+
+
+    print("Beacon amplitude at (0,0,0) [muV/m]:", beacon_amplitudes)
+    print("Tx location:", [tx.x, tx.y, tx.z])
 
     # read in antennas
     ev = REvent(fname)