diff --git a/ohmpi/hardware_system.py b/ohmpi/hardware_system.py
index 4ef57096213f9f1b14184665ae20451dd0159fa6..a4d1a9e6836f00d973ff4de8858f3fa05892de12 100644
--- a/ohmpi/hardware_system.py
+++ b/ohmpi/hardware_system.py
@@ -623,6 +623,9 @@ class OhmPiHardware:
                 self.tx.voltage = vab
         else:
             vab = self.tx.voltage
+        if self.tx.pwr.pwr_state == 'off':
+            self.tx.pwr.pwr_state = 'on'
+            switch_pwr_off = True
         # reads current and voltage during the pulse
         injection = Thread(target=self._inject, kwargs={'injection_duration': duration, 'polarity': polarity})
         readings = Thread(target=self._read_values, kwargs={'sampling_rate': sampling_rate, 'append': append})
@@ -631,7 +634,8 @@ class OhmPiHardware:
         readings.join()
         injection.join()
         self.tx.polarity = 0   #TODO: is this necessary?
-
+        if switch_pwr_off:
+            self.tx.pwr.pwr_state = 'off'
     def _vab_pulses(self, vab, durations, sampling_rate, polarities=None, append=False):
         switch_pwr_off, switch_tx_pwr_off = False, False
         if self.pwr_state == 'off':
diff --git a/ohmpi/ohmpi.py b/ohmpi/ohmpi.py
index 78df6fe1f46e7b937c5bbda36af5f7fd194eba11..f5295447e3c453f849f49a2fe0740d88c5ea25d7 100644
--- a/ohmpi/ohmpi.py
+++ b/ohmpi/ohmpi.py
@@ -821,9 +821,7 @@ class OhmPi(object):
         for i in range(0, quads.shape[0]):
             quad = quads[i, :]  # quadrupole
             self._hw.switch_mux(electrodes=list(quads[i, :2]), roles=['A', 'B'], state='on')
-            print('tx', self._hw.tx.voltage)
             self._hw._vab_pulse(duration=0.2, vab=tx_volt)
-            print('tx', self._hw.tx.voltage)
             current = self._hw.readings[-1, 3]
             # if self._hw.tx.pwr.voltage_adjustable:
             #     print('tx',self._hw.tx.voltage)