diff --git a/src/main.c b/src/main.c
--- a/src/main.c
+++ b/src/main.c
@@ -61,9 +61,6 @@ int main(void)
     uint8_t nextwspr_time_valid = 0;
     uint32_t last_wspr_tx_time = 0;
 
-    uint8_t fix_ok = 0;
-    uint8_t numsats = 0;
-
     uint8_t packet_type = 0;
 
     while (1)
@@ -158,6 +155,7 @@ int main(void)
                     // TODO: Set wspr countdown timer for this transmission!
                     fix_acq_starttime = 0;
                     state = SYSTEM_WSPRTX;
+                    adc_start();
                 }
                 // If no decent fix in 3 minutes
                 else if(HAL_GetTick() - fix_acq_starttime > 60000 * 3)
@@ -196,12 +194,14 @@ int main(void)
                         packet_type = !packet_type; // alternate packet type
 						last_wspr_tx_time = HAL_GetTick();
 						state = SYSTEM_IDLE;
+                        adc_stop();
             		}
             		else
             		{
             			// Window was missed, go back to idle, and try again after time delay
 						last_wspr_tx_time = HAL_GetTick();
             			state = SYSTEM_IDLE;
+                        adc_stop();
             		}
                     nextwspr_time_valid = 0; // invalidate wspr time
                 }