diff --git a/src/main.cpp b/src/main.cpp
index 085c067..d456938 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -87,6 +87,8 @@ static float jamFreq2 = JAM_LOCK_FREQ_2_MHZ;
 // Gate LFSR ISR so GDO0 is only toggled for radios in direct async TX (avoids driving idle CC1101).
 static volatile bool s_noiseEn1 = false;
 static volatile bool s_noiseEn2 = false;
+// ISR must not read jamMode (non-atomic); noiseGenStart sets this for PULSE vs PRNG.
+static volatile bool s_noiseIsPulse = false;
 
 // Auto-reinit watchdog
 static uint32_t lastReInitCheck = 0;
@@ -1075,16 +1077,17 @@ static void jamFloodTick() {
       (void)radio2.transmit(pkt, 60);
     }
   } else {
-    // Flood mode: 64-byte payload, 2ms wait, async transmit.
+    // Flood: full transmit() — startTransmit() without finishTransmit() was aborting
+    // each packet on the next tick (standby() at start of TX), so almost no on-air energy.
     if ((uint32_t)(millis() - lastMs) < 2u) return;
 
     if (radio1Status == 2) {
       esp_fill_random(pkt, sizeof(pkt));
-      (void)radio1.startTransmit(pkt, sizeof(pkt));
+      (void)radio1.transmit(pkt, sizeof(pkt));
     }
     if (radio2Status == 2) {
       esp_fill_random(pkt, sizeof(pkt));
-      (void)radio2.startTransmit(pkt, sizeof(pkt));
+      (void)radio2.transmit(pkt, sizeof(pkt));
     }
   }
   
@@ -1557,7 +1560,7 @@ static inline IRAM_ATTR uint32_t lfsrStep(uint32_t s) {
 }
 
 static void IRAM_ATTR noiseISR() {
-  if (jamMode == JamMode::PULSE) {
+  if (s_noiseIsPulse) {
     static uint32_t pulseToggle = 0;
     pulseToggle ^= 1;
     if (s_noiseEn1) gpio_set_level((gpio_num_t)CC1101_1_GDO0, pulseToggle);
@@ -1585,6 +1588,8 @@ static void noiseGenStart() {
   s_lfsr = esp_random();
   if (s_lfsr == 0) s_lfsr = 0xDEADBEEFu; // LFSR must never be zero
 
+  s_noiseIsPulse = (jamMode == JamMode::PULSE);
+
   pinMode(CC1101_1_GDO0, OUTPUT);
   pinMode(CC1101_2_GDO0, OUTPUT);