diff --git a/components/ratgdo/secplus1.cpp b/components/ratgdo/secplus1.cpp
index b175981..cc0b666 100644
--- a/components/ratgdo/secplus1.cpp
+++ b/components/ratgdo/secplus1.cpp
@@ -106,7 +106,7 @@ namespace secplus1 {
         if (action == LockAction::TOGGLE || 
             (action == LockAction::LOCK && this->lock_state == LockState::UNLOCKED) || 
             (action == LockAction::UNLOCK && this->lock_state == LockState::LOCKED)) {
-            this->transmit_packet(toggle_lock);
+            this->transmit_packet(toggle_lock, this->is_0x37_panel_);
         }
     }
 
@@ -236,6 +236,12 @@ namespace secplus1 {
         return Command{cmd_type, packet[1]};
     }
 
+    // unknown meaning of observed command-responses: 
+    // 40 00 and 40 80
+    // 53 01
+    // C0 3F
+    // F8 3F
+    // FE 3F
 
     void Secplus1::handle_command(const Command& cmd)
     {
@@ -268,6 +274,7 @@ namespace secplus1 {
             this->ratgdo_->received(door_state);
         }
         else if (cmd.type == CommandType::DOOR_STATUS_37) {
+            this->is_0x37_panel_ = true;
             // inject door status request
             this->sw_serial_.write(0x38);
         } else if (cmd.type == CommandType::OTHER_STATUS) {
@@ -296,7 +303,7 @@ namespace secplus1 {
         }
     }
 
-    void Secplus1::transmit_packet(const TxPacket& packet)
+    void Secplus1::transmit_packet(const TxPacket& packet, bool first_byte)
     {
         this->print_tx_packet(packet);
 
@@ -310,18 +317,19 @@ namespace secplus1 {
             this->sw_serial_.write(packet[0]);
             this->sw_serial_.enableIntTx(true);
         });
-        this->scheduler_->set_timeout(this->ratgdo_, "", tx_delay+250, [=] {
-            this->sw_serial_.enableIntTx(false);
-            this->sw_serial_.write(packet[1]);
-            this->sw_serial_.enableIntTx(true);
-        });
-        this->scheduler_->set_timeout(this->ratgdo_, "", tx_delay+290, [=] {
-            this->sw_serial_.enableIntTx(false);
-            this->sw_serial_.write(packet[1]);
-            this->sw_serial_.enableIntTx(true);
-        });
-
 
+        if (!first_byte) {
+            this->scheduler_->set_timeout(this->ratgdo_, "", tx_delay+250, [=] {
+                this->sw_serial_.enableIntTx(false);
+                this->sw_serial_.write(packet[1]);
+                this->sw_serial_.enableIntTx(true);
+            });
+            this->scheduler_->set_timeout(this->ratgdo_, "", tx_delay+290, [=] {
+                this->sw_serial_.enableIntTx(false);
+                this->sw_serial_.write(packet[1]);
+                this->sw_serial_.enableIntTx(true);
+            });
+        }
     }
 
 } // namespace secplus1
diff --git a/components/ratgdo/secplus1.h b/components/ratgdo/secplus1.h
index db45796..2070097 100644
--- a/components/ratgdo/secplus1.h
+++ b/components/ratgdo/secplus1.h
@@ -81,7 +81,7 @@ namespace secplus1 {
         void print_tx_packet(const TxPacket& packet) const;
         optional<Command> decode_packet(const RxPacket& packet) const;
 
-        void transmit_packet(const TxPacket& packet);
+        void transmit_packet(const TxPacket& packet, bool first_byte = false);
 
         LightState light_state { LightState::UNKNOWN };
         LockState lock_state { LockState::UNKNOWN };
@@ -92,6 +92,8 @@ namespace secplus1 {
         uint32_t wall_panel_emulation_start_ { 0 };
         WallPanelEmulationState wall_panel_emulation_state_ { WallPanelEmulationState::WAITING };
 
+        bool is_0x37_panel_ { false };
+
         // bool transmit_pending_ { false };
         // uint32_t transmit_pending_start_ { 0 };
         TxPacket tx_packet_;