Convert some telecomms constants into defines

code/game/objects/items/devices/PDA/cart.dm

@@ -256,7 +256,7 @@ var/list/civilian_cartridges = list(
 
 	var/datum/signal/status_signal = new
 	status_signal.source = src
-	status_signal.transmission_method = 1
+	status_signal.transmission_method = TRANSMISSION_RADIO
 	status_signal.data["command"] = command
 
 	switch(command)

code/game/objects/items/devices/PDA/radio.dm

@@ -22,7 +22,7 @@
 
 		var/datum/signal/signal = new()
 		signal.source = src
-		signal.transmission_method = 1
+		signal.transmission_method = TRANSMISSION_RADIO
 		signal.data[key] = value
 		if(key2)
 			signal.data[key2] = value2

code/game/objects/items/devices/communicator/cartridge.dm

@@ -329,7 +329,7 @@
 
 	var/datum/signal/status_signal = new
 	status_signal.source = src
-	status_signal.transmission_method = 1
+	status_signal.transmission_method = TRANSMISSION_RADIO
 	status_signal.data["command"] = command
 
 	switch(command)

code/game/objects/items/devices/gps.dm

@@ -83,7 +83,7 @@ var/list/GPS_list = list()
 	dat["curr_z_name"] = using_map.get_zlevel_name(curr.z)
 	dat["gps_list"] = list()
 	dat["z_level_detection"] = using_map.get_map_levels(curr.z, long_range)
-
+	
 	for(var/obj/item/device/gps/G in GPS_list - src)
 		if(!G.tracking || G.emped || G.hide_signal)
 			continue