diff --git a/helpers.lua b/helpers.lua
index 6e732ad..65f1bb4 100644
--- a/helpers.lua
+++ b/helpers.lua
@@ -30,16 +30,6 @@ function ham_radio.validate_frequency(frequency, is_receiver)
   return { result = result, message = message }
 end
 
-function ham_radio.find_transmitters(frequency)
-  local transmitter_list = {}
-  for key, transmitter in pairs(ham_radio.transmitters) do
-    if transmitter.frequency == frequency then
-      transmitter_list[key] = transmitter
-    end
-  end
-  return transmitter_list
-end
-
 function ham_radio.find_free_frequency(range)
   local frequency = -1
   while frequency == -1 do
diff --git a/init.lua b/init.lua
index fed9d7d..ac5d4ac 100644
--- a/init.lua
+++ b/init.lua
@@ -11,10 +11,15 @@ ham_radio = {
   transmitters = {},
 }
 
--- preload transmitter data
-local all_transmitters = mod_storage:to_table().fields
-for key, transmitter_data in pairs(all_transmitters) do
-  ham_radio.transmitters[key] = minetest.parse_json(transmitter_data)
+function ham_radio.find_transmitters(frequency)
+  local transmitter_list = {}
+  local all_transmitters = mod_storage:to_table().fields
+  for key, transmitter_data in pairs(all_transmitters) do
+    if transmitter_data.frequency == frequency then
+      transmitter_list[key] = transmitter_data
+    end
+  end
+  return transmitter_list
 end
 
 function ham_radio.save_transmitter(pos, meta)
@@ -24,13 +29,11 @@ function ham_radio.save_transmitter(pos, meta)
     operated_by = meta:get_string("operated_by")
   }
   local key = minetest.pos_to_string(pos, 0)
-  ham_radio.transmitters[key] = transmitter_properties -- cache
   mod_storage:set_string(key, minetest.write_json(transmitter_properties)) -- storage
 end
 
 function ham_radio.delete_transmitter(pos)
   local key = minetest.pos_to_string(pos, 0)
-  ham_radio.transmitters[key] = nil -- cache
   mod_storage:set_string(key, '') -- storage
 end