diff --git a/hud.lua b/hud.lua
index 6f3dca7..63d3bf1 100644
--- a/hud.lua
+++ b/hud.lua
@@ -74,12 +74,11 @@ function ham_radio:update_hud_display(player)
   local name = player:get_player_name()
   local meta = player:get_wielded_item():get_meta()
   local frequency = meta:get_string("frequency")
-  
+
   if frequency ~= nil and frequency ~= "" then
-    local transmitters = self.read_transmitters(frequency)
-    
-    for key, transmitter in pairs(transmitters) do
-      local transmitter_signal = self:locate_transmitter(player, transmitter.pos)
+    local transmitters = self.find_transmitters(frequency)
+    for position, transmitter in pairs(transmitters) do
+      local transmitter_signal = self:locate_transmitter(player, minetest.string_to_pos(position))
       if transmitter_signal > signal_power then
         -- use max power from transmitters nearby
         signal_power = transmitter_signal
diff --git a/init.lua b/init.lua
index 0c8d0b0..586886d 100644
--- a/init.lua
+++ b/init.lua
@@ -11,35 +11,31 @@ ham_radio = {
   }
 }
 
-function ham_radio.save_transmitter(frequency, pos, transmitter_properties)
-  local transmitters = mod_storage:get_string(tostring(frequency))
+function ham_radio.save_transmitter(pos, transmitter_properties)
+  mod_storage:set_string(
+    minetest.pos_to_string(pos, 0),
+    minetest.write_json(transmitter_properties)
+  )
+end
+
+function ham_radio.read_transmitter(pos)
+  return mod_storage:get_string(minetest.pos_to_string(pos, 0))
+end
+
+function ham_radio.find_transmitters(frequency)
   local transmitter_list = {}
-  if transmitters ~= "" then
-    transmitter_list = minetest.parse_json(transmitters)
-  end
-  transmitter_list[minetest.pos_to_string(pos, 0)] = transmitter_properties
-  mod_storage:set_string(tostring(frequency), minetest.write_json(transmitter_list))
-end
-
-function ham_radio.read_transmitters(frequency)
-  local transmitters = mod_storage:get_string(tostring(frequency))
-  if transmitters ~= "" then
-    return minetest.parse_json(transmitters)
-  end
-  return {}
-end
-
-function ham_radio.delete_transmitter(frequency, pos)
-  local transmitters = mod_storage:get_string(tostring(frequency))
-  if transmitters ~= "" then
-    local transmitter_list = minetest.parse_json(transmitters)
-    transmitter_list[minetest.pos_to_string(pos, 0)] = nil
-    if next(transmitter_list) == nil then
-      mod_storage:set_string(tostring(frequency),"")
-    else
-      mod_storage:set_string(tostring(frequency), minetest.write_json(transmitter_list))
+  local all_transmitters = mod_storage:to_table().fields
+  for key, transmitter_data in pairs(all_transmitters) do
+    local transmitter = minetest.parse_json(transmitter_data)
+    if transmitter.frequency == frequency then
+      transmitter_list[key] = transmitter
     end
   end
+  return transmitter_list
+end
+
+function ham_radio.delete_transmitter(pos)
+  mod_storage:set_string(minetest.pos_to_string(pos, 0), '')
 end
 
 dofile(modpath.."/craft.lua")
diff --git a/transmitter.lua b/transmitter.lua
index 63fa06f..bb467cd 100644
--- a/transmitter.lua
+++ b/transmitter.lua
@@ -37,10 +37,9 @@ minetest.register_node("ham_radio:transmitter", {
       meta:set_string("frequency", fields.frequency)
       meta:set_string("infotext", 'Frequency: '..fields.frequency)
       ham_radio.save_transmitter(
-        fields.frequency,
         pos,
         {
-          pos = pos,
+          frequency = fields.frequency,
           broadcast_message = "Test Ham Radio Broadcast!",
           operated_by = meta:get_string('operated_by')
         }
@@ -54,6 +53,6 @@ minetest.register_node("ham_radio:transmitter", {
     return inv:is_empty("main") and not minetest.is_protected(pos, name)
   end,
   after_dig_node = function(pos, oldnode, oldmetadata, player)
-    ham_radio.delete_transmitter(oldmetadata.fields.frequency, pos)
+    ham_radio.delete_transmitter(pos)
   end
 });