Well we had the same problem. Why do you have this effect? It's easy to understand.
First thing the class name of your object is , for this radio, tf_anprc152 and not tf_anprc152_3 ( you certainly found this wrong class on your sqm file or on the editor.
How the sw radio works on task force radio addon :
The task force radio addon works with script which add the information "_X". So when you put for example 5 radio in a box with this command addBackpackCargoGlobal ["tf_anprc152", 5]; the TFR'script will create 5 radio from tf_anprc152_1, tf_anprc152_2; tf_anprc152_3;... These _X number increase till you get your mission on. So normally you should not be able to get two identical radio number.
Hope this information will help you.