I'm wondering if I have a unique, or at least very rare system: The ONLY way I can obtain satisfactory DCS operation is to use the SPEED option rather than the NORMAL option....Under NORMAL, I typically see responses like, OUT OF RF RANGE; not always, but much too frequently. Another example: Hit QUICK SPEED, then enter the desired new speed. Usually I DO get the desired speed, but the window does not change: It continues to display QUICK SPEED. Several more pushings of the thumb wheel are required to finally get the proper screen...... + many more examples, such as whistle-blowing, that I'll not mention!!
I believe that I am well-aware of the 'theoretical' differences between these 2 options, which leads me to offer my hypothesis as to the cause of the NORMAL problem: For some strange reason, the last leg of a DCS command sequence, that from the TIU back to the remote, is not operating correctly.....most of the time; not always.