My menu screen on my TRX-2 shows a "S" instead of a "T" when scanning at times. Radio is truck mounted. My scanner is only scanning trunked systems on Ohio MARCS. When the "S" is present the radio is silent. I have brought along my SDS100 to listen also and it will pick up transmissions when this "S" is displayed on the menu screen. If the "T" is present the radio will receive. The SDS does out perform the TRX-2. And yes only two counites in my area are simulcast and they are about 20 miles apart from each other. I know the "T" stands for Trunked. What does the "S" represent and can it be avoided somehow? Or is it another mode I may not be familiar with?