I agree; that's what I call type three overload:Unless you're within a stone's throw of a TV Tower...and maybe not even then....I don't think you can PHYSICALLY DAMAGE a Preamp (or TV Tuner) input with "TOO" strong a signal.
3. The signals are so strong that the input transistor is toast. You are not likely to encounter OTA signals that strong, unless you live next door to a high power transmitter and you have your high gain antenna aimed at the transmitter's antenna.
The closest I ever got to that was +9 dBm (+58 dBmV) out of a CM3410, when I fed its input -6 dBm (+43 dBmV), which means it hadn't gone into compression yet.Highest TVFool I've ever seen is about -10 dBm....plus Antenna Gain....yields about 0 dBm signal, which is only ONE MILLIWATT. It would take somewhat MORE THAN 1 Volt on the input of the RF Transistor to actually DAMAGE it (MOSFET/HEMT typ. 5-10 VDC, perhaps 1-3 VDC with low-voltage Integrated Silicon Tuners). If Max Input was 1 VDC, this would be MORE than 13 mW (V^2/R), which is MORE THAN +10 dBm....NOT gonna happen.....
http://www.digitalhome.ca/forum/showpost.php?p=1597002&postcount=3490