This is the most searched on the internet. By default, the radio is locked to amateur bands. The MARS/CAP mod opens the transmitter to continuous coverage from 1.8 MHz to 54 MHz and 137-174 MHz (receive remains wide open).
For a detailed look at diagnosing and repairing common RF output failures in this model: IC-7400 Lost Power – This Driver Was Cooking! JackieAudio YouTube• Jan 13, 2026 icom ic-7400 mods
The PA is capable of 120-130W, but ICOM set the limiter low for safety. This is the most searched on the internet
: Replacing the faulty Q302 transistor and C302/C303 capacitors with higher-rated components. LED Conversion : Modern kits like those from icom ic-7400 mods