External RF Power Control for 2m/70cm Handhelds

Most modern handheld transceivers for 2 m and 70 cms ham radio incorporate MOSFET RF power modules and are capable of operating at supply voltages between 4.5 V and 13.8 V. When using four NiCd batteries (4.8 V), RF power on high power mode (H) is typically 1.8 watts. When using a 9.6 V battery pack, the H power level is typically 5 watts, while 500 mW or 50 mW is produced in L (low power) and EL (economicallow) mode, respectively.