Heathkit VHF-UHF Bidirectional RF Wattmeter IM-4190 Power Ranges Forward (Full Scale) 30, 75 and 100 Watts. Reflected: 3, 7.5 and 30 Watts. 300 Watts Max Frequency Range: 100 MHz to 1 GHz. Impedance 50 Ohms. N type connectors. (Two adapters to allow use of HF connectors).