English to Romanian Tech/Engineering Telecom(munications) Construction Information

Stage 2 comprises of two field effect transistors (FETs), as previously stated no negative feedback is provided giving a stage gain of about 23dB, providing ¼ watt of drive to the output stage. FETs are broadband devices, if driven from a constant voltage source their output can be expected to be flat across the HF band. Unfortunately FETs have a relatively high input capacitance, in the case of the RD06HHF1s used here it is about 27pF giving a capacitive reactance of 196 Ohms @ 30Mhz. Rather than trying to provide a broad-band match to this reactance it is simpler just to load the gate with a resistor of much smaller value, this does of course limit the stage gain but to me 23dB is still quite adequate! Q2 and Q3 gates are loaded with 100R resistors, these also provide a DC path for the ***** bias voltage.*****