EMRFD Message Archive 15271

Message Date From Subject
15271 2019-05-10 09:55:55 mvtgcmotzj4yrql42... What is the gain of this amplifier?
This is an UHF amplifier amplifying a LO signal on 404 MHz. What is the method of calculating the gain of this amp?

One way to calculate the gain of a common emitter amp IIRC is G = Rc / Re.
However, there is no resistor in the emitter.

Is it correct that inhernet emmitter resistance Re = 26/Ie in milliamps?
So the G = (the reactance of L1) / (26/Ie)

Next question: what common UHF transistor can replace the BFS17A? (I belive this is obsolete)

15272 2019-05-10 10:00:38 mvtgcmotzj4yrql42... Re: What is the gain of this amplifier?
The voltage on the hot side of the R5 resistor is by the way 8V