A General Purpose 2N5109 Amplifier
DIY KIT: The 52x52 mm PCB is empty, all the components are supplied but need soldering and the transformer winding according to the pdf file with the instructions
Use it as a receive pre-amp, post mixer amp, ssb tx driver etc.
This is a well known transistor for many old hams. You can see it appearing in recent designs too. It is a nice transistor and you can build a nice linear amplifier with low noise figure (3...3.5 dB), high linearity, high dynamic range and much of stability.
My implementation is shown in the following schematic diagram. It is biased at 60mA and has a different feedback circuit. It's gain is around 14.5 dB, including the output 6 dB attenuator loss and it is broadband for more than 110 MHZ. Good for terminating a mixer's IF port.
It's output P1dB is +23dBm and this makes it suitable for driving a high-level mixer LO port as well.
The photo shows a 10 MHZ signal with input power of +3 dBm while the output is + 17 dBm.
If you need it built & tested please email.
ATTENTION: Change R3 from 390 Ohm to 1800 Ohm in order to establish proper input impedance and gain.