identificationreverse-engineeringRF
I've got this 3GHz RF amplifier off ebay, and I'm trying to figure out how it works. I've took the RF shield off, but the markings on the component that I assume is the transistor, are scratched off.
What transistor could have been used here?
Also, how can this thing work with just one transistor?
Here is a photo of my device:
The underside of the PCB is just a ground pour
It looks a lot like a 2SC945, whose TO92 packaging matches the image you posted.
It seems this potentiometer belongs to the F10KV6 series by Favor (or Polyshine). It falls under the category of "rotary joystick potentiometers". The form factor seems to be the same as the original (even though the resistance could be different). The ultimate confirmation would be to obtain one, but since the minimum order quantity from the suppliers found is 1000 units this is unlikely.
SE Note: Since this is along the lines of the information I was hoping to obtain I am posting this as an answer rather than a comment. If it is inappropriate for me to do this, feel free to take whatever corrective action is necessary.
http://www.switches.co.kr/f10kv6.htm
http://www.alibaba.com/product-gs/717840000/10mm_Joystick_Rotary_Potentiometer_F10KV6.html
Best Answer
The schematic of the circuit is as follows:
simulate this circuit – Schematic created using CircuitLab
U1 appears to be an integrated RF amplifier, not a transistor. I imagine that any transistor in an amplifier like this would require a DC path on all 3 of its terminals, whereas pin P1 is open at DC, so a transistor would work very poorly and wouldn't really amplify much.