Referring to my bible, "Solid State Design" by Hayward and DeMaw, I expected a gain of 17dB from the circuit below:
I achieved this 17dB of gain at 10MHz. However, the gain had fallen by 4dB at 20MHz so at present I will limit my use of this transistor to 14MHz and lower.
My clip on heatsink was a 15mm x 15mm piece of circuit board, held on with a wooden clothes peg. Worked extremely well for testing but I have a more permanent solution in mind which I will post about shortly.
Overall a nice little amplifier and I will box it up for use on the workbench to increase the drive from my signal generator as required. But ironical that it will be a 15c transistor between two expensive BNC connectors.
With 8 transistors left I will really push them in the next experiment to see if there is any smoke in them!
I found this post searching for anyone who's tried the 2SC5707 in an RF power amplifier. Did your experimentation with this transistor pan out? Looking at the specs, it looks very similar to the classic 2SC2078 of CB radio fame... just with a much higher gain bandwidth product. I was thinking about playing with it, since it's still in production, and was curious if you took it any farther.
ReplyDeleteHi Jason
DeleteI did not take this much further than outlined above. The fabrication of a heatsink for an extended test was taking longer than the time I had available. I was able to confirm to my satisfaction that this is a useful device and if you try it I'd like to hear how you got on.