Here is a photo of my Elecraft K2/100 which I built in 2006!! I have had the radio for many years now, and it still works perfectly. The receiver is a single conversion superhetrodyne type, and it is nice and quiet thanks to the well designed low-noise synthesizer in the radio. This is indeed reflected in the lack of “White noise” from the speaker during receive.

Here is the unit with the 100W Power Amplifier attached. The amplifier uses 2 x 2SC2879A RF Bipolar transistors, which are capable of 100W each! (The ALC circuit in the radio prevents more than 100W or so being produced in total). This amplifier is only ever running at 50% of capacity at most, which improves the longevity of the output devices. The T/R switching is solid state, so there is a H/V supply in the amplifier to provide the necessary reverse biasing for the non-conducting diodes during switching.

Another picture of the radio with the PA….

Here is the unit after installing the KDSP2 module – a very worthy addition to the radio – and it is open source!

In conclusion, though this radio was frightfully expensive to buy and build, I consider it to be well worthwhile – as I suspect that I learned more from this build than I ever could have from any textbook or tertiary course.

73 and take care.

Jamie, VK2TIM