Since FDIM 2010 is in the history books, it is my pleasure to finally publicly release my entry into the FDIM 2010 QRP Challenge: The Clackamas 40 Meter Transceiver.
The rig is a VXO-tuned superhet that operates around 7.030 MHz. The heart of the design is the BF998 dual-gate MOSFET (which was popularized by W7ZOI on his website and in EMRFD). The BF998 is used as the front-end mixer and as a combination product detector/BFO. My new favorite AF amp, the TDA7052, is my choice for the single allowed IC. The VXO signal is mixed with a carrier oscillator in a JFET mixer, which is then bandpass filtered and fed to a BS170 power amplifier.
Please download my contest writeup for full details of the design. I’ll dissect the design in further detail in future posts.
3 thoughts on “The Clackamas QRP Transceiver”
Thank you Jason for allowing us to see the design. What you did with the BF998 is quite clever!
Not sure what I love more, your ideas and designs, or the documentation showing all of it! Definitely a Master of Both!!!
Thanks Mikey, you are far too kind.
I have a 2yr old and in school full time to 22 credits this quarter … so i feel your pain.
Wish you didn’t close the comments though …