I plan to investigate the Trask (N7ZWY) KISS mixer. Here’s my first experiment.
Above — I lacked many of the specified parts such as the Fairchild FSA3157 and those expensive MCL transformers, but made do with a dual FET bus switch, the CBT3306.
The LO transistor switch + D flip-flop come right out of EMRFD.
I recently ordered some parts to asses more KISS mixer variants including the FSA3157 and also stocked up on some obsolete, but very fast 74F series logic including the 74F04 and 74F74 that will clock up to 125 MHz or so.
Above — The FET bus switch evaluated as a mixer. The LO and RF are ~ 35 dB down @ the IF port. You can see tones at ~ 12 and 14 MHz — I’ve got to get used to working with digital circuitry in my RF mixers.
Above — IIP3 measure with the tones 40.5 KHz apart. All three of my 2 tone test signal generators feature very low phase noise.
Above 3 — KISS mixer breadboard photo. Again, to provide proper RF ground for all output frequencies, I employ double-sided copper board with copper via wires around and especially adjacent to every pin that requires RF ground. I found this may improve mixer balance and even IIP3 depending on frequency.
