To begin playing with RF I need a signal source, so I built a buffered VCO from Experimental Methods in RF Design. It took a few tries to get a barely functional toner transfer with my clothes iron, so I’m thinking of using UV next time.
I’ll have to look into that saturation at the top of the signal. Also the tuning range is quite narrow (the original design tuned over 50kHz), but I’ll know for sure once I finish the analog front end for my frequency counter.
W. H. Hayward, R. Campbell, and B. Larkin, Experimental Methods in RF Design, Revised 1st Edition edition. Newington, CT: Amer Radio Relay League, 2009.