Archive for tag: permeability tuned oscillator

M1KTA’s QRP ham radio blog: PTO VFO

January 28, 2010 | Amateur Radio | By: Mark VandeWettering

If you go back through lots of amateur radio designs, you’ll find many, many circuits that use the nearly uniquitous 365pf air spaced variale capacitors that were nearly ubiquitous up until about 25 years ago. In the last couple of decades however, they have become like Avatar’s unobtanium, seemingly impossible (or at least expensive) to […]