Everything you need to “homebrew build” a complete 40M (7.0 - 7.2 MHz) VFO (Variable Frequency Oscillator)

This new kit from Hollow-State Designs is a complete “homebrew” thermatron VFO that covers the 40 meter amateur band from 7.00 go 7.20+ (the CW portion and much of the SSB/AM portion). In the spirit of our Thermatron Michigan Mighty Mite (MMM), this is a simple to build project with everything provided including all hardware, parts, even the superglue. 

This VFO/LO is the first of our 3 kit DCR (direct conversion receiver), providing the receiver band tuning.  The kit can also be used to supply a 4 Vp-p stable signal to a homebrew transmitter (such as the TMMM) or as a LO in your next receiver project.  It uses a common 6U8A pentode/triode. The pentode is the Hartley oscillator with a triode cathode follower.  Like our TMMM, this kit was created to familiarize new and existing hams with simple thermatron (vacuum-tube) homebrew construction techniques.

The VFO needs a minimum of 160V DC at 25mA, and 6.3V AC for filaments.  The kit was designed to use our HV PS which outputs 190V DC and 6.3V AC (also available on eBay).

Complete step-by-step assembly instruactions are available on my YouTube channel: www.youtube.com/@graysonevans4496