Whistler receiver
Here is the schematic for the dual FET whistler receiver as a PDF file.
The original inspiration for this receiver was a design by G.W. Forgey. The current design incorporates a number of improvements over the first version I built.
My design objectives for this version of the receiver were as follows:
- minimize front end overload for lower distortion
- use simple RC RF filter before any active components
- include 60 Hz trap before any active components (very helpful in urban settings!)
- dual FET front end
- provides high input impedance
- voltage gain of about 100
- low battery drain
- use a single, 9-volt battery supply
- separate power switch for headphone amp (LM386)
- passive filters (switchable) to reduce active components
- record-out independent of headphone volume
- pay attention to layout and shielding to minimize feedback problems
- integrate the camera-tripod mount into the case
