My friend gave me two versions of this oscillator to use in the 40/80. They both gave a flat output over their operating range. I have a 6 volt lantern battery which was damaged (dropped I suppose). I took it apart and found one cell was shorted. The connecting strap was against the zinc shell. So I have 3 1.5 volt cells about half again as large as a D cell. I'm thing a 1.5 volt radio. A direct conversion receiver with an oscillator feeding a DBM and a a hearing aid amp audio section.
This is the original circuit.
This is what I'm starting the build with. I am using a germanium transistor for 1.5 volt version.
The number 1 issue with the direct conversion set is the oscillator will feed the antenna so I am thinking a ferrite core to help reduce undesired coupling.
Time to try a build.