6 MHz Oscillator

While I was experimenting with Linrad, I decided that I needed a simple signal generator that would oscillate around six megahertz. I used the oscillator section of an NE612 to make a simple, if not very stable RF oscillator. I used Manhattan construction techniques to build the oscillator on a small piece of single-sided copper clad board. The circular button is used to switch the nine-volt supply. The two trimpots are used for coarse and fine frequency adjustment. I packaged everything into a chocolate Altoids tin, as shown in the pictures below. The circuit board is held down with double-sided foam tape. I quickly learned that the tin-coated steel tin affected the output frequency somewhat. That is why I placed two holes in the lid for frequency adjustment. As I mentioned before, the frequency output was not very stable, but the oscillator was usable enough.