Ryan KJ7KVD is building a Michigan Mighty Mite. I sent him some parts, and mentioned that I had redrawn the schematic. I find that it sometimes helps me understand a circuit if I just re-draw the schematic.
Above you will see what I came up with. Here is what I told Ryan:
Attached is my re-daw of the MMM schematic. The emitter and base resistors just needed some clarification. The original schematic led some to believe that the two resistors should be connected. Not so! I think the redraw clarifies this.
The most significant re-draw is in the coil. All I have really done is to "pull out" the tapped "tickler" coil. You will read in the literature that the two are equivalent. This just shows that L1 can be seen as a separate coil, imparting RF to the parallel LC tank circuit that is tuned to the operating frequency. The phase shifts introduced by the transistor, the tank, and the crystal all add up to the needed value in order to meet the Barkhausen criteria: Oscillation results!
Go ahead and build the coil with the tap as in the original schematic. This re-draw may help you understand how the thing works. Understanding is important.
Here is one of the orignial schematics (from https://www.qsl.net/wb5ude/kc6wdk/transmitter.html):
I like your redraw(in pencil ✏️ no less!) Orientation of the grounds at the bottom helps me. The lower drawing style always bugs me whenever I see it, I usually redraw those too . Lately, because I do almost exclusively Manhattan construction, I put my grounds anywhere convenient on the copper clad, so too now with my hand drawn schematics. I'm not cluttering the schetch. So liberating!
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