camediaman posted:
<< Can someone explain to me the following fm oscillator
http://www.geocities.com/myelectronicsrevision/fmosc.jpg
No need to explain the audio section, just the oscillator, what kind of
oscillator is it, where is the input/output/feedback, what are these thick
lines - is it waveguide technology, what is the equivalent component, is it a
transformer?---
NOT in order of the questions:
• The type of oscillator is Hartley.
• The thick lines are strip-line inductors
cut into one side of a 2-sided board.
The longer one is equivalent to a multi-turn
coil, tapped at about 25% from the bottom.
The smaller, is equivalent to a 1 turn coil
(a "link") adjacent to the top end of the larger
inductor.
• Output is from the small inductor (the link)
at the point designated "ANT"(enna).
• Feedback is from the inductor's tap, to T1's source.
• Is it waveguide technology? hmmm! tough question...
Waveguides and other technologies cross each other
at many junctures, and stripline was probably first
in microwave circuits, some of which have striplines
within waveguides, but I don't think I would consider
striplines to be waveguide technology. It is too
broadly used elsewhere.
• The "input" is audio. I'd say the input is where R2
connects to D1.
• Equivalent component: Use coil inductors as described
above. I estimate the larger inductor should be about
0.25 uH end-to-end. All the other parts and values
are fine.
Don