F
Franklin
- Jan 1, 1970
- 0
I'm quite new to Electronics, and have been working on understanding
an AM radio circuit. I think I've gotten most of it, but I'm stuck at
a few points.
The schematic can be seen at
http://support.radioshack.com/support_games/doc60/60245.htm , or, for
a better picture, at
http://support.radioshack.com/support_games/doc64/64800.pdf .
Here are my questions:
A) Block (1) - I recognize the tuned circuit, but its not in any
configuration that I'm familiar with. Normally, I've seen the signal
come in, and a tuned circuit bypass to ground, and then signal out.
Here, I don't see any signal in (where does the antenna connect to?)
or signal out - only to ground. How is this working?
B) Why is an inductor used to couple to Q1?
C) There are several capacitors which bypass to ground along the way -
from right to left, a 0.1uF, a 0.01uF, another 0.01uF, and a 0.05uF.
Are these all used to detect the AM - that is, to let the HF drop to
ground while the audio carries through? Why do you need so many?
D) Block (4) - How can you couple with only a 0.022uF capacitor -
won't this block all but the lowest frequencies?
Can anyone help me with any of these questions?
an AM radio circuit. I think I've gotten most of it, but I'm stuck at
a few points.
The schematic can be seen at
http://support.radioshack.com/support_games/doc60/60245.htm , or, for
a better picture, at
http://support.radioshack.com/support_games/doc64/64800.pdf .
Here are my questions:
A) Block (1) - I recognize the tuned circuit, but its not in any
configuration that I'm familiar with. Normally, I've seen the signal
come in, and a tuned circuit bypass to ground, and then signal out.
Here, I don't see any signal in (where does the antenna connect to?)
or signal out - only to ground. How is this working?
B) Why is an inductor used to couple to Q1?
C) There are several capacitors which bypass to ground along the way -
from right to left, a 0.1uF, a 0.01uF, another 0.01uF, and a 0.05uF.
Are these all used to detect the AM - that is, to let the HF drop to
ground while the audio carries through? Why do you need so many?
D) Block (4) - How can you couple with only a 0.022uF capacitor -
won't this block all but the lowest frequencies?
Can anyone help me with any of these questions?