romibraman wrote:
The amplifier diagram above indicate I need at least two resistors of 33r and 220r and I don’t have either. I ve tried with 1 100 r between the E pin of the transistor and ground and no signal at all. I ve tried the same 100r in série between E and my composite cable and no signal at all.
The 2N4401 (in
this schematic) is an NPN transistor. The 2SA937 is a PNP transistor. They are not interchangeable.
The schematic on the NES-001 mainboard instead is this:
Code:
+5 +5
| | +5
510Ω 5600Ω |
| +--C?---+ |/
+--FB--+--- to RF modulator ---10uF--330Ω--+-3.3uH-+--|
|↙ | | |↘
Video In -----| 330pF 330Ω +--68Ω--+-- to RCA to TV
|\ | | 560Ω |
| | | | C?
gnd gnd gnd gnd gnd
You can flip the super-simple schematic over to use a PNP transistor:
Code:
+5V
|
220Ω
|
+--- Video Out
|
33Ω
|
+
|↙
Video In ---|
|\
|
gnd
but note that it'll add a large DC bias. Your TV may or may not object.
Quote:
Another question all my NES and Famicom have this piece called FC2 at the very end of the composite trace. I’m not familiar with it. It looks like a small cylinder. What is it and do I need to add one to my breadboard ?
That's a ferrite bead. It's a tiny inductor. You shouldn't need it for testing.