Hi, i whant to make a home made Infrared Extender (an emitter and a receiver), here you have a photo of what y need.[Link: crutchfield.com]
if someone can tell me how to built this, i want to connect it to a yamaha rx-v995, please email me!!!!!!!!!
[email protected]

The site you refer to appears to show an infrared LED attached to a cable with a mini-plug on the end of it. This is real easy to make, and can be done with parts bought at Radio Shack. To ensure that the LED does not get fried if it is connected to an output that is not current-limited, there should be a 100 ohm resistor in series with the LED.

I would discourage you from trying to make an IR receiver if you want it to perform as well as professional products. I have watched an engineer design one of these, and it took him a couple of days (with more knowledge than you and I have together) to make it work properly.

However, one approach that might work, or might only work 50% of the time:
Get from Radio Shack:
an IR sensing photocell
an appropriate resistor
a darlington transistor
an IR emitting LED
a 200 ohm to 470 ohm resistor --must be chosen by experiment
a 9 volt power supply

Next, you need to understand how this stuff works. Then, connect the IR sensing photocell and a resistor from +9v to ground. The resistor is chosen so that the output of the photocell swings from ground to about +5 volts DC when you shoot a remote at it. You will be observing this voltage on your oscilloscope.

Then, couple that voltage to the base of the darlington through an appropriate current limiting resistor (choose by experimentation or calculate based on the beta of the input stage).

Use the darlington as an emitter follower, and put the IR emitting LED and its current limiting resistor between the darlington's output and the ground. I just remembered, the darlington may reverse the polarity of the pulses, so maybe this should be a common emitter instead of an emitter follower (common collector).

That should work for relaying IR information from one place to another. The problems you might encounter will be RF interference, pickup of IR outside the IR range, and changing of the signal waveform between the darlington and the IR emitting LED, if the signal has to go very far.