Computer mod part 2 [ Radio station for the computer ]

Post by **floodhound2** » 07 May 2007, 10:51

My Computer Radio Station

This is a “medium level of difficulty” project so beginners need to consider this.

This baby runs around 100-108 MHZ that is easily received on any Fm radio. I made it to transmit my MP3’s running on my computer to my FM radio downstairs while I clean house.

I needed to make this Computer Radio Station powered off my spare fan slot on my motherboard so 12 Volts was considered first during design. I currently have it wired so that the input signal plugs directly into the speaker output port on the back of the computer. However this week I am going to use the header pins on the mother board [used for headphones on the front of the computer] to connect to, so that I can still use the speaker port on the back of the mother board. I just need to find my mother board manual.

I have a parts list here and a schematic for you to follow if you wish to take this project on.

Code: Select all

R1	56K
R2	1M
R3	1.2K
R4	1K
R5	1K POT
R6	220K
R7	22
R8	100K

C1	100pF
C2	100uF
C3	1nF
C4	4.7uF
C5	4pF
C6	1nF
C7	22pF Adjustable Cap
C8	15pF
C9	5.6pF

Q1	2N3819
Q2	BC557B
Q3	BF245A

D1	BB909A
D2	1N4148

You will need a proto board to solder all the parts to. Antenna is any wire 4”-32” long. Once you assemble it you just need to tune the adjustable capacitor and pot until signal is received on radio.

In the future I would like to address the PCI port and make a full PCI card radio transmitter. So if you know how to program the PCI port using the sound features like a sound card uses let me know.

Please ask question and ill do my best to help.

Post by **bad_brain** » 07 May 2007, 12:06

saweet man!

btw, what app have you used for the circuit diagram? I want to post some of my diagrams too...I have some nice ones for powerfilters (actually for HiFi equipment, but good for computers too), tube amplifiers I built, and maybe for tesla coils (have to think about that, pretty dangerous stuff).
I tried a plugin for LaTex on Linux, but it's a little too complicated...

Post by **floodhound2** » 07 May 2007, 13:31

First of all I am running the app in windows. It is called Multisims Electronic Workbench. I also use Eagle to design boards and do a little schematic work. Nice thing about Multisims is you can simulate the circuit bad thing is it cost around $2000 – $5000 American. Nice thing about Eagle is it is free for a few weeks bad thing is it is weak for schematics. PM me and I can help on both.