Dane.Kouttron

FM Audio Transmitter [Combined L&R]

Project: Need cheap FM transmitter because Tape deck is broken 

What? 

Build a quick FM transmitter to listen to your tunes on amything equipped with a radio

Why?

This was done because i wanted to listen to a portable device over the radio and the next best alternative was too exhorbatantly priced (seriously, 20 dollars? why?)

1. Starting from a blank piece of copper. As shown, its slightly tarnished from being stuck in the basement for a while,
2. Using some simple scotch-brite (i guess a brillo pad/super light sandpaper would work) clean the copper. It increases surface area and allows for a better transfer of toner
3. Print out your pcb layout. This layout came from a design i did in free pcb. i basically took a screenshot, inverted it (black- white), threw it in photoshop, flipped it (left->right) and printed it out through a toner based printer. after printing it out onto normal paper, i taped a piece of toner transfer paper onto the paper, ran it through the printer again and ended up with the circuit (inverted) on toner transfer paper.
4. place your cleaned copper pcb board onto something solid that can withstand heat (i used a tile) and tape your toner transfer printout onto the copper. use painters/masking tape. it can withstand the heat and it doesnt melt like electrical / duct tape. firmly press the whole thing, (using your mom's clothes iron) together for approximatley 2 minutes.
5. Cut your design out of the copper board and dunk it in ferric chloride (you can order it online, get ripped off by getting it at radioshack, or check out this instructable on making your own

So, put your etchant into some kind of jar that can withstand some chemical abuse and that your board can fit into
(plastic majo jar). close the lid tight, put on some gloves and shake the * out of the jar. after 3 minutes, the copper is eaten away and you get your board.
6. And lo, theres your board. now tack the required components on and wham, fm transmitter


Wheres All The Technical Stuff?

1 Heres the schematic. its right out of a maxim ic appnote. The appnote was moved from online, hopefully by mistake
2 Local Link to the printout of the circuit LINK
3 Local Link to a copy of the appnote (maxim-IC.com) LINK









Dane.Kouttron
Rensselaer Polytechnic Institute 
Electrical & Electrical Power
631.978.1650

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