This one is following in the line of other Belkin TuneCast mods, but this is for the current version, which I call the TC3... :)

I am not responsible for creating this mod, I found it through searching the web, and I have customised it to my needs and style.

This is where I found the mod originally...
http://dreamlayers.blogspot.com/2008/09/simple-belkin-tunecast-3-mod-to-boost.html

Please note, this is a modification of FM transmission equipment, increasing the range of a range-limited device may not be legal in your location, so do this entirely at your own risk, if men in dark suits come knocking, it is not my fault!!!

(Thanks to vandmatt who reminded me that C means capacitor and R means resistor when it comes to labelling on the circuit board... :) )

Step 1: The TuneCast3

First off, this is the TuneCast3 (note: I modified mine well before this Instructable, so this is an image of the finished product), it is a nice, sleek device, it has a frequency range of 88.1 to 107.9Mhz FM, it has 2 memory presets and you can change between Stereo or Mono, which handy to increase the range (mono) or quality (stereo).

The display is a neat OLED display, it's nice and clear in both the dark and bright sunshine, but all you need to do is set your frequency and that's that... :)

Anyway, on with the show...

Step 2: Open It Up...

To open up your TC3, take off the back cover, revealing the batteries, and either side of the batteries are 2 + head screws, take these out and set them aside.

Next, take a flat screwdriver or blade between the white plastic and the front case and carefully prise it open, it will pop off easily, just be careful not to slip and damage the wires inside...

And that's it, you're in...

Step 3: Have a Look About...

Ok, in the pictures, you can see the layout of the TC3's innards, I have drawn in the red antenna wire on the 2nd one, yours should look something like this, and this is the red wire you will be replacing.

Step 4: Time for Soldering...

Ok, heat up your soldering iron (low temperature, if you can set the temp. that is, I have a gas powered iron so I set it low), and remove the red antenna wire. Stick it in a spares drawer or box, you never know when you might need a little red wire to make a connection... ;)

Step 5: Prepare the Antenna...

Get yourself a length of 2-core wire, strip it back about an inch (3cm), then, if applicable, strip off 1/4 inch (5mm) of sheath from the 2 wires (if it is coated wire, just take a lighter and burn off the coating). Next, tin the wire with solder, making sure it's a thin layer.

Next, at the other end, strip off any length, but keeping it short, and solder the two wires together, then cover with heatshrink tubing, that's the anttena sorted...

(I used a cloth braided wire pulled off a set of cheap headphones, cos it looked good, but you can use anything that is fairly slim (so you can wrap it up with the audio wire)... :) )

Step 6: Prepare the Case...

This one is the fun part, not!!! Cut a hole into the front part of the casing, anywhere you like, but make it big enough to pass the antenna wire through, and if you are being neat, file it down with sandpaper or a file, I didn't bother as I'm not that fussed about it... :)

Step 7: Fit the Antenna...

Now, here comes the actual fun bit, fitting your new antenna!!! :D

Heat up your soldering iron, low heat again, and look for the BH1418FV chip, this is the FM transmitter, as Pin 12 of the chip is the RF-output, the resistors and attenuator are your enemy, therefore, you need to bypass these by soldering your antenna to the "C38" capacitor on the chip-side of the component, that's one part done. Next, take the other wire and solder it to where the other end of original red antenna was, and that's it, your new antenna is fitted!!!

Step 8: Test & Close Up Your TC3...

Before closing up, test your TC3, as you don't want to find that nothing happens or it melts into a pile of goo (not likely!!), pick a free frequency on a nearby radio, power up the TC3 and check that it sends out a nice, silent, static-free signal, if it does, all is well.

Switch off, tie a knot in the antenna with a generous amount of wire inside the unit, keeping the knot inside the case close up, just clip it back together and re-insert the two screws, and everything is ready to go... :D

Step 9: TIme for Tunes!!!

Now, just plug the audio cable into your favourite music device (PC/Laptop, MP3 player, cassette, minidisc or, ugh, ipod (me no like!!!)), power up the TC3, set your music playing and adjust the volume until you have no distortion (not too low or the TC3 will cut out), and you're sorted, you now should have a much wider range, so you can use multiple radios, rather than just one within 2 inches of the TC3!!!

You could probably attach a telescopic antenna, but, unlike the TC2, there isn't a place to easily attach it to the casing, and the wire antenna can be stowed away with the audio cable, keeping the unit as compact as it originally was.

Hope this helps, cos it's my first Instructable, and after reading many of other people's Instructables, I thought I should have a go at posting my own... :D

TTFN... :D