Belkin TuneCast 3 Antenna Mod...





Introduction: Belkin TuneCast 3 Antenna Mod...

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...

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



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    22 Discussions

    I find also how to remove power auto-off feature ;)

    You need only litle wire and resistor (approximately 40k ohm), and also sharp soldering iron and steady hand...


    Great job on the instructable! I have a question or two though, I'm not into RF transmission myself so it may be dumb to ask why the antenna needs to be grounded? To me that seems it would defeat the purpose. Second, would it be wise to cut the traces of those enemy resistors, as they are connected to ground? And your "C38" resistor is actually a capacitor hence the C not an R, just thought I'd let you know, and not that it matters. Thanks.

    7 replies

    Hi, as far as I know, all forms of antenna are usually grounded, it's how they work, don't know why though (I'm no RF transmission expert myself!!!). As for the C38, actually that does make sense, I just got the "Resistor" name off the site I found showing how to alter the antenna, my electronics limits me to knowing that a big barrel shaped thing or little round pillow shaped thing is a capacitor, SMD components are a little beyond my knowledge, cos they're too tiny for my eyes to read!!! :S I shall amend accordingly though, thanks... :D

    Thanks for replying so soon. From what I can tell from looking around on the internet all of the antennas are grounded, so I decided to leave all the caps and resistors in place and just added a new antenna as per your instructable and it works hundreds of times better. Thanks for posting this instructable, saved me killing my new TK3.

    No problem and I'm glad it works for you too, I do wonder why they limited the range on the TC3 so much, I haven't used one in a vehicle, but if they can barely work in a house, then in a car or van (being a from of Faraday cage), they're probably going to be pretty useless... :\ But still it's easy to solder on a new and longer antenna... :D

    Yeah, I'm not sure why they would make the TK3 capable of greater distances, but limit it. And about the car, I tried it out and it works surprisingly well, I could be anywhere in my van and got crystal clear reception, all on batteries.

    My TC3 works from one end of the house (my bedroom upstairs) to the other (living room downstairs), although the radio has to be set to Mono in the Living room, it still produces a crystal clear transmission, makes me wonder how far it could go!!! :D

    I can get 40 or 50 feet out of mine in a pinch, without having to resort to mono, mind you I did this testing outside, which may have provided less interference then being inside. I really do wonder how far it could go, any idea what the serial connection inside the TC3 could be for?

    I guess with an amplified antenna, it could be comparable with a local radio station's transmitter, but of course, that would end up breaking transmission laws, but still, it has potential... :D As for the serial connection, I'd love to know, maybe it can be used for RDS data, or maybe reprogramming or something, I'm sure someone will work it out... :)

    Yep, although I am not condoning the idea, you could use one as a radio jammer, or as you say, prank someone else's radio by playing really cheesy music through it or disgusting sound effects (diarrhoea sounds come to mind!!! :P ), or just annoy them... :P But as I say, for legal reasons I am not condoning them (just so I and Instructables don't get in trouble!!!)... :)

    This may be a stupid question, but would I be able to use some 14awg speaker wire in place of the 2core wire you used? I have several extra feet lying around.

    3 replies

    You could, but you'd still need to cover the joints with heatshrink tube, aswell as detach the antenna from the attenuated side of the Tx circuit and solder to the output from the Transmitter chip, so you may aswell just solder a new wire in place of the original... :)

    Thank you twocvbloke. Now my Tunecast 3 works as it should have out of the box. I clipped out about a two foot section of black telephone cord for your mod. I had it laying around, was black, and had the two wires per your mod. I also drilled through the side of the white inner case recessed track wire storage wrap area to feed the wire into the unit. My hole choice was a tad bit smaller than the outer wire insulation. Holds and stays put nicely without glue. I've used in three cars now and it works flawlessly. I just sit it anywhere in the car, no fussing about sweet spots at all. In fact, Turns out that the signal can be received well to about three car lengths away. Five or six with static. This was while sitting on my passenger seat. within the metal confines of my car obstructing the line of sight. I was not hanging the antenna out of the window or anything special. Thanks again, Marco Pollo.

    3 replies

    You're very welcome, it's such a simple mod, yet it works so well... :) I read somewhere that if you add a capacitor of some value in there, you can improve the range to quite a distance, haven't tried it myself though, I don't need to set up a pirate radio station!!! :D

    I think the 'notenuator' concept is just fine by me. Perhaps even designed into the product for easy modification. Its a lot easier to remove/bypass a circuit than having to add components to boost it. Its just nice to end up with a product that does what everyone buys it for in the first place. I'm thinking about picking up another, moding it, hooking a mixer to preamp the line level audio from our entertainment center and ending up with a whole house stereo audio relay. Regards, Marco.

    Don't amplify the audio signal too much or it ends up distorted, it's a "fun" job trying to get the audio level just right, too low and it cuts out, too high and it sounds rubbish!!! :S I have been looking into an RDS device and connect it to the TC3, so I can have track names up on the display of RDS receivers, but the chip in the TC3 is apparently (in the words of a radio professional!!!) crap, but still, it's something to try to do!!! :D