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!!!
I find also how to remove power auto-off feature ;)<br>https://www.instructables.com/id/Tunecast-3-Turnin-auto-off-off-C52/<br><br>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.
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... :)
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.
It might be a touch thick for the task, but I don't see why you couldnt... :)
excellent, thanks for the quick response...I'll have a go at it later today
No problem, have fun... :D
Can't you just splice and add length to the existing antenna wire?
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.
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
We are all a bunch of DIY junkies. We appreciate any Instructable relatively easy to understand and informative. I tried a Belkin Tunecast II in my car so I could play my Podcasts through the car radio. Reception from the Belkin by the radio was not a problem, static and interference was. If you found a way to overcome those things and get a nice, clean signal to the radio as the car is driven in and out of sources of interference; I would be grateful. I have thought about shielding on the Belkin's output, but have not tried it. Mostly, I went back to a cassette style car kit in my car's tape drive. Congratulations on your first Instructable.
The only way I can think of to remove external sources of interference is to unplug the external mounted car antenna and replace it with a very short length of wire on the back of the radio, but this isn't as easy as it is for me and my bed radio, the only other way is to have a transmitter that over-powers local stations, but this could end up being illegal, though my mod, if you increase the length of the antenna to a metre, is good at this, I managed to reach the railway station across from where I live, that's quite a distance, so I trimmed the antenna down to just 50cm... :) There is an instructable on the TC2 on how to fit a telescoping antenna (it's in the "Related" list), you could adapt this with a wire antenna, as I find a wire antenna easier to stow away, and this should improve your TC2... :) The main interference I get with my TC3 is actually from my laptop's screen inverter, but that's probably just down to my bodged job of fitting a 14.1" screen in a 15" laptop... :P

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