The apple Ipod Itrip FM transmiter is very weak. It's not powerful enough to be useful in a car, where it is geared towards. By adding a bigger antena you can effectively increase the signal strength.
I bought an Itrip about a year ago thinking it would really make my life easier while driving. I connected it up and started using it and realized how crappy it was. A year went by and i decided to crack it open. I figured it couldn't hurt to play with it since i wasn't using it. I beefed up the antenna and found a great improvment in quality and signal strength.
This hack is fairly easy. Probably the hardest thing involved is getting the case open. They sealed it pretty well. The antenna that it comes with is a single length of copper wire that runs the length of the itrip, needless to say thats freakin weak!! there are plenty of ways to attach a better antena. The easiest way is to coil a copper wire in a spring and slide it over the existing antena. extendin outside the plastic case couldn't hurt either.
What you'll need
- Length of copper wire not insulated (i used around 3 or 4 feet, but guess and check is the best way to go)
- wire cutters
- very thin and sharp utility knife
- dremel tool (optional)
- heat shrink tube (optional)
- big paper clip
- super glue or plastic weld
- candle or small heat source
1. Open the case - Probably the hardest step is the first one, cracking the case open. It took me a few trys before i got it. You have to dig your utility knife down a seam pretty deep at first. There are four pegs on the corners and one by the jack in the bottom. You can cut these but its better not to so it fits together better in the end. Slip the knife in the seam all the way through. When you are all the way in you need to apply a good about of force to start it to slide down the seam. Do this on all for sides and it should crack right open. Be careful of the circuit board and of your fingers, its real easy to slip with such a small work piece.
2. Coil the wire - take your paper clip and bend one the the leads extendeing straight out. Begin wrapping the copper wire forming a very tight coil. The length of coil is realy up to you and what you want to do with it. Mine is alittle shorter the the existing antena.
3. Slip the coil on - slip the coil over the existing antenna.
4. Heat shrink the antenna - place a length of heat shrink tube over the new antenna. I used white tube so it wouldn't look bad comming out of the top of the case. Use a small candle or heat source to shrink the tubing around the antena securing it in place.
5. Antenna placement - At this point you have to decided wether its going back into the case or are you going to extend it out of the case. I chose to extended it out, if you don't want to do that skip to closing the case. You are going to need a small hole in the top of your case to extend the antenna through. I just used my wire clippers and a utility knife to nip a hole and then clean up the edges. You should probably use a dremel tool for a clean and finished hole, but lets be honest, I'm lazy.
6. Closing the case - Do an initial fit check of all circuit and antenna inside the case before closing it for good. You might want to check and make sure it still works with your ipod as well, its possible the circuit could be busted from opening the case. With everything inside dab on some super glue on the seams and hold it tight until it drys. I used a product called Plastic Weld which is specificly designed for melding plastic together, no residue and no chance of sticking your fingers together. I'd dab on some super glue around the antenna if it is sticking out just to be safe.
Sources and inspiration
There are plenty of websites I've found who show this technique and how well it works. To be honest, I haven't really tested it out in my car yet to concur with them, but it does do a good job in my room and a clock radio. I will say that they don't give a lot of explanation to opening the case.
I think it would be cool to integrate the FM transmitter into other devices, not just the Ipod, i havnt looked into it at all though.