I found this: http://www.youtube.com/watch?v=FY3s8OpFbEI

Basically the method seems to be to eliminate power limiting devices for the antenna on your board and then replace the antenna with a better one. There are also power amplifiers (not used in the youtube link) which actually amplify signals. I doubt the FCC will come knocking on your door if you boost the range a bit, but if your neighbors down the street start complaining about interference you might have a problem :D.

Couldn't you just hook up an external antenna and raise that to the top of your roof and broadcast as far as you need it....i found this one Click Here which they say broadcasts 150 feet?

With my little fm transmitter I got from walmart in the automotive section for 12$, I had a range of like 5 feet for clear signal then it diminished from there. Really decent for it's purposes. Ran on 2 AAA.

then, in the last week ive been getting into trying to boost it's signal and google told me that if I attach a ~69mm wire onto one of the terminals where the battery touches, it should boost the signal. I obeyed the almighty google and boom. A huge increase in range. Went from about the 5 feet or so to a distance longer than my house (that's as far as I tested it, it's freezing where I live, don't judge).

Getting greedy, tonight I attempted to bump the power supply, said bollocks to increments and threw on a 12 volt drill battery. BAD IDEA. I know that now. But I'm gonna get a new one, except they no longer carry the EXACT same model.. Although, they carry an updated one (I assume it's updated) so I'll get it and mess around with it then post results!

I saw a link below about FCC compliance.

I did a little research for a project im doing and the FCC non-licenced, "low power" transmitter range is 200 meters, or roughly 210 yards by my crude math.

In layman's terms: you can broadcast any fm signal in a less than 200 meter range that doesn't interfere with you local radio stations.

Here is a good transmitter worth looking at for a first radio project.
http://www.cie-wc.edu/fmtransmitter.asp

::: pls I'm newbie ... leave the antenna i have the circuit of lpfm and NachoMahma says (Even the best antenna isn't going to give you much range with a low-power transmitter) my self-made lpfm range is 25metres, how can i upgrade my lpfm to a high-power transmitter? any1 lead me to a link or some information, i'll be thankful,! :-{)

Hi buddies me too require this,,, but i want to boost the range about 5~10 Kilometers at least ..even transmitter require more power

any use?

claims to be FCC approved

L

here, check this out, this guy seems to have the right idea. he even mentions boosting the power with a AAA battery. i haven't tried it yet, but the diagrams make it look pretty fool proof, even if you don't have the same transmitter he has (i don't).

hope this helps, good luck! I plan on modifying mine tonight. just follow the link below.

http://greensboring.com/viewtopic.php?f=23&t=6351

take luck,
nick

It's possible to increase the range somewhat by changing the antenna. Google it - there are guides out there on how to do it.

Here's a quick thought - if you're trying for range in just one direction, get hold of an old satellite dish. Put your transmitter in place of the old receiver (in the focal point of the parabolic dish), and see what happens.

I'm pretty sure you can't increase the range, there isn't really an antenna (I think), it's just an inductor, which if you change would break the transmitter.

. What kind of range are you looking for? Even the best antenna isn't going to give you much range with a low-power transmitter. . I couldn't find any technical details on the device.