Increase Range of RF devices

Using Arduino Networking, Protocols, and Devices
1

Hi,

I want to make a rc project, so I want to build a submarine. So I found out that lower frequencies are better if I want to communicate under water. I want to use RF communication and no optical as it seems that it is more expensive and needs more experience, but if you know any good lecture feel free to share your knowledge. I would appreciate this. :wink:
But the over water communication and the increasing of the range is more important for my project.
So I am kind of newbie when it comes to real world electronic, so I want to use the RF Link Transmitter - 315MHz found at RF Link Transmitter - 315MHz - WRL-10535 - SparkFun Electronics.
I have found out that I can increase the range by increasing the voltage and/or by adding an antenna.
And as I said I am a newbie to real world electronics and such things, how can I add an antenna to this device. And what an antenna do I need and if you know where can I buy them or find a useful source where the building of one is explained.

I have also found the xbees at sparkfun that really have a quite large range, but I don't want to spend that much money.
And I also have already googled for "315MHz antenna" and such things but then I just found big antennas which are too big for my project and they still have not anwsered my question.

I am looking forward to hear from you. I would really appreciate if you could help me. :slight_smile:

King regards,

Greenality

2

RF does not penetrate water very well for practical purposes for the hobbyist it does not penetrate at all. This topic comes up periodically and usually the person who asked it was not aware of that because it seems so easy, but it is not. When they talk about low frequency radios used for communicating with submarines they are talking much below 300 MHz, they call it extremely low frequency and use antennas that stretch for miles.

wade