I thought i would introduce myself... Tim Senecal, from Arvada, Colorado, USA. :)
I was pointed at this thread via the posting that David F put on model boat mayhem. I am happy to hear that the 433/459mhz stuff appears to be working well for you.
i simply wanted to add that most of my current posting on this topic is being done at
specifically in the technology section
it appears i am not able to post links for a few more days, so i will add links later if you would like.
I have been working on two fronts as far as 433 stuff goes...
1) much like David, i feel that the antennas that the devices come with are pretty low-end, and have been buying and building/testing new ones. All the FPV guys are raving about a $30 antenna called the "Nagoya NA-771". so i bought one, and i feel making my own is both less expensive, and better performing. I have made several half-wave and quarter-wave antennas, and find my home made quarter-wave work well. in addition, since you guys in the UK are not actually running at 433mhz, i think you will probably have to make your own antennas if you want them tuned correctly for 458/459mhz... that is a small difference, but it ends up being about 1/2" or 1cm difference in length of a quarter-wave antenna. I have basically been using the online antenna calculators, and using the lengths indicated. I have not been adjusting for water. don't know if that helps you any.
2) telemetry. i bought a bunch of the FrSky telemetry Hubs (FSH-01), and have wired up harnesses to allow me to connect them to the 433mhz receivers, as well as harnesses that allow me to connect the FrSky display (FLD-02) to the transmitter module. I am now getting battery voltage, amperage, temperature, and signal strength. soon i will be adding motor rpms and ultimately depth. activating the telemetry gives me very simple signal strength readings - "RSSI", which have improved my ability to make my own antennas.
as to what Hermann says, I did some investigation earlier... I believe that Germany has the strictest rules of all euro nations, and 433 specifically resides within 3 different areas of regulation. LPD433, ISM, and CEPT - "European Conference of Postal and Telecommunications Administrations", which is basically the European equivalent of the US's HAM.... but stricter. IF you have a CEPT license (and not a novice license, but a full license) you will be able to use the full 1watt 433mhz systems. but only if you have the CEPT license.
as to the ISM 10mw output limit... i know the HopeRF module the 433 systems use has power output settings, and the Chrome Configurator allows you to set them. level 3 on a 100mw system would actually be outputting 6-7mw... Testing at that level to see what amount of penetration it gives is certainly possible. interesting enough, the HopeRF module these use was designed for use in ISM equipment.