RF frequencies ... (MHz): 300, 315, 390, 433 ...what else ?

Hi all,

I know these frequencies are used by wireless devices like clocks, temperature sensors, garage openers, etc. Is there any other that could be used ?

Thanks

These applications fall under low-power part 15. So, there is no real what to know what freq a low power device will use.

If there is an FCC ID number on the cover, you can use it to look at the FCC database. I have done this several times and found very useful information, including schematics and tech service manuals.

Now some folks, aka Radio Shack do not provide any documetation

Europe is limited to 418 MHz in the UK, 433.92 MHz and double the

U.S. just lets the manufacture select the frequency and it could even be in the FM broadcast band.

One Garage Door Company works on 390 MHz. Very little used frequency just on the edge of 400MHz which is for government military and controlled by NIST.

A nice government "phone cell" clone project appear on 405MHz at Eglin AFB. The thought is that this system will be placed at every base site in the United States.

The 1000 erp power station completely blanked out garage door receivers for over 40 miles.

The GDO company came down and found out about the interference from the government. The item was brought up that they had been on 390 MHz since the beginning (20 years) and would have expected a freq study to have been done before the final frequency range was selected.

And, the company expected that the government would have came out with a notice to manfacturers. This company did a study and determined that over 100 million openers would be impacted.

The case was bought up that the US government should allocate freq bands for this type service, a 1 MHz spread that could be called home.

The comment was that if GDO get a band, then every other peanut powered intenional radiator producer would want a piece.

Ol well, spelling getting bad, it late....

pdrunen

They already have them, don't they? The various ISM bands at 49MHz, ~900MHz, ~2.4GHz, ~5.8GHz, etc. I think what you're really saying is that they want a _protected_ band, which would be difficult to find for every little interest out there.

In this particular case, -- at least from what's been presented -- it does seem that the military should have paid a little more attention to commercial users at 390MHz. Perhaps a better alternative would have been for them to set up a, say, 5-10 year schedule after which they'd glom onto the band -- giving the GDO manufacturers time to get better filtering in place, switch bands, etc.

The rules state that unlicensed use in those bands do not have priority, and must accept interference from licensed services. Any military use that leaves the installation where it is used has to notify the FCC. AFRTS radio and TV stations are issued a "license". The one I worked at in Alaska had a radio and a TV station, and both were recognized by the FCC.

I used to repair the transmitters and receivers for a "Overhead Door Company" dealer in Ohio and the equipment was very poorly designed. Single conversion, tone modulated and broad as a barn. Take a look at what is in the transmitter and receiver these days. It is still the cheapest junk they can build to open the door from 25 feet.