6.78 MHz ISM band worldwide? - Page 1
Forum section: electronics / projects

author: hughes_k
author_rank: Contributor
timestamp: May 16, 2014, 04:56:11 am
content: I've been tasked with determining the pros/cons of each of the sub-100MHz ISM bands for a new project at work. One factor is that we don't want to have to worry about running into regional radio emissions issues should we expand the product beyond the US.I have not been able to find a resource detailing, comprehensively, the worldwide radio band designations. Actually, I haven't been able to do much better than the Wikipedia article on ISM bands, which includes the following (subset of a) table:Center freq Availability6.780 MHz Subject to local acceptance13.560 MHz Worldwide27.120 MHz Worldwide40.680 MHz WorldwideThat's fine, except for the 6.78 "subject to local acceptance". Can anyone clarify this or (hopefully) point me to some more meaningful resource?Thanks!

author: Unknown
author_rank: Unknown
timestamp: May 16, 2014, 05:10:35 am
content: If you want the exact details, you'll probably have to trawl through theITU Radio Regulations. Article 5 (in Vol. 1) would be the place to start.(edit: Looks like 5.138 is the list of ISM bands which may require local authorisation.)

author: amyk
author_rank: Super Contributor
timestamp: May 16, 2014, 12:04:30 pm
content: Why not just use 13.56 or the other worldwide ones?

author: hughes_k
author_rank: Contributor
timestamp: May 16, 2014, 04:05:43 pm
content: Quote from: amyk on May 16, 2014, 12:04:30 pmBecause, if it were available, 6.78 would lighten the switching load on FETs and other components..Quote from: Tac Eht Xilef on May 16, 2014, 05:10:35 amThanks for the link - hoping there's a curated list or table that would make this easier. Do you know whether, in the full 4-volume set of regs, there are explicit listings for where each band is and isn't ISM?

author: Unknown
author_rank: Unknown
timestamp: May 17, 2014, 01:41:12 am
content: Quote from: hughes_k on May 16, 2014, 04:05:43 pmI can't recall ever seeing a comprehensive list anywhere for any of the the ISM bands, let alone 6.78MHz, and it'd pretty much have to be compiled by collating each country's regs.And from your original Q:Quote from: hughes_k on May 16, 2014, 04:56:11 amIt's not quite as open-slather as that though; you still have to stick to local spectral & power restrictions which can & do vary between countries even for the same ISM band. For example, 2.4GHz class-licenced spread-spectrum devices with >1MHz BW (e.g. WiFi) are limited to 5mW EIRP in France, 100mW in most of Europe, 500mW in Australia, etc.; non-spread-spectrum devices with >1MHz BW are allowed (I think) 10W in Europe, 4W in Aus, etc. I'd expect any local regulations for 6.78MHz to be more stringent than that due to the potential for local & long-distance interference.

author: vk6zgo
author_rank: Super Contributor
timestamp: May 17, 2014, 03:08:55 am
content: Quote from: hughes_k on May 16, 2014, 04:56:11 amI wouldn't totally trust Wikipedia---they do get things wrong from time to time.For instance,even if a frequency is available in your target country,the local Authorities may insist on you supplying a sample unit for them to test.You would check other things,like import regulations,taxes,etc on a country by country basis,so why not this as well?

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: May 17, 2014, 04:17:13 am
content: Here in Australia you'd need to look up the Low Interference Potential Devices Class Licence on acma.gov.au

author: hughes_k
author_rank: Contributor
timestamp: May 26, 2014, 04:49:44 pm
content: Thanks for all the replies so far...appreciate the resource recommendations - I'll get to reading