Dieter, > Can I use any frequency if my transmission level is below the class B > limit?
No. You can find the current version of the United States' FCC 47 CFR Part 15 at http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&; SID=c4968cff34d29b7b13d674c04d8392b8&rgn=div5&view=text& node=47:1.0.1.1.16&idno=47#47:1.0.1.1.16.3.234.2 Subpart C (currently 15.201 through 15.257) covers Intentional Radiators. 15.205(a) covers Restricted bands of operation, and says "Except as shown in paragraph (d) of this section, only spurious emissions are permitted in any of the frequency bands listed below". 15.207(a) has the Conducted limits for Intentional Radiators. These are identical to the Class B Conducted limits for Unintentional Radiators in 15.107(a). 15.209(a) has the Radiated emission limits; general requirements for Intentional Radiators. These start at 9kHz. At 30MHz and higher they are identical to the Class B Radiated limits for Unintentional Radiators in 15.109(a). Canada has similar requirements. RSS-Gen Issue 3, dated December 2010 http://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/rssgen-i3.pdf/$file/ rssgen-i3.pdf with NOTICE 2012-DRS0126 http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10224.html covers Radio Apparatus. Table 3 on page 22 lists Restricted Frequency Bands. Table 4 on page 23 specifies the AC Power Line Conducted Emissions Limits, which are identical to FCC 47 CFR Pat 15 15.207(a). Tables 5 and 6 on page 24 specify the General Field Strength Limits for Transmitters, which are identical to FCC 47 CFR Part 15 15.209(a) for the electric field strength, but add magnetic field strength limits for 9 to 1,705kHz. John Barnes KS4GL, PE, NCE, NCT, ESDC Eng, ESDC Tech, PSE, Master EMC Design Eng, SM IEEE dBi Corporation http://www.dbicorporation.com/ - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
