If ROS did not use FHSS then only the rules that you quote would apply. The problem is that the table in 97.305(c) authorizes SS only above 222 MHz.
The FCC rules are much more restrictive than ITU treaties. Other countries specify only maximum occupied bandwith in their amateur radio regulations. 73, John KD6OZH ----- Original Message ----- From: w2xj To: digitalradio@yahoogroups.com Sent: Sunday, February 21, 2010 19:17 UTC Subject: Re: [digitalradio] A closer look at ROS] I have spent the last hour looking through part 97. I find nothing that would prohibit ROS in the HF bands subject to adhering to those segments where the bandwidth is allowed. In fact the rules would appear to support such operation: (b) Where authorized by §§ 97.305(c) and 97.307(f) of this part, a station may transmit a RTTY or data emission using an unspecified digital code, except to a station in a country with which the United States does not have an agreement permitting the code to be used. RTTY and data emissions using unspecified digital codes must not be transmitted for the purpose of obscuring the meaning of any communication. When deemed necessary by a District Director to assure compliance with the FCC Rules, a station must: (1) Cease the transmission using the unspecified digital code; (2) Restrict transmissions of any digital code to the extent instructed; (3) Maintain a record, convertible to the original information, of all digital communications transmitted I also do not see anything in the part 97 subsection on spread spectrum ( if in fact ROS was really determined to be an SS mode) that would make ROS non compliant. Part 97 technical standards mostly harmonize US rules with ITU international treaties They are written to be quite broad in order to permit experimentation. So long as the coding technique is public and can be received by anyone, the real restriction is based on allowable bandwidth and power allocated for a given frequency. John B. Stephensen wrote: > The attachments are a good illustration why the rules should be changed. Olivia and ROS use a similar amount of spectrum so the FCC shouldn't be calling one legal and the other illegal based on how they were generated.