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Posted by John Davis on May 31, 2023 at 07:52:17.
In Reply to: Re: Powerful RTTY on 22 m posted by Ed Holland on May 30, 2023 at 21:32:18.
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The maximum detectable range for RFID devices in this band would be comparable to the kind of range our hobby transmissions if we were using similar data rates. They operate under the exact same Part 15 rules that we do. It's what the Part 15 rules were written to cover; and why it's not correct to refer to 22 m as an "ISM band," because the ISM rules are not the ones under which we operate. Plasma tools and diathermy devices have no field strength limits under Part 18 (other than the RF exposure safety limits), but have tight certification requirements and cannot be used to carry information. Fortunately, the need for relatively high efficiency in most ISM gear, plus the relative ease of maintaining frequency near the band center these days, confines most of the resulting cacophony to a narrow portion of the available band. It blankets the farthest reaches of the continent all day and much of the night, but still allow an adequate S/N ratio for near-field data and hobby comms elsewhere in the shared band.
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