David, Greeting.
Recently, we have active discussion of FreeDV operating frequencies based on the fact that Japanese regulation body allows the operation of Digital Voice on 160 meter from 1.845MHz to 1.875MHz and JA FreeDV activities have been increasing by 700D introduction. Then, I found IARU R3 band plans defines Digital Voice COA as follows. https://www.iaru-r2.org/wp-content/uploads/2020/02/IARU-Region-3-Band-plan.pdf CoA: “Centre of Activity” frequency (IARU recommended) 7070kHz, 14130kHz, 18160kHz, 21180kHz, 24960kHz, 28330kHz Digital Voice: Any mode based on digital encoded voice, restricted to the specified bandwidth and application of the frequency segment. The non-voice digital embedded content must be an ancillary data, not the main purpose of the communication, except during emergency communications. Digital Voice users should first check if the channel is already in use by other stations and modes (including analog) >From above information, I can say 1. We can respect IARU recommended CoA as our FreeDV operation frequency if IARU globally provides the protection to CoA FreeDV stations. 2. Unfortunately, R3 band plan does not include 80m and 160m CoAs. Therefore, we have the opportunity to provide the recommendation to IARU if we have common CoA of FreeDV. 3. Large discrepancy exists between IARU recommended CoAs and actual FreeDV operation frequencies such as “Presets” in FreeDV QSO Finder i.e. “28.7200, 24.9330, 21.3130, 18.1190, 14.2400, 14.2360, 7.1900, 7.1770, 5.4035, 3.8170, 3.7320, 1.9970”. Obviously, we have to recognize the local environments and can not exactly follow IARU recommended CoAs. For example, we can not operate 60m band and we can not operate above 1.875MHz at 160 meter band and therefore, 5.4035 and 1.9970 must be eliminated from CoA in Japan. 4. We have to examine which is better for JA FreeDV to prioritize IARU CoAs or FreeDV QSO Finder frequencies. So far, it looks like the decision can be made by JA FreeDV users but I wish to know the above items are satisfactory for you to start our discussion. I am happy to receive your comments soon. Regards, take de JA5AEA Windows 10 版のメール<https://go.microsoft.com/fwlink/?LinkId=550986>から送信
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