The justification here in the USA for access to 60 meters was that emergency nets (particularly hurricane nets in the American southeast) found their range too short on 75 meters during the day and the typical 40 meter short-skip range was too long for communications in the 50 to 100 mile range.
Daytime range on 75 is limited by ionization of the lower atmosphere by the sun's radiation, which absorbs RF. 60 meters has significantly less ionization loss and, as you know 40 meters has even less, which allows stable communications in the 100 to 500 mile skip zone in the daytime. Overnight, that skip steadily increases as lower atmospheric ionization fades without the sun's radiation on 40. However, that ionization helps maintain a short skip range throughout most of the night on 60 meters. Of course it all varies according to solar activity. 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:[email protected]] On Behalf Of Johnny Siu Sent: Wednesday, March 2, 2016 12:52 AM To: Elecraft Subject: [Elecraft] OT: 60m band - usual communication range Dear Elecrafters, Local telecommunication authority is considering 60m operation for the hams in VR2. For output power of 15W PEP, using a dipole for NVIS, what would be the likely usual communication range 7/24 round the clock? 100km radius? Any advice will be appreciated and thanks for the band width here. 73 Johnny VR2XMC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
