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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: VHF Channels (totally off topic)
From: Lu Abel
Date: 2013 Aug 30, 09:21 -0700
From: Lu Abel
Date: 2013 Aug 30, 09:21 -0700
I'm aware of this page too. It indicates a plan for the future. But it doesn't answer my question of how and when we ended up with two Channels 10 in the USA. We did not have two of them a decade ago.
From: Marcelo S <marc33xx@gmail.com>
To: luabel@ymail.com
Sent: Thursday, August 29, 2013 3:24 PM
Subject: [NavList] Re: VHF Channels (totally off topic)
You can see: http://www.navcen.uscg.gov/?pageName=apps18 The table is adapted from the International Telecommunications Union Radio Regulations Appendix 18, including changes adopted by the 2012 World Radio Conference. Perhaps you should check the ITUR regulations. Until 1 January 2017, in Regions 1 and 3, the existing duplex channels 78, 19, 79 and 20 can continue to be assigned. These channels may be operated as single-frequency channels, subject to coordination with affected administrations. From that date, these channels shall only be assigned as single-frequency channels. However, existing duplex channel assignments may be preserved for coast stations and retained for vessels, subject to coordination with affected administrations. In Region 2 (i.e. N. & S. America), these channels may be operated as single-frequency channels, subject to coordination with affected administrations. regards, marcelo 2013/8/29, Lu Abel : > Marcello: > > I'm quite aware of this page, which shows today's channels (including both > 20 and 20A). > > My question is when 20 was added to the US channels, giving us the unique > situation of having two channel 20s.�� As noted, I have three VHF radios > that don't offer a choice of Channels 20 but I have friends with brand-new > radios that do. > > Lu > > > > > >>________________________________ >> From: Marcelo S >>To: luabel{at}ymail.com >>Sent: Thursday, August 29, 2013 6:07 AM >>Subject: [NavList] Re: VHF Channels (totally off topic) >> >> >> >> >>________________________________ >> >>I am sure you know: http://www.navcen.uscg.gov/?pageName=mtvhf 2013/8/29, >> Lu Abel : >> I live in the San Francisco Bay area and there's this little thing going >> on called the America's Cup. >> >> It's being broadcast on TV (at least here in the USA), usually after a >> two hour delay (ie, after the actual races have concluded so as to not >> draw people away from watching in person shoreside). >> >> The audio from the broadcast, which included real-time reporting and >> commentary by sailing luminaries such as Gary Jobson, is broadcast live >> on Marine VHF frequency 20, so you can actually hear the commentary as >> you watch the races from your boat (as I did a couple of weekends ago). >> >> Here in the US about a third of the VHF radio channels we use are >> different from what the rest of the world uses. Generally they are >> simplex channels whereas their international brothers are duplex. These >> US-unique channels are often designated with an "A" after the channel >> number (for example, to talk to the US Coast Guard, one uses Ch 22A) >> >> Because of this difference, most VHF marine radios come with a switch >> labeled "USA" and "International" that switches between the two sets of >> frequencies. >> >> I got into a confusing argument with several very knowledgeable >> colleagues about the America's Cup broadcasts because they were >> broadcast on Channel 20, not 20A. "That requires switching your radio >> to 'International' to listen, doesn't it?" "No, it's just on my >> radio" I finally discovered that both Channel 20 (duplex) and 20A >> (simplex) are authorized for use in the USA. >> >> I've got a fixed mount radio on my boat and two hand-held VHFs, all of >> which are 10 or more years old. They give me just one choice of VHF >> Channel 20 (which I'm guessing is 20A). (I also just bought a new DSC >> VHF radio, but haven't had a chance to install it and see a 2013 view of >> channels) >> >> Adopting both 20 and 20A for use in the USA seems to be recent. But I >> can find no information about when this change took place. >> >> Does anyone on this list know (or, even better, point to some history on >> the adoption)? >> >> Thanks >> >> Lu >> >> : http://fer3.com/arc/m2.aspx?i=125004 >> >> >> >>: http://fer3.com/arc/m2.aspx?i=125005 >> >> > > : http://fer3.com/arc/m2.aspx?i=125006 > > >: http://fer3.com/arc/m2.aspx?i=125016