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    Re: Shortwave radio and the evolution of celestial navigation
    From: Francis Upchurch
    Date: 2018 Jun 13, 08:44 +0100

    I've just re-read JS Letcher's Self Contained Cel Nav. The bit where he 
    refused to take a radio for time signals, relying on his one and only 
    aircraft 8 day clock.
    After a month at sea, approaching Hawaii, he got a bit worried about his 
    longitude and so taught himself lunars to check his clock.
    I would not recommend this approach myself, but my pretend test runs using 
    lunars +/- my mechanical watch suggest it would be ok in extremis. I've also  
    done a few "no clock " lunars and got to within 10-20 miles Longitude, but 
    definitely this just for fun.
    -----Original Message-----
    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Hewitt Schlereth
    Sent: 12 June 2018 23:01
    To: francis{at}pharmout.co.uk
    Subject: [NavList] Re: Shortwave radio and the evolution of celestial navigation
    Yeah, Francis, time signals at sea are a great comfort. My first offshore 
    passages in the early 70s were made with an Omega Seamaster self winding 
    watch and a specialized s/w receiver called a Time Kube from Radio Shack - 
    just WWV broadcasts. In 1976 I splurged and bought an early (clunky) Seiko 
    digital, but continued to carry the TK.
    On Jun 12, 2018, at 1:15 PM, Francis Upchurch  wrote:
    I think you are right. 
    I have spoken to a couple of old local Penzance sea salt friends recently on 
    this. They both did the "milk run" UK-Canaries-West Indies-Azores-UK in the 
    late 1960s-early 1970s. Usually 24 ft wooden type semi seaworthy boats.) 
    Mostly using only meridian passages, no intercept method (far too 
    complicated!). What they needed was cheap quartz watches and SW radio time 
    signals. (not necessarily Sony transistors. Ordinary cheap valve jobs or 
    crystal sets would do). For simple trade wind sailing this would do fine and 
    probably still would?
    So quartz watch and SW radio time signals received by whatever primitive 
    receiver technology would do. I guess if you had the radio time signal, you 
    do not even need the quartz watch. 
    My wonderful Invicta cheap mechanical copy of the Rolex submariner has kept 
    +3-8 seconds going rate consistently for the last 2 years (checked daily and 
    never outside this range) and would easily win the longitude prize. This plus 
    any cheap  radio time signal (transistor or otherwise, even crystal sets, my 
    experiments a few years ago prove this. Do not even need batteries for 
    these.)  Would do fine.
    Trade wind sailing no problem with the simplest of equipment. Good mechanical 
    watch + time signal from simple SW radio. (Unless , like me you are a 
    lunatic! No watch time needed! No radio needed.). Lunars would do it.(just).
    -----Original Message-----
    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Frank Reed
    Sent: 12 June 2018 20:16
    To: francis{at}pharmout.co.uk
    Subject: [NavList] Shortwave radio and the evolution of celestial navigation
    Bob Goethe, suggesting an addition to Ed's chronology, wrote a few days ago:
    "*I think the combination of transistor shortwave radios, station WWV, and 
    Seiko's quartz watch is what finally allowed the St. Hilaire intercept-method 
    to come into its own among small boat sailors.*"
    This is an interesting hypothesis. Bob, could you elaborate on your thinking 
    here? Can you think of any evidence that would support this model? Does 
    anyone else have thoughts on this? Did WWV really change things when it came 
    on the air? There were other radio time signals. How about shortwave 
    transistor radios? Transistor radios were more expensive than tube radios for 
    quite a few years. I do agree that quartz watches made celestial navigation 
    cheaper and therefore more accessible, but that seems like one modest 
    innovation among many in the 1950s and 1960s. 
    One suggestion: I think you should drop any mention of the intercept method, 
    per se, when describing this hypothesis. That strikes me as essentially 
    irrelevant to the issue that you're raising, and surely the intercept method 
    was the primary method of celestial navigation taught to the tens of 
    thousands of new navigators created in the Second World War, well before the 
    solid state electronics revolution.
    Maybe this hypothesis should be considered in connection with a bigger 
    question. What made bluewater sailing more accessible in the past fifty 
    years? Was it some change in celestial navigation, or were other factors 
    really key?
    Frank Reed
    [plain text auto-generated]
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