Hi Andrew,
As Bob Terwilliger pointed out, I made a sundial out of a wall satellite dish
some years ago. I published the results and method in:
J. Davis: Satellites and sundials, BSS Bulletin, 11(ii), pp.77-80, (1999).
My dish was one of the old Astra analogue ones and was a perforated off-axis
parabaloid which both reclined and declined. I made the 'dial plate' from a
plastic skin stretched over the perimeter of the dish, partly to avoid the
perforations and partly to get a flat surface (simpler to work with but not
strictly necessary). Although I calculated the hourlines and gnomon positions,
I used a laser trigon to define the declination lines - this was written up in:
J. Davis: A lightweight laser trigon for layout of sundial lines, BSS
Bulletin, 11(iii), pp.144-146, (1999).
I could probably dig out photographs for you - still on 35mm film at that
date! Sadly, with the move to a different dish for the digital satellite
signals, my dial is now languishing in a pile in the garage. It was an
interesting exercise though!
Regards,
John Davis
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> Greetings all,
>
> Several months ago I bought a house and the previous owners left me with
one of those 12"
> diameter satellite dishes. I have no need or want of Direct TV or satellite
TV.
>
> I was sitting there thinking one day that it would make a really nice
direct south facing sundial.
> My house already faces a little east of south anyway, and the location
where the dish is gets
> direct sunlight almost all year round.
>
> My questions is this: Do I need to make any adjustment in the
calculationsofthe hour lines for
> the shape of the dish? If so what is the formula?
>
> I am going to install a simple style using a metal road about a half inch
in diameter. I want this
> sundial to tell solar time not necessarily actual time. Though one day I
may install an equation of
> time underneat the dial .
>
> Boardwalk for $500? In 2007? Ha!
> Play Monopoly Here and Now (it's updated for today's economy) at Yahoo!
Games.
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