Re: [amsat-bb] Q-Par positioner (was Re: Free Microwave Calculator)

["Ross Biggar" <rbiggar@xxxxxxxxxx>]

  Cliff and others, can you count me in on this project as well please, I
have been looking for this kind of item for years for accurately tracking
ham satellites and HRPT using a 2 meter dish.
Phil. Do you know what happened to John Dubois W1HDX is he still alive?

Regards
Ross Biggar
ZL1WN

----- Original Message -----
From: "Cliff Buttschardt" <cbuttsch@slonet.org>
To: "Louis A. Mamakos" <louie@TransSys.COM>
Cc: "Phil Karn" <karn@ka9q.net>; <antonio@qualcomm.com>;
<amsat-bb@AMSAT.Org>
Sent: Saturday, January 13, 2001 6:18 PM
Subject: Re: [amsat-bb] Q-Par positioner (was Re: Free Microwave Calculator)


 > Louis, some VERY good suggestions here.  It would seem to me
 > that we could construct a 4000 bit digital encoder rather
 > easily.  I am thinking of a three trace Gray code wheel, very
 > large in diameter as compared to little commercial ones.  Who
 > cares that the encoder is six inches in diameter when steering
 > and antenna many feet long!  There has to be a photographic
 > master somewhere that will do this job.  Anyone know where?
 >  Cliff K7RR
 >
 > "Louis A. Mamakos" wrote:
 > >
 > > May I suggest that you take a look at the "dob driver" web page at
 > > http://zebu.uoregon.edu/~mbartels/altaz/altaz.html which describes
 > > a system used to position (and track) a dobsonian telescope mount,
 > > which is an az-el mount.  While certainly not the shape required to
 > > position antennas, there are a bunch of resources on stepper motors,
 > > software, drivers, etc.  This might give you some ideas.
 > >
 > > 4000 step optical shaft encoders are widely used in the amateur
 > > astronomy community;  see http://www.usdigital.com/products/index.shtml
 > > for one of the popular manufacturers of devices commonly used.
 > >
 > > See http://whizzo.transsys.com/louie/astro/equipment/ for pictures
 > > of my scopes and mount; in particular in this image,
 > > http://whizzo.transsys.com/louie/astro/equipment/DCP_0868.JPG
 > > you can see the RA shaft encoder, which is driven off a gear from
 > > the RA axis of the Losmandy G-11 mount.  Another approach is used
 > > on a Vixen GP-DX mount where a rubber belt couples the optical
 > > shaft encoder to the telescope mount; see
 > > http://whizzo.transsys.com/louie/astro/equipment/DCP_0866.JPG and
 > > look for the encoder on the counter-weight shaft, above the weights.
 > >
 > > You can also see the small size of the "computer", which is just a
little
 > > box with a 20 character LED display.  (Can't use LCD's; they get
 > > cold and sluggish when the temperature drops too cold, when only
 > > crazy amateur astronomers are outside).
 > >
 > > louie
 > > wa3ymh
 > >
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