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Re: Q-Par positioner (was Re: Free Microwave Calculator)



Hi Clifford,
    The 338 mm is the capability of my equipment. It doesen't have to be
made that large if you dont want to but it would give better resolution
particularly if you consider it will probably be the IR leds and sensors
which will limit the resolution. At 2400 DPI to get 0.1 Degree resolution
the disc only needs to be 25mm diameter! The problem with that size is being
able to sence such a small area.
    I noted that Hannes, OE5JLF used epoxy discs to support the Laser
Printer - Transperancys he uses and the film would be mechanically similiar
to this. The film can be cut with a pair of scissors and so maybe I could
produce images on film for 16 encoders with the LSB on the outside (as
normal) and those who want to save space and didn't need the resolution
could simply cut the "bits" of they don't want. (16 bit is a resolution of
0.005 Degree - probably useful for telescopes but insignificant for any
antenna that any amateur has that I know of).
Regards,
Murray Peterson
VK2KGM
Sydney, NSW,
Australia

----- Original Message -----
From: "Clifford Buttschardt" <cbuttsch@slonet.org>
To: "Murray Peterson VK2KGM" <vk2kgm@ihug.com.au>
Cc: "AMSAT-BB" <amsat-bb@AMSAT.Org>; "Ross Biggar" <rbiggar@ihug.co.nz>
Sent: Monday, January 15, 2001 12:38 PM
Subject: Re: [amsat-bb] Q-Par positioner (was Re: Free Microwave Calculator)


> That would be fine Murray.  We need to get individuals in each major
> country involved in such reproduction.  I first did not realize that the
> disk was that large.  So be it!  The larger the better as we can handle
> the imperfections better.  I am going to try and locate a Autocad teacher
> at a local Community College and go from there.  With cooperation, this
> problem will fall as many others have.  Cliff K7RR
>
>
> On Mon, 15 Jan 2001, Murray Peterson  VK2KGM wrote:
>
> > I have the capability to go from computer to polyester based (very
> > dimentionally stable) photographic film 338mm across so I should be able
to
> > produce an optical encoder which could be bonded to, say glass.
> >     My system is an AgfaPro 9800 ImageSetter usually used for producing
> > negatives for printing plates etc. It has a resolution of 2400 DPI.
> >
> >     At least this might be worth thinking about as on way of doing it.
> >
> > Regards,
> > Murray Peterson
> > VK2KGM
> > Sydney, NSW,
> > Australia
> >
> > ----- Original Message -----
> > From: "Ross Biggar" <rbiggar@ihug.co.nz>
> > To: "Cliff Buttschardt" <cbuttsch@slonet.org>; "Louis A. Mamakos"
> > <louie@TransSys.COM>; <karn@ka9q.net>; <antonio@qualcomm.com>
> > Cc: "Phil Karn" <karn@ka9q.net>; <antonio@qualcomm.com>;
> > <amsat-bb@AMSAT.Org>
> > Sent: Sunday, January 14, 2001 7:43 AM
> > Subject: Re: [amsat-bb] Q-Par positioner (was Re: Free Microwave
Calculator)
> >
> >
> > >   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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> > >
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> > >
> >
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> >
>
>

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