AUTOSTAR INFORMATION Last updated: 22 March 2002

Autostar Accuracy Tests

Sent:	Friday, March 22, 2002 11:00:28
From:	AntonyM@tesco.net (AntonyM)
From:   Brian Mellors, London.   England.
                c/o   AntonyM@tesco.net    ( reply taken )

Thanks for publishing your super book, it might have saved me 75 dollars
having my ETX125 serviced, to try and improve pointing.  I bought a
second 497 AutoStar, but both work about the same.

SUGGESTION:  On how to sort out the ETX / AutoStar.

1.  Make alphabetical list of brightest stars above Mag 2,
   say less than 30 stars.   List coordinates Mag, 
   Constellation and Star Map page.  This should give
   AutoStar alignment stars 1 and 2.

2.  Find out how good your ETX AutoStar is at star pointing.
    The accuracy and repeatability should be about one field
    of view   about 1 degree Dec  and 5 minutes RA    
     ie,   one small division on scope scales.

METHOD.

Put scope on a table, pretend it is outside the home,  level, and
pointing North. Switch on scope and go through first 2 star alignment
procedure. WRITE DOWN coordinates from scope scales, and make a list if
alignment is satisfactory on AutoStar.   Switch off and repeat about 10
times  - it will take about an hour.

Plot results of coordinates on graph paper -  Dec. in degrees, 20-90
degrees at top of sheet,  RA in Hours and Minutes at bottom of sheet.  
IF ALL YOUR RESULTS LINE UP WITH THE REAL STAR COORDINATES,  -
Wonderful,  - you have a good scope that you can take outside and have
fun,  BECAUSE YOU KNOW IT WORKS OK.







But,  if your results are spread out any old where like mine,  you may
have to forget all about AutoStar.  Use the hand controller and do
Astronomy the old fashioned way,   use the Dec  and RA scales,  and
drive it to the star coordinates. Below are my results for "Capella" and
"Vega", each of 50 tests.

Are we expecting observatory level performance for a peanuts price? It
would have been great if my AutoStar worked,  but that is life, I
guess..!
                   Brian Mellors.  London.  March, 2002.

N.B.  Brian is giving a small talk to his Astronomical Society, -
    "On Starting with my Meade Scope",   - next Thursday 28th March.
If you are able to make comments before then,  I will see he gets
them straightaway.     Regards.   His pal,  Tony.

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