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Subject: Re: [M]: No periodic error ?
From: Paul Luckas
Reply To: mapug@shore.net
Date: Tue May 01 17:43:06 2001
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The mount is about 15 years old - the optics are a bit younger (I bought =
it in two stages). Originally I also had a 12.5 inch Newtonian on it, =
but the tube size was unmanageable (at f6 it was a looooong tube) so I =
opted for the much more portable 8 inch assembly. You can imagine how =
stable it is on this massive mount.
(for those interested: http://web.one.net.au/~paul_luckas) Apologies in =
advance for the image upload times.
It definitely has no periodic error correction capability - ie, it's a =
very simple arrangement (synchronous motor, worm and wheel - that's it). =
I have an original Meade drive corrector - the old 'joy stick' type, =
which I still think are much better (easier to use) than the push button =
variety, but that's it. I appear not to have any periodic error to train =
out !
Thanks Wayne,
Paul
----- Original Message -----=20
From: Wayne Watson=20
Sent: Wednesday, May 02, 2001 2:20 AM
Subject: Re: [M]: No periodic error ?
Yes, that's quite good. How old is the unit? I have access to one that =
is about 15 years old (a 12.5") and I do not believe it has PEC training =
available. It's not completely functional, and was donated to our local =
museum.=20
You are doing quite well if you trained out the PEC. I spent about 1 =
hour training and updating my PEC on my LX-200 8" f/10 and could see a =
slight crawl over 8 minutes. I don't know what it amounted to in arc =
seconds. I'm using a 12.5mm Celestron graduated eyepiece. I could see =
drift from the top of the 3 in '30' to the top of the 0. That's about =
one graduated unit on the scale. I'll probably erase and try again =
tonight. It seems like near zero should be possible.=20
Paul Luckas wrote:=20
Is there such a thing as no periodic error ? I've just spent that =
past few evenings engaged in accurate polar alignment of my aging Meade =
Research Series Newtonian. I've cancelled all of the declination drift =
out, and am now trying to ascertain the periodic error of the old RA =
drive. I've been tracking Achernar (yes, I'm in the southern hemisphere) =
for the past hour, and have not been able to see any drift whatsoever in =
a 9mm illuminated reticle eyepiece. Notwithstanding the excellent (if I =
do say so myself) polar alignment which has accounted for the zero drift =
in dec., is it possible that Meade manufactured sub-arcsecond accurate =
RA drives way back in the 70's ? I'm impressed to say the least. BTW: I =
"was" thinking of selling the unit to buy an LX200 - =
(http://web.one.net.au/~paul_luckas), but now I'm having second thoughts =
? =20
--=20
Wayne T. Watson (121.015 Deg. W, 39.262 Deg. N, 2,701 =
feet)=20
He allus said, "Don't take life too serious, it ain't nohow =
permanent."=20
- Walt Kelly, Pogo=20
Web Page: http://home.earthlink.net/~mtnviews=20
=20
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4613.1700" name=3DGENERATOR></HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>The mount is about 15 years old - the =
optics are a=20
bit younger (I bought it in two stages). Originally I also had a 12.5 =
inch=20
Newtonian on it, but the tube size was unmanageable (at f6 it was a =
looooong=20
tube) so I opted for the much more portable 8 inch assembly. You can =
imagine how=20
stable it is on this massive mount.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>(for those interested: <A=20
href=3D"http://web.one.net.au/~paul_luckas">http://web.one.net.au/~paul_l=
uckas</A>)=20
Apologies in advance for the image upload times.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>It definitely has no periodic error =
correction=20
capability - ie, it's a very simple arrangement (synchronous motor, =
worm=20
and wheel - that's it). I have an original Meade drive corrector - the =
old 'joy=20
stick' type, which I still think are much better (easier to use) than =
the push=20
button variety, but that's it. I appear not to have any periodic error =
to train=20
out !</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Thanks Wayne,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Paul</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
Watson</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Wednesday, May 02, 2001 =
2:20=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [M]: No periodic =
error=20
?</DIV>
<DIV><BR></DIV>Yes, that's quite good. How old is the unit? I have =
access to=20
one that is about 15 years old (a 12.5") and I do not believe it has =
PEC=20
training available. It's not completely functional, and was donated to =
our=20
local museum.=20
<P>You are doing quite well if you trained out the PEC. I spent about =
1 hour=20
training and updating my PEC on my LX-200 8" f/10 and could see a =
slight crawl=20
over 8 minutes. I don't know what it amounted to in arc seconds. I'm =
using a=20
12.5mm Celestron graduated eyepiece. I could see drift from the top of =
the 3=20
in '30' to the top of the 0. That's about one graduated unit on the =
scale.=20
I'll probably erase and try again tonight. It seems like near zero =
should be=20
possible.=20
<P>Paul Luckas wrote:=20
<BLOCKQUOTE TYPE=3D"CITE">
<STYLE></STYLE>
<FONT face=3DArial><FONT size=3D-1>Is there such a thing as no =
periodic error=20
?</FONT></FONT> <FONT face=3DArial><FONT size=3D-1>I've just =
spent that=20
past few evenings engaged in accurate polar alignment of my aging =
Meade=20
Research Series Newtonian. I've cancelled all of the declination =
drift out,=20
and am now trying to ascertain the periodic error of the old RA =
drive. I've=20
been tracking Achernar (yes, I'm in the southern hemisphere) for the =
past=20
hour, and have not been able to see any drift whatsoever in a 9mm=20
illuminated reticle eyepiece. Notwithstanding the excellent (if I do =
say so=20
myself) polar alignment which has accounted for the zero drift in =
dec., is=20
it possible that Meade manufactured sub-arcsecond accurate RA drives =
way=20
back in the 70's ?</FONT></FONT> <FONT face=3DArial><FONT =
size=3D-1>I'm=20
impressed to say the least.</FONT></FONT> <FONT =
face=3DArial><FONT=20
size=3D-1>BTW: I "was" thinking of selling the unit to buy an LX200 =
- (<A=20
=
href=3D"http://web.one.net.au/~paul_luckas">http://web.one.net.au/~paul_l=
uckas</A>),=20
but now I'm having second thoughts =
?</FONT></FONT> </BLOCKQUOTE>
<P>-- =
<BR> =20
Wayne T. Watson (121.015 Deg. W, 39.262 Deg. N, 2,701 feet)=20
<P> He allus said, "Don't =
take life=20
too serious, it ain't nohow permanent."=20
=
<BR> &nb=
sp; &nbs=
p; =20
- Walt Kelly, Pogo=20
=
<P> &nbs=
p; =20
Web Page: <A=20
=
href=3D"http://home.earthlink.net/~mtnviews">http://home.earthlink.net/~m=
tnviews</A>=20
<BR> </P></BLOCKQUOTE></BODY></HTML>
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