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Subject: Re: Is this a smart smart drive?
From: Robert Fields
Reply To: mapug@shore.net
Date: Sun Jun 18 08:56:30 1995
THis is a very interesting post. I'm a little confused about what the
scales on your graph are. Could label the axis and repost ?
Also, at the end of the message you list the raw data. I'm only seeing
about 2 minutes error over 24 hours, not your reported 24 min/day. What
am I missing ?
I'm currently running Ralphs program on my 10" LX200. So far I've found abotu 90 seconds of error over a little more than 18 hours. I have the scope mounted on an EQ wedge and am running in Eq mode. Smart drive is trained. I took off all the heavy payload and placed the optical axis coincident with the RA axis. Not sure if this is acceptable error or not. It will be interesting to see the delta with between using the Smart Drive and having the Smart drive turned off. I dread re-training the Smart Drive. But if Dennis can do it, I guess I can too <grin>.
You've started a very interesting thread and investigation. Hopefully it will conclude with your scope tracking accurately and an improved understanding of the LX200 for everyone.
On 17 Jun 1995 DK0179@AppleLink.Apple.COM wrote:
> owner-lx200-l@netcom.com
>
> The drive rate ghost strikes again. ! ...
>
>
> There has been suggestions, that drive rate errors reported on this board
> should be due to misinterpretation of natural atmospheric refraction.
>
> Below are the errors in RA (unit : arcminutes) during a 24 hour check.
>
> All data were measured by the quickbasic dos program, published earlier.
> Similar, even more detailed results may be achieved applying Ralphs program.
>
> Please observe, these measurements are independent of misinterpretations,
> mirror shifts, etc...
>
> Previous impressions about the error being time variable are confirmed, I will
> let it run for 3 days, in order to see any repeating pattern.
>
> Please observe, the error is quite large, AVERAGE : 24 arcminutes/day
> correspond to more than 1100 ppm, far above the 50 ppm error claimed in the 16"
> manual.
>
> The error does neither look like a temperature effect, nor like a hour angle
> dependent balancing effect.
>
> What worries me is the fact, that this error is variable, please observe the
> 180 degrees opposite dramatic jumps. On these locations, the drive error
> approximates the errorsize already reported by Bobby Higgins.
>
> I will publish a general review of 3 day data, as soon as it is available.
>
> Does anyone have an idea what maybe wrong ?
>
>
>
> Best greetings ,
>
> Mogens.
>
>
> 11 12 13 14 15 16 17 18 19 20 21 22 23 24 01 02 03 04 05 06 07 08 09 10 11
> ------------------------------------------------------------------------------
> 00.0*
> 01.5 *
> 03.0 *
> 04.5 *
> 06.0 *
> 07.5 *
> 09.0 * *
> 10.5 * *
> 12.0 * *
> 13.5 * * *
> 15.0 * *
> 16.5 * *
> 18.0 * *
> 19.5 * *
> 21.0 * * *
> 22.5 *
> 24.0 *
> ------------------------------------------------------------------------------
> 11 12 13 14 15 16 17 18 19 20 21 22 23 24 01 02 03 04 05 06 07 08 09 10 11
> * *
> * *
> * *
> * *
> Telescope South Telescope North
>
>
>
>
>
> Time RA display
>
>
> 10:55:00 04:00.0#
> 11:08:10 03:59.9#
> 11:53:06 03:59.8#
> 12:50:54 03:59.7#
> 13:52:18 03:59.6#
> 14:39:42 03:59.5#
> 15:32:05 03:59.4#
> 16:12:16 03:59.3#
> 16:45:27 03:59.2#
> 17:06:24 03:59.1#
> 17:13:23 03:59.4#
> 18:00:33 03:59.3#
> 19:38:21 03:59.2#
> 21:03:56 03:59.1#
> 23:34:08 03:59.0#
> 23:44:37 03:58.9#
> 00:52:44 03:58.8#
> 02:07:50 03:58.7#
> 05:40:55 03:58.6#
> 06:08:51 03:59.0#
> 06:12:21 03:58.9#
> 06:29:49 03:58.8#
> 07:09:59 03:58.7#
> 08:16:21 03:58.6#
> 09:41:56 03:58.5#
> 10:48:19 03:58.4#
>
>
>
>