Re: RA Mesh adjustment for 2104 model Mach 1 GTO


Roland Christen
 

Sounds perfect!

And if he can post the Dec backlash graph, it would further illuminate things.

Rolando

-----Original Message-----
From: W Hilmo <y.groups@...>
To: main@ap-gto.groups.io
Sent: Mon, Oct 11, 2021 5:11 pm
Subject: Re: [ap-gto] RA Mesh adjustment for 2104 model Mach 1 GTO

Hi Nicholas,

I just took a look at the weather for the San Diego area, and it looks like the next 5 or 6 nights will be good for doing this test.

Here is my suggestion:

Set up with either of your refractors.  Configure PHD2 to use your main camera through the refractor and make sure that it is set for single star guiding (the "use multiple stars" checkbox must be unchecked).  Set the exposure time to 1 second.  Point the scope at the star Alshain in the constellation Aquila.  It's about 6 degrees north of the celestial equator and is a very easy to find, naked eye star that is a bit south of Altair.  For that matter, Altair itself is only about 8.5 degrees from the celestial equator, but is so bright that 1 second exposures will probably saturate it.  In a pinch, you could try Altair instead, but I prefer non-saturated stars, so you'd need an even shorter guide exposure.

Once you have Alshain centered in the field of view, click on it in PHD2 and then hold the shift key down on your keyboard and click the "start tracking" icon.  This will force a calibration.  Once the calibration is complete, stop guiding and set MnMo to 20.00 (you will need to set it in two places, one for each axis).  Click the "clear" button on the graph and then click the "start tracking" icon (without holding the shift key down).  This will start tracking and begin building the graph that Roland wants to see.

Let it run for 20 minutes.

I believe that this will get you the information that Roland needs to see.

I hope that this helps,
-Wade (wadeh237 from Cloudy Nights)



On 10/11/21 1:49 PM, Roland Christen via groups.io wrote:
That one is no better. Unfortunately it is cross contaminated. The RA should show the PE and the Dec should show only drift with no PE. It appears that the calibration is off by 45 degrees.

It may not even be calibrated at the celestial equator, so it's not going to be accurate for RA.

Rolando



-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Mon, Oct 11, 2021 3:36 pm
Subject: Re: [ap-gto] RA Mesh adjustment for 2104 model Mach 1 GTO

I found an earlier run that looks better:

image.png
image.png

The previous run was unguided data

There were significant number of failed calibration attempts

Not sure what's going on with the previous graph and so many difficulties with calibration. It may be that you have a cable or connection loose somewhere



On Mon, Oct 11, 2021 at 1:30 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
I'm afraid that is useless data.

Guide graphs ideally should be taken thru the main scope on ONE reasonably bright star at or near the celestial equator, at or near the meridian (either side will do). One star, not multi-star tracking!

What he captured here appears to be a mix of hot pixel tracking along with some periods of actual multi-star tracking.

Rolando

-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Mon, Oct 11, 2021 3:14 pm
Subject: Re: [ap-gto] RA Mesh adjustment for 2104 model Mach 1 GTO

Here's the picture from those logs - unguided output with 2 second exposures, approx 20 minutes total time



image.png

On Mon, Oct 11, 2021 at 12:59 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
Guide logs are great for Geeks that like to wade thru long log files. I'm not one of them.

In order to evaluate the health of your mount I would like to see the following done as I asked before: a simple guide graph screen shot.

1) Take a 15 - 20 minute guide graph with guide exposure set to 1 second on a reasonably right star (forget multi-star guiding, it's not important for this mount health test)
2) for the entirety of the test have guide corrections turned OFF

Easiest way to turn off guide corrections is to set MinMove to 20.0 for both axes. Another way is to go into your guide setup and uncheck the guide corrections box for RA and Dec.

The screen shot should show both the drift of both axes as well as the shape of the RA periodic error for the entire 15 - 20 minute period. It will be a clean image of only the mount with none of the interference of any outside software.

Once I get that screen shot from you I can evaluate the state of the mount, whether the bearings are smooth or not and lots of other things that may or may not need some care or adjustment. Until i see that, we cannot do much here but watch and wait. I have only a few more days here at AP, after which I will be gone on an extended trip and won't be able to advise you until I get back the first week of November.

Rolando

-----Original Message-----
From: nicholas via groups.io <chironik=yahoo.com@groups.io>
To: main@ap-gto.groups.io
Sent: Mon, Oct 11, 2021 2:24 pm
Subject: Re: [ap-gto] RA Mesh adjustment for 2104 model Mach 1 GTO

Hello Mr. Christen.

Firstly I want to express my sincere gratitude for offering to evaluate my Phd2 log data in light of how busy you must already be.   I am not convinced that any issues are not operational efficiency, for example, I likely could improve on my guide-scope/ guide cam structure to make it more solid. On the saddle was a 152mm F8 refractor triplet with a few LBS of imaging related equipment.

Attached is Phd2 log from last night. @ 23:48 I began a recalibration, then I proceeded with the guide assist on after having skewed from the handbox from Park 3 to NGC 7541.
Thank you!

https://openphdguidi...2_logs_Yrrd.zip

--
Roland Christen
Astro-Physics


--
Brian 



Brian Valente

--
Roland Christen
Astro-Physics


--
Brian 



Brian Valente

--
Roland Christen
Astro-Physics
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--
Roland Christen
Astro-Physics

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