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5haan_A

Help PHD2 is calibrating in only 2 steps

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Hi,

 

I'm sure I must be doing something simple quite wrong, but I can't seem to figure out what the problem is.

The problem is that when running a calibration routine with PHD2 it finishes after completing just 2 steps East, west, north and south. Instead of taking the recommended 12. What this means is that I can't guide at all using PHD2, which is really stopping me from taking long exposures. 

 

To date I have tried reinstalling PHD2, following most of the best practice guide, I have changed the RA side reel rate in EQASCOM regardless of whether I use 0.1 or 0.9 it always does a 2 step calibration and even went as far as reinstalling windows completely. Nothing has worked. 

 

When calibrating I try and keep the DEC to around 20 or below, its hard where I live to get to 0, furthermore I am polar aligning fine using sharpcap so PA is usually rated good or excellent depending on my patience. 

 

Here are some screenshots to show what I have going on in the settings. 

 

1940506754_EqmodAscomSetup.PNG.5c7be0044e74462a7ad75871208548f1.PNG1013899889_PHD2advancedsetup.PNG.0ac7576f8e1ec6291354f50a8326d222.PNG2042048796_Detailedcalibrationparametres.PNG.041e89bbb94fb3a87af9b3dc2a94b2b8.PNG

Also, I have attached some log files from last night. They don't show much but do show that its calibrating in 2 steps. 

Equipment wise:

 

EQ6-Pro mount

ZWO 120 mm guide cam 

Evoguide 50 ED guide scope

 

Thanks,

 

PHD2_GuideLog_2019-10-09_231849.txt

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Have you tried altering the step size by a lot, not a little bit, can't remember which way but try both low and high to see if it alters then refine it to get a dozen or so steps.

Dave

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Hi, like Dave said,

You probably need to reduce Calibration Step, ms value.

Leave EQMOD at guide rate 0.5 (for the start), PHD should pick it up and pre-set default 0.5 value in the "Detailed Calib Parameters" Guide Speed section,

And also, check which EPOCH you use on other Astro software, JNOW or J2000 and set up EQMOD accordingly. You should use the same Epoch on all the software.

Maybe this one also will help https://openphdguiding.org/man-dev/Trouble_shooting.htm

P.S

Now, we all know were your home and astro rig is based... (paint the coords off from EQMOD pic). :)

Edited by RolandKol

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4 hours ago, RolandKol said:

Now, we all know were your home and astro rig is based... (paint the coords off from EQMOD pic)

Wow. Would you believe it but I actually just realised of the back of your comment that I had typo'd the coords wrong into eqascom 😂

 

It might not be causing me to calibrate phd2 with 2 steps, but it certainly wont be helping my situation to have it wrong in there.

 

Best,

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You can see from the Cal results from PHD2 that the N/S moves are along the same axis as RA instead of being at 90 degrees to each other, possibly a cabling problem.

The Cal also shows wildly different Guide rates: Calibration guide speeds: RA = 7.5 a-s/s, Dec = 1.5 a-s/s but this may be a red herring due to the Dec motion being in the wrong direction, so ignore for now while you sort out your cable.

To check the cabling use the PHD2 Manual Guide in the Tools menu.

Set the Guide Pulse Duration to 5000.

Then check each button N S E W moves the guidestar in the correct direction.

The buttons only make one move per press, they're not continuous motion.

Michael


 

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10 minutes ago, michael8554 said:

possibly a cabling problem.

What kind of cabling problem could it be? 

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Had another crack calibrating tonight. Got to something a little bit more acceptable. 

1848936097_Calidata.PNG.e6236f24676287e48aa606be00342eec.PNG

 

This is more what I after isnt it? I'm not familiar with what acceptable calibration data looks like but I'm assuming because I got no warnings and I did more than 2 steps this is better.

To be honest I dont have a smart way of how the above happened. I used my newer laptop, installed all the astro software and it just seemed to work straight out of the blocks. I'm not complaining.

 

Edited by 5haan_A

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7 hours ago, 5haan_A said:

Had another crack calibrating tonight. Got to something a little bit more acceptable. 

This is more what I after isnt it? I'm not familiar with what acceptable calibration data looks like but I'm assuming because I got no warnings and I did more than 2 steps this is better.

To be honest I dont have a smart way of how the above happened. I used my newer laptop, installed all the astro software and it just seemed to work straight out of the blocks. I'm not complaining.

 

For Skywatcher Mount like HEQ5 or NEQ6, - it is good (not perfect).

For something like Mesu200, - not really good at all...

depends what you've got.

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5 hours ago, RolandKol said:

For Skywatcher Mount like HEQ5 or NEQ6, - it is good (not perfect).

For something like Mesu200, - not really good at all...

depends what you've got.

I have an eq6 mount so I'll take that. What are the steps I can take to improve the calibration? 

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In your place, I would not, as the Calibration procedure succeeded, so the next step, - guiding and Imaging.

If you will be happy with the imaging results, - why should you spend any time on adjustments to make some red/blue graph look nice?

The end result is what matters.

:)

P.S.

If you will run into guiding guiding problems, and you probably will, - you will need to improve the Guiding, not the calibration itself :)

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4 minutes ago, RolandKol said:

In your place, I would not, as the Calibration procedure succeeded, so the next step, - guiding and Imaging.

If you will be happy with the imaging results, - why should you spend any time on adjustments to make some red/blue graph look nice?

The end result is what matters.

:)

P.S.

If you will run into guiding guiding problems, and you probably will, - you will need to improve the Guiding, not the calibration itself :)

100% agree with that sentiment. We astronomers can sometimes spend too long looking down rather than looking up.

 

Thanks 

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