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Equipment Discussions >> Mounts

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Griffin!
sage


Reged: 09/12/10

Re: LX80 RA tracking new [Re: Hilmi]
      #5306287 - 07/07/12 02:28 AM

I don't recall tmohr36 having this issue, and haven't seen it mentioned in any of the early reviews (unles I missed something).

Would be interesting to hear from some of the users who have been using the mount for a while to see if they had any drift problems.

Edited by Griffin! (07/07/12 02:28 AM)


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Starhawk
Space Ranger
*****

Reged: 09/16/08

Loc: Tucson, Arizona
Re: LX80 RA tracking new [Re: Griffin!]
      #5306301 - 07/07/12 03:02 AM

This is the first time anyone tried to run it in equatorial mode, yet. Everyone else has been running in alt/az

This seems to indicate 2 out of 2 new Meade mounts shipped without a checkout of what was being delivered.

-Rich

Edited by Starhawk (07/07/12 03:06 AM)


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TALK2KEV
sage


Reged: 03/08/06

Loc: Oklahoma
Re: LX80 RA tracking new [Re: Starhawk]
      #5306611 - 07/07/12 11:37 AM

Andrew

my HBX is in Route to Meade but your test is very interesting.

David has a new HBX and if all goes well we get more information. I hope his works well.


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TALK2KEV
sage


Reged: 03/08/06

Loc: Oklahoma
Re: LX80 RA tracking new [Re: TALK2KEV]
      #5306646 - 07/07/12 12:03 PM

David
I was reading over all the post and I have a Question about the strange slewing that you experienced. What was your power source? We started using the 8 on board AA's battery pack and quickly changed to a car battery ie thinking that tracking was slow and not sure if the battery pack was up to the test we changed to what we use in the field. I think if we was doing a one hour outreach astronomy event for a school the on board pack would be fine. But even with the Car battery it was still not tracking right. voltage on car bat was 12.5


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brokenwave
sage


Reged: 05/10/11

Loc: Scottsdale, AZ
Re: LX80 RA tracking new [Re: Wigleydh]
      #5306778 - 07/07/12 01:30 PM

My LX80 was one of the first shipped and has LX80 listed in both AZ/Alt and Polar modes. Same firmware listed earlier.
I haven't tried it in EQ mode yet.
October time frame when it cools off here in AZ.


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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking new [Re: brokenwave]
      #5307116 - 07/07/12 05:33 PM Attachment (53 downloads)

OK.... Test Results as promised.
I work in the world of Alt/Az, but can use Polar as well, so I decided to do the test in BOTH Polar AND Alt/Az to see if the problem (if there is one) shows up in one or both or none.

The test perform a "fake" alignment, simply accepting slews as correct. I did the Polar one first. During each test, I would link TheSkyX to the mount, with TheSkyX synced to the mount for time/date. Thus, I was able to also "watch" for drift, if present.

Wow !! Was it ever present (in Polar). I had to restart the procedure a couple of times, because the target was drifting right out of the FOV indicators, and i was sure something must be wrong. Nope !! That is what is happening.

The original posters said they thought the drift was large. I forget their actual statement. Andrew reported a large drift also. As you can see from the results, you would not want to do any imaging here..... actually, i don't think i would want to do any visual with that much drift.

I was very concerned. I re-configured for Alt/AZ and started the testing. To my amazement, little-to-no drift was showing up. As shown, my starting variance from calculated at the start is about the same as my ending variance.

Man.... am i glad i work in Alt/AZ !!!

Not sure what the problem is in Polar, but IMHO, that is not acceptable. So..... where to from here.

Andrew.... is this something that is correctable in the "settings" ?? Or does Meade need to do a patch ?? What are your thoughts please.

As i am seeing it, it appears that the hardware is working correctly. The RA (AZ) function should be the same in either configuration -- Right ?? And it appears to be working fine in Alt/AZ.


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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking new [Re: dmdouglass]
      #5307122 - 07/07/12 05:37 PM

If Andrew or any of our readers can check my math, I "think" i did it right. The variances were calculated by hand, not by the spreadsheet. If there are any errors in calculating the variances, my apologies.

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OzAndrewJ
scholastic sledgehammer
*****

Reged: 11/30/10

Re: LX80 RA tracking new [Re: dmdouglass]
      #5307234 - 07/07/12 07:55 PM

Gday David

Quote:

OK.... Test Results as promised.




Excellent, but not expected.

Quote:

During each test, I would link TheSkyX to the mount, with TheSkyX synced to the mount for time/date. Thus, I was able to also "watch" for drift, if present.




I would have preferred you hadnt done that for starters.
There are bugs in the serial setting of date,
and i also dont know if the SkyX polling for data may affect the results.
The only thing to watch, to determine whats happening, is the RA display on the Hbx.
If you are tracking correctly ( in altaz or Polar ) this will hold steady.

Quote:

Wow !! Was it ever present (in Polar). I had to restart the procedure a couple of times, because the target was drifting right out of the FOV indicators, and i was sure something must be wrong. Nope !! That is what is happening.





And its not what i see with my LX90 cards????

Quote:

The original posters said they thought the drift was large. I forget their actual statement. Andrew reported a large drift also.




My drift was nothing like this, and mine went the other way???

Ie when i did my tests, i got a "speed up" and by a small amount.
Ie my RA went from 13:25.1 down to 13:24.4 over about 1 hour
ie 0.7 RA mins ( which lines up with what i see in code )

Your results show your RA went from 13:25.8 up to 13:43.0 in one hour
ie 17.2 RA mins ( so nearly 25x faster than mine )

Quote:

Andrew.... is this something that is correctable in the "settings" ??




Based on your numbers, i no longer ( think I ) understand whats going on.
Either way, i know of no setting that could do this, other than PEC.
( and if that was the case, i should have seen it )
The original bug i see re the 1.155% increase is a Meade only fix
( until i can patch it ), but i am utterly confused as to whats really happening.

Quote:

As i am seeing it, it appears that the hardware is working correctly.



The 360 deg spin test i mentioned earlier will confirm the ratios/mechanicals.

Andrew


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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking new [Re: OzAndrewJ]
      #5307300 - 07/07/12 08:32 PM

I am going to do some visual tests this evening. I have it set up with two OTA's now (which will be my normal mode).

Tomorrow morning, i will re-configure, and re-run the tests to see if it duplicates. No settings were changed other than the "Telescope Model" (i.e. Alt/AZ vs Polar). Since you mentioned it, i will not connect TheSkyX to the mount during the tests. Will post back tomorrow.


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OzAndrewJ
scholastic sledgehammer
*****

Reged: 11/30/10

Re: LX80 RA tracking [Re: dmdouglass]
      #5307630 - 07/08/12 01:11 AM

Gday David

I still cant understand whats going on,
but if you do rerun the tests and the drift is the same rate,
can you pls confirm what settings your handbox shows for
a) Tracking rate ( what shows under custom )
b) Targets ( ie Astro/Terr )

Looking at your numbers, you are running at approx 70% of sidereal.
( Ie you lost 17.2 RA mins in one hour so did 42.8 vs expected 60 )
This is too neat a number, as the std "guide rate" for the scope is 70%.
Ie normally in polar, the scope tracks in RA at 15arcsec/sec
The guide rate then applies +/-10.5 arcsec/sec based on key pressed.

Its almost as if the scope is tracking at 0 + "Guide rate"
Ie with no underlying "Tracking Rate".
( Thats just a wild guess based on the neat fit of the numbers,
but i cant see why it doesnt happen to my test bench???? )
Need other owners to confirm the one hour test
to see if they all get the same slowdown you do.

Andrew


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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking [Re: OzAndrewJ]
      #5307654 - 07/08/12 01:39 AM Attachment (48 downloads)

Test Run #2 for Alt/AZ –

Well, I was set up anyway, and this time for real (no fake alignment). The configuration was Alt/AZ with two (2) OTA’s. I purchased the LX80-SC6 combination, and already had a Meade 80mm ED-APO. The mount was balanced for both axis, and properly aligned. This was after adjusting the spotter scope to align with the SC, and the 80mm to align with SC. Alignment went very smooth. I pointed the mount to SPICA, and had it dead center on all three eyepieces. Took the readings, and let it sit for an hour. No computer hookup.

At the end of an hour, SPICA was still well centered in all three eye pieces. I would like to add here that I am really impressed with this mount (in Alt/AZ). I purchased it as our “travel” mount, and am very satisfied at this time. As I have said, 95% or more of my usage will be in Alt/AZ. I image all of my observations. Depending on image framing, I use one of the OTA’s for imaging, and the other for guiding. And YES, you can guide with this set-up. I use a Meade DSI-2 Pro for guiding, and Meade ENVISAGE software for guiding. The Computer (and guiding) feed is through the Audiostar serial port.

For Kevin and Dennis, I did re-read the Ratios. (Note: This is for Alt/AZ Only) They were:
Alt/Dec Ratio - 02.75075
AZ/RA Ratio + 02.75075

I will re-configure the mount for polar in the morning, and do a “fake alignment”, and re-run the test.
Results we be posted late tomorrow morning.


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TALK2KEV
sage


Reged: 03/08/06

Loc: Oklahoma
Re: LX80 RA tracking [Re: dmdouglass]
      #5307926 - 07/08/12 09:22 AM

David
Glad everything went well with new HBX. If we can get our drift down to that It will guide great. Looking forward to seeing test results from Polar set up.

Clear Skies


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Wigleydh
member


Reged: 10/26/07

Re: LX80 RA tracking [Re: TALK2KEV]
      #5308167 - 07/08/12 12:09 PM

Andrew your mentioning tracking at guide rate without any underlying tracking rate (as a guess) does make sense compared with what I saw the night I was there with Kevin, even though it didn't show in your test with your LX90.

We didn't actually measure anything that first night. As I decribed, the star was drifting in the field of view every two second exposure with the DSI pro. The drift was so large that I first thought of the targets. I verified the targets were astronomical and should be tracking. I turned off any tracking by setting the targets to terrestrial and the amount of drift with each two second frame increased. I then turned the targets back to astronomical and also verified the tracking rate set to sidereal. The drift went back to the same amount of drift each frame, so we were tracking with the targets set to astronomical but just not at the correct rate. What you mentioned may not be what is happening but that is the best match so far to what I saw on the screen (I haven't thought of anything that comes that close to explaining the amounts of drift I saw). With no actual measurement at that time, the amount of movement change I saw with the tracking on, off, and back on again could have been close to what you were talking about.

It will be interesting to see if David's retest repeats the result.


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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking [Re: Wigleydh]
      #5308434 - 07/08/12 03:12 PM Attachment (34 downloads)

Test Run #2 – Polar Alignment

The setup is the single OTA (SC-6) in Polar configuration. The mount is balanced, and properly aligned for Polar Home (but the alignment is fake as it is being done in the kitchen !!). Pre-test readings as requested, as follows:

Tracking Rate = Custom (??)
Custom = -1
Now a question… there are 3 tracking rates. These are Custom, Lunar, and Sidereal. I am wondering why it is set to Custom (I did not change it…). I would have expected to find Sidereal.

Target: Astronomical
I am aware of this “trap”… I have to go through the same thing with my ETX-90 every time. You forget to check it, and after alignment, your target just slowly drifts out of the FOV…. I have learned that this is the first thing to check before alignment. Well, now the 2nd for the LX80… first would be for the correct configuration (Al/AZ vs Polar).

For Dennis and Kevin..
Alt/Dec Ratio +02.75075
Az/RA Radio +02.75075

Another interesting observation. I did the default alignment (2 star). I simply accepted the slew with no adjustment. The Audiostar reported (17 Up) (11 Left). I would have expected a 0/0 report based on no adjustments. That does not enter into play here, except to explain why calculated is not equal to readings (I think…). But it is an interesting question, at least to me.

Well, the test results produce more questions than answers. I was curious about the difference between the “Custom” vs “Sidereal” Tracking rate, and decided to run the test yet again, this time in Sidereal. Interestingly, the results for “Custom” and “Sidereal” are pretty much the same, but both are different from the first test… I cannot explain why. No setting were adjusted, other than those stated here.

I sure am glad I operate in Alt/AZ….


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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking [Re: dmdouglass]
      #5308471 - 07/08/12 03:34 PM

I have been thinking some more. When the first test was done, the mount was connected to the computer, running TheSkyX. I was "watching" the drift...

Andrew commented about some kind of possible "bug" in that configuration. Could that be a part of this ?? I am interested in this "bug", and i normally operate with the computer attached. In the "for what its worth" department, the first Alt/AZ test was also done with the computer attached, and running TheSkyX. The second Alt/AZ test (last night), and the two Polar tests (today) did NOT have a computer connection.

Interesting situation. Interesting questions. I will try and be available for any other "tests" if needed.


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OzAndrewJ
scholastic sledgehammer
*****

Reged: 11/30/10

Re: LX80 RA tracking [Re: dmdouglass]
      #5308643 - 07/08/12 05:12 PM

Gday David
Quote:

I have been thinking some more. When the first test was done, the mount was connected to the computer, running TheSkyX. I was "watching" the drift...

Andrew commented about some kind of possible "bug" in that configuration. Could that be a part of this ??




Not based on your second set of tests.

I have no answer to drift at that rate at present,
esp since i cant replicate it.
My next suspicion has to be the motorcards programming
but if thats the case, i dont understand why AltAz works.
I dont see any new commands yet, but i havent looked everywhere.
But then again, your numbers now show a drift of 50%
which is the guide rate asserted by the APM909 type moves.
Ie you are tracking at normal sidereal - 50% now.
Im wondering if they have added something extra related
to how the APM909 code works?????
but again, i should see that on my testbench.
We need others to independently cross reference the tests.

As to the 17up 11 left etc results from 2 star aligning,
the system gets rounding errors etc when doing the calcs
as the hbx only has limited computing horsepower,
esp when doing sine/cosine/tan calcs.
I never believe those numbers

Lastly, there is no need to report Alt/Az stuff here,
just RA/DEC deltas will suffice.

Second lastly, grasping at straws here,
can you set the scope to be a polar LX90 as mentioned earlier.
Swap the sign of the Az ratio and then repeat the test.

Andrew


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rmollise
Postmaster
*****

Reged: 07/06/07

Re: LX80 RA tracking [Re: OzAndrewJ]
      #5308682 - 07/08/12 05:43 PM

Also, perform your test outside on a real star after a polar alignment. Doing a fake polar align and fake go-to align and then watching what a planetarium program does is no kind of test.

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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking [Re: rmollise]
      #5308751 - 07/08/12 06:22 PM

Greetings Uncle Rod...

If you read my posts, that is what i did last night in the Alt Az test. Loved the results !

However, when you remove the element of "Watching", then the test is valid, considering we are simply reading the Audidostar handset. We already know (positively) that the drift is real... observation (real) and planetarium. So, this is a "numbers" game... trying to figure out what it is doing.... which is "something" wrong.

If we can get some numbers that look realistic, then i will set it up and do a "real" alignment and "watch" the star... (as i did in Alt/AZ).


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dmdouglass
professor emeritus


Reged: 12/23/07

Loc: Tempe, AZ
Re: LX80 RA tracking [Re: dmdouglass]
      #5308758 - 07/08/12 06:27 PM

Greetings Andrew...

First.... I must tell you that I chuckle everytime I read one of your posts. I love the Gday.....

OK, yes, i will do that. Recall that Meade was trying to get me to use the LXD mount selection (before we upgraded the firmware). I am going to try that also. In fact, that test is currently running. And yes, had to change the (-) to a (+) there too.

Results of the LXD will be available in about an hour. I will post them as soon as available. Then i will re-configure as an LX-90 and do that one.


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rmollise
Postmaster
*****

Reged: 07/06/07

Re: LX80 RA tracking [Re: dmdouglass]
      #5308820 - 07/08/12 07:09 PM

Quote:

Greetings Uncle Rod...

If you read my posts, that is what i did last night in the Alt Az test. Loved the results !

However, when you remove the element of "Watching", then the test is valid, considering we are simply reading the Audidostar handset. We already know (positively) that the drift is real... observation (real) and planetarium. So, this is a "numbers" game... trying to figure out what it is doing.... which is "something" wrong.

If we can get some numbers that look realistic, then i will set it up and do a "real" alignment and "watch" the star... (as i did in Alt/AZ).




Well, yeah, but alt-az ain't the problem is it?


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