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Hi, I was using my 20" f/4 Classic Obsession last night and encountered a problem. I was able to perform a two star alignment followed by a successful GOTO from the catalogue, but then I had to keep tapping on the Azimuth (especially) and Altitude buttons in "guide slow" setting on the hand controller to keep the object centered. I am not even sure that without these corrections the mount would have moved at all, but perhaps it was moving but just slower than it should to track the object. I have had some cable snagging issues and wonder if the power cable has become damaged or connections affected over time by this. Last night when I was setting up and moving the mount around while finding the alignment stars the set up bleeped and restarted without warning. The jog buttons work ok in all directions and I get the three beeps and red flashing light on "DSC", green light on "slew" and yellow light on "HC" on the ServoCat when I power it and the AN up, which is expected. A GOTO on a second object was successful, but again tracking seemed to be poor or non-existant. Does anyone have any suggestions as to what might be going wrong, please? Regards and thanks in advance,

First of all, for those wondering what EAA is, it is kind of a step between observing and astrophotography. In EAA, images are viewed and stacked live with darks and flats (if used) also added live to each image using software optimized for EAA such as Sharpcap Pro. Also the total length of the final stack is usually less than 60 minutes. The 60 minutes is kind of an unwritten rule and one I never come close to breaking, as I stack long enough to see interesting structures or features and then move on to another target (kind of like visual astronomy) I am not after creating a magazine quality image, instead I am interested in seeing challenging things impossible, or next to impossible to see visually (such as the "Twin Quasar" in Ursa Major or other gravitationally lensed objects). This is in contrast to astrophotography, where many images are taken usually over a much longer period of time (sometimes even over several days), then calibrated, stacked and processed later with a goal of a pleasing image. I am not disparaging astrophotography, I have done some of it myself with other instruments and it has its place, for me, though with very limited time to enjoy my hobby, I want to maximize my time toward satisfying my curiosity. Ok, enough with EAA theory and on to problems I have faced that almost made me give up. The most frustrating of them all was poor tracking which results in stars that are double or star trails or smearing in general. While again, I am not after perfection, at some point it becomes too distracting or even impossible to tease out some structure of faint objects. I started doing much more EAA with my 18" Astrosystems Telekit in 2020 and I had great results pretty quickly after watching others use Sharpcap during live-streaming events or recorded on youtube. Also there was lots of help on Cloudy Nights. However, most of the EAA's on cloudy nights now are using refractors, SCTs or Newtonians on equatorial mounts so some of my learning had to be through trial and error. None of my issues early on seemed to be related to tracking. In fact I had some excellent images of some cool objects pretty early on in this adventure. It seemed like after tinkering with my dob trying to make modifications, such as shortening the truss tubes, adding more gadgets to the upper cage (like adding an electronic focuser to my feather touch, power box, etc...) that I started noticing problems with my tracking. My initial thought was that I need to do an autocal to get more precise gear values now that I made so many changes. While that did seem to help for a time, the problem was back and kept getting worse. So worse that even a 1 sec exposure was showing streaks. This week, here in west-central Virginia, we finally had a spell of clear and smoke-free skies and no moon. I got my scope out on Monday and Tues and set out to do some EAA under these fine skies. I noticed that while watching the live view of the camera, that objects drifted significantly almost immediately after they were centered in the field of view. During "Livestacking", Sharpcap can still stack and keep the image centered pretty well with its stacking algorithm, however everything had short streaks. It seemed like the streaks were worse for objects in the east. That got me thinking about backlash for the first time since doing EAA. While my backlash was never perfect, it had always been decent for visual observing with an eyepiece. For any kind of imaging though, the take up of lash would obviously be VERY noticeable in an image, even if minor. So yesterday evening I cracked open the "Backlash Optimization Procedure" PDF. I almost felt like I was breaking open our emergency procedures manual for aircraft emergencies at this point from my old military days and felt confident that I was on to something. I spent over 1 hour gradually increasing the backlash setting numbers for both ALT and AZ and used a high power eyepiece each time to try to notice the absolute immediate moment the scope started to move and the star visibly moving in the field when pressing the button. After zeroing in on a value of 2 arcminutes for AZ and 3 arcminutes for ALT and saving those to the servocat from the Servocat Sky software, I was finally able to do sub-exposures of up to 10 seconds. I managed to do a live stack of NGC 7129 for over 8 minutes with 10 sec exposures. This is something I had never been able to do before. The best I had done previously was 8seconds and that was when I first started. After the problem worsened I had only been able to use 4 sec exposures and finally at the beginning of this week nothing worked. I am so happy and believe I can probably even take longer exposures up to a point due to frame rotation since we are doing Alt-Az imaging versus equatorial. Anyway here is that image last night of NGC 7129, a nice 11.5 magnitude reflection nebula in Cepheus. Also a few planetary nebula images also captured last night. The last image has some fuzzy stars because after I added I switched out a filter, I didn't get my focus perfect.

This is a follow-up to one of my previous threads: /g/ServoCAT/topic/easytrack/106350847 - specifically this message: /g/ServoCAT/message/7003 As the subject line describes - the the ALT DOWN button on the hand controller no longer slews the scope after the first star align. This is a 12 year old GEN3 system that worked as expected until recently This particular failure on alignment first appeared repeatedly during a public observing session back in May. I then set up the scope in the garage and was able to reliably reproduce the failure, post my observation in the above thread, and then it just stopped failing The scope has been sitting for about a month and I finally took another look at it today. Probably at least a half dozen continuous failures. Here's the scenario: - positing scope vertically, facing north - power on, wait for three beeps from AN - SC Slew LED is solid green, HC LED is solid yellow, DSC is rapidly flashing red - MODE FIX ALT REF, ALT REF = 90, AUTO ADJUST OFF, ENTER - MODE ENCODER - Slew scope to approx ALT, AZ of a star (Castor in this case) - MODE ALIGN STAR, CASTOR - Press the hand controller GOTO button to confirm the first star - SC Slew LED is solid green, HC LED is solid yellow, DSC LED is rapidly flashing red - Press the hand controller ALT DOWN button, DSC LED goes off and stays off (the other two LEDs stay on), no movement down in ALT can be achieved - If I slew either direction in AZ, the DSC LED stays off. - If I slew up in ALT, the DSC LED starts to flash rapidly again - If I now try to slew down in ALT, the DSC LED goes out (still able to slew either way in AZ), pressing ALT UP and the DSC LED starts flashing. Three times - same behavior. So I'm thinking to myself, what if I press ENTER on the Argo instead of the hand controller GOTO to confirm the first star? Wow - the DSC LED keeps blinking rapidly and I can slew in all four directions. Reset and tried that again, works. Reset and try the GOTO button, works. Reset and try the GOTO button, works. Very odd. SC firmware is 70A. I have an 18" with the same SC and AN configuration and I tried the HC from that scope and it made no difference when it was failing. I'm going to go do something else for a while and then see how this behaves. :)

Hi all, I retrofitted my classic 18’’ Obsession with a ServoCAT in 2020. I do seem to have a problem with the guiding (but I’m not 100% sure). When I go to an object using my Nexus DSC Pro, I can see that the ServoCat is doing a great job and the numbers on the ServoCAT go down to 0.0, 0.0. However, the object does not stay at 0.0, 0.0, but start to drift (a bit). The numbers on the Nexus will typically go to 0.10 – 0.20. Occasionally the numbers do get better, as the number jumps to 0.05, 0.05 again. Typically, the jumps are in the range of 0.10. Should the numbers just stay at 0.0, 0.0? What is the possible cause for this? Is it because the telescope is not totally level in the garden (in the grass)? Is there a setting on the Nexus or the ServoCAT I need to change? Did I make a mistake while installing the ServoCAT Or is this normal and expected behavior? Thanks a lot for looking into my question, Wim -- Wim De Meester DeepskyLog – Log your visual astronomical observations DeepskyWim – Astronomy and Solar Eclipse Blog WimEnSara – Travel blog Polarsteps – Follow our trips

Dear all, I create a specific thread for observing satelittes by copying / pasting some exchange that was done in /g/ServoCAT/topic/autocal_cable_length/106277132 My initial message : After having updated servocat to version 7 and ArgoNavis to version 3.04. I have for the first time succesfully observed ISS with AN/servocat . Ssssooooo happy ! It was done with my 36" F3.5, with Ethos 21 => magnification x173,FOV 34' I have made some optimisation of the gear ratio but the follow up of ISS is average : I had to push the guide fast right button in continue when ISS was higher speed. I think my gear ratios could be impoved (see above message) and Gary provided support on this. Gary answer : TIME is the very most important criterion. It has to be precise to the second. Alignment I believe is the next critical item. Gary Kopff from WCI can respond to this... the track of any object is going to be an approximate one with the error being directly related to issues of alignment. Mount error - i.e. the mount (the scope) is not made to a very high precision (in most ServoCAT systems it is a WOODEN telescope meant for visual use). So issues with bearing placement side to side forward/backward up/dwn... will come into play. Hold on - I just re-read your note - you didn't REALLY 'see' the ISS ... in a 36" DOB!? Is there is a translation issue there? When I was working on the ServoCAT side of designing this - with my 12" out in the backyard - I knew that doing any type of fast-ish tracking for Earth orbit objects would be limited by the size of the scope and ESPECIALLY if there is a ladder involved... I can't imagine trying to follow with a ladder. I know I did a bunch of booster rocket tracking - and it was moving pretty darn fast. (and it is SO COOL to see this happening - one of the first times this was working I was looking and thought - "its not working, the stars are flying by in the view" ... then I looked again and BINGO - the object I was looking for, however, was DEAD CENTER STATIONARY in the filed. It was a weird sensation). My answer to Gary : Hi gary, No translation issue, it is with a 36" dob. Enclosed a picture. Yes, looking the star "flying" was amazing ! and you see ISS enlarging little by little, see the solar panels as it comes closer then reducing size. All this was great. For accurate time, I did the calibration of the internal clock of AN as indicated in manual using (NTP protocol), so I think it's OK Regarding the ladder issue : in fact my 36" is e Fullum folded scope so it don't need tall ladder. I would say I don't use anything until maybe 40-50° . At zenith 2 steps is enough for me (I'm not tall 1.73), 3 steps for small people, so I have only a 3 step ladder. When I watched ISS it was not a problem in first low alt passage. More an issue at 2nd passage nearby zenith but the ladder was manageable. The main problem I have is certainly the pointing precision not enough on the 36". The pointing precision is not optimal and objects are classically not in the fov. 1 or 2° away. Since few observation, I start to use more and more the wonderful TPAS of AN. But so far I limited to maximum 30 stars => the parameters are not accurate enough yet, and I hope I don't have a non persistent error. This Is 1 of my goal in the next month or let's say automn goal to improve TPAS. When I followed ISS, I had already calculate 2 parameters of TPAS so the pointing was better than usual but anyway, the ISS was just outside of fov. I could easily recentered it but it means the pointing was still not perfect. I had to continuously push the az "CW" button in guide fast mode to keep ISS in the fov. The azimuth following was nearly perfect.