Meade LXD75 SN-10 update.
Posted 15 May 2005 - 01:13 PM
I am posting a follow up to the review I posted about a month ago. After battling the weather, I have had several more opportunities to use this telescope.
The optics continue to impress me favorably: I have resolved both M10 and M12 to my satisfaction. M4 is nothing short of spectacular, with the "bar" well resolved into a line of stars at 143X. I had my "best ever" view of M27 last week, too.
My comments in the review re: finder scope still stand. Even though a post on this website drew my attention to the fact that the objective focuses, I am still far less than favorably impressed. The finder exhibits severe astigmatism and field curvature, and in my hands, virtually unusable. This is an issue that Meade needs to address promptly. A right angle view finder would add to user satisfaction enormously.
I have also had a few more problems with the mount--all balance related. I have to be almost constantly readjusting the tube position at different viwing angles just to maintain balance and avoid gear grinding noises. Meade needs to reconsider mounting this particular scope--the 10"--on a larger and heavier mount, complete with heavier castings and larger polar axis gears. A more powerful drive motor would smooth out the sometimes very jerky slewing in R.A.
Meade LXD 75 SN-10 (UHTC)
TMB 175 f/8
Takahashi TOA 130
Takahashi NJP-160 Temma 2 mount
Schneider 18x80 tripod mounted Flak Binoculars
Posted 16 May 2005 - 02:42 PM
Posted 18 May 2005 - 01:05 PM
Posted 21 May 2005 - 01:18 PM
I had a bad experience with the finder last night. A complete description is in my SN-8 modification post. The thought occurred to me that the finder scope might best be used as an emergency relief device. It will hold about one beer's worth of urine at a hard surfaced site that has no restroom facilities where wet spots on the pavement might be embarrassing. If mailed back to Meade in a full condition, they might get the message as to the value of their LXD75 finder.
Posted 22 May 2005 - 01:07 PM
Posted 22 May 2005 - 02:31 PM
I'm going to check out the spiral search feature tonight and see if that helps at high powers. I located my old Radio Shack turntable level for setting the tripod base level. That should help with the pointing accuracy.
Posted 24 May 2005 - 02:53 PM
Dew shut me down by 3PM. I will have to make a dew shield over the next few days, as there is rain and cloudy nights in the near forecast. A section of 10" lightweight plastic drain pipe and a can of flat black spray paint should work as well as those $40 plastic sheet wraps. Weather should clear for some DSO work by next week as we go into the dark of the moon early in the evening.
I did a bad job of training my drives, as I did it after dark with a low powered eyepiece and I KNOW that I was a bit off and the slew distance isn't much to begin with. Most likely that is my biggest error, as it could have been as much as 10% off. I will be more careful next time, and see if things improve. I hear that subsequent drive training gets things more accurate. I have heard horror stories of drive gears slipping in early LXD55 models, encoder wheel misalignment, and faulty hand controllers. The alignment seemed to get worse as I went from object to object. I obviously did a poor job on polar alignment, as I know that Polaris is not exactly in line with the earth's axis. I assume you have to rotate the mount to the proper point in right ascension before the lighted reticle marks will really get you on target as Polaris apparently wobbles around true north. A lot to learn on just getting the mount aligned and the tracking drives properly trained. Meade SHOULD have sent a DVD with the scope showing everything being properly setup to different levels of accuracy and why it is so, as I can see how those who slept during science and physics classes will pull out a lot of hair during the learning curve.
This is north Texas, and slewing to Antares, the scope pointed to the nearest fireant mound, so I should see the humor in it all, I guess. The scope is laughing at me.
P.S. I noticed this last night, and you should check it out on your SN-10 OTA as well. When the OTA is sitting on its mirror end with the corrector plate up, I can grab the black corrector end mounting ring and cause it to move a little bit in relation to the tube. All four ring retaining screws are VERY tight, so the internal nuts must be tight on the threads and not allowing further tightening. Some sponginess seems to keep the ring popped out all the way, and I have seen no loss of collimation due to any wobble of the mounting ring. This scope may be high value for cost, but it ain't perfection by a long shot. The finder scope again had a wobble in the mount foot, in spite of tightening it last time.
The Celestron Plossls seem to outperform the Meade 26mm Super Plossl in freedom from flare on bright objects. The Celestrons are fully multicoated and Taiwanese while the Super Plossl just says multicoated and is obviously mainland Chinese in origin. Some have slagged that cheap Celestron Plossl kit I bought for $150, but I think everything works quite decently with my SN-8 (except for the 2X barlow), and for a lot less money and more versatility than the Meade accessory kit would have cost. So if anybody asks about a cheap accessory kit for the LXD75 series..............
Lastly, why doesn't Meade send at least a cheap plastic sheetwrap dew shieled with these scopes? You are DEFINITELY going to need one because of the corrector plate and the end cap is so nicely done that you figure Meade would finish the job and help prevent an inevitable problem for the new scope owner.
Posted 24 May 2005 - 04:08 PM
Posted 24 May 2005 - 05:04 PM
Posted 25 May 2005 - 12:01 PM
Last night I made a dew shield from an automobile windshield sunshade I got from Wal-Mart for $5 (I preferred the Dale Earhhardt Jr. model as it had the darkest logo side). It is feather light and I use a very large and stiff plastic ty-warp spreader to make the open end nearly perfectly round. Clear packaging tape sticks like glue to the plastic film. You can use packaging tape to reinforce high wear areas where it fits tightly to the scope. There is NO DROOP WHATSOVER when slewing it around. Double sided tape keeps inner and outer layers firmly together for more stiffness. After blackening the interior, it seems optically OK, and the double wrap of insulation should work much better than those $40 solid sheet plastic Astrozap units. The silver outer layer is a much poorer radiator of heat than the black dew shields. The dew shield folds flat for transport and the ty-wrap pops the end out very round again. I get 18" of extension past the front plate, and the rearview mirror cutout allows the insulation to extend to the rear of the focuser which helps to keep the tube near the corrector plate warmer for longer. IF THIS DOESN'T WORK FOR YOU, then you at least have a spare auto sunshield (which can't be said for a $40 Astrozap). If it does work for you, then you don't need to spend more on a heated dew shield and power supply. It works for me so far. YMMV.
I tied a shoestring around the shield at the proper location, and then taped in in place permanently. It gives the dew shield plenty of stability without resorting to any velcro stickies on the OTA. It should go just behind the front plate or over the groove that runs around the front plate. If the dew shield hangs up on your tripod, it will easily bend away and cause no damage whatsoever. The feather weight means little scope repositioning in the mount. I have another auto sunshade in the closet, and I might try cutting in up to make a couple of wraps to insulate the rest of the OTA before resorting to any type of heater system. "ALL TUBE SAME SAME" seems better than "face hot, butt cold". The insulation will at least reduce greatly any heater energy needed and I will only have to buy the heater strip and not the entire gizmo from Astrozap if I ever need extra heat. I'm going to use rechargeable D cells and stick with the portable battery pack rather than having power cords to trip over in the dark. I hang the pack from the tripod spreader in order to add more mass for stability and plop my eyepiece case directly under the tripod. My military style flashlight with red lens also sits there for more weight and shines straight down on the case.
Meade forgot to put a magnet on the back of the hand controller so you could stick it to one of the legs in a hurry.
Posted 25 May 2005 - 01:32 PM
Posted 26 May 2005 - 09:33 PM
I will probably have to fine tune the axis alignment of the mount. It seems off a bit in relation to the polar scope. At least now I won't be confused on the alignment stars, which is probably my biggest problem right now. The scope goes to the general area, but not anywhere in the field of view of even the 26mm eyepiece. Clouds ended my session early last night before the moon even came up. The star charts weren't there either. I downloaded a good database of the Messier Catalog, Herschel 400 Club List, and RASC's Finest NGC Objects List, and shoved them into plastic sheet protectors and organized in a binder with the star charts. So now I have a good DSO database. I don't need Go To function for planetary and lunar work anyway, or for wideview scanning, so I have been lax on my Go To training. If the skies clear by this weekend, I will try to get into some serious DSO work even if I have to manually aim the scope using the setting circles.
This reminds me of my basic photo training in the 70's. It's actually easier if you start out with a manual camera because it FORCES you to learn the basics of photography and then you learn when auto control can actually help you. Like Meade says, star alignment assumes some knowledge of the night sky. Slewing to the "brightest star" like the manual says causes a blown alignment half the time, and a wrong one the other half.
I read where Herschel just aimed his big scope at a slightly different declination each night and let the night sky stream past him as he observed, and called down to his sister when he saw something interesting and then she logged in the time so they could determine the exact position later. I guess that would be called a "Come To" mount rather than a "Go To". With plenty of beer and barbecue, that could work for me too.
Posted 27 May 2005 - 01:42 PM
Posted 27 May 2005 - 02:35 PM
Did you ever check the OTA front cap of your SN-10 to see if it floated around a bit like my SN-8 does? As long as stars focus to pinpoint images, I'm not going to let it concern me on mine.
Back on the subject of Orthos and Plossls for these Meade SN scopes, I am interested in the Orion Ultrascopic eyepieces that are Japanese made. They have been staying backordered at Orion lately, and cost approximately the same as the new Stratus series at $89-$129. They have state-of-the-art 5- and 7-element designs using high-refractive-index glasses. They are parfocal and fully multi-coated. The cost seems inline with the LXD75 series of scopes. Problem is, the FOV is the same as my Plossls so I guess I might not see a big difference, except maybe a bit of image quality improvement. I would expect them to be better than the Chinese Plossls I have.
The red spot on Jupiter should transit before midnight my time tonight, so I'll see if I can resolve it with the SN-8 since the forecast is partly cloudy and I can see it from my patio. Seeing conditions have been so bad lately, that I don't think that eyepiece quality would have made much difference, assuming that the eyepiece was at least fair in quality to begin with.
Posted 27 May 2005 - 02:57 PM
Posted 03 June 2005 - 03:27 AM
I need to retrain my drives. It still points a bit outside the FOV of my 32mm EP. I get set up too late at night and need to use high power EP's during the day to train my drives. I did find the Ring Nebula last night. It was plenty bright even with a 6mm EP and a 1.5mm exit pupil. I was worried about the 8" aperture for DSO, but it seems fine. I MUST get a dew heater system before too long.
Posted 05 June 2005 - 01:54 PM
The "Ring" is pretty bright. I have observed it in my Tak TOA 130 with no difficulty.
Unfortunately I have been clouded out for almost 2 weeks; my last observing session was good, tho'. I was able to actually resolve a few stars in M9 (globular cluster), both across the face of the cluster and in the corona using a Pentax 7 XW. There are also 2 much fainter (mag 8.9 and ~10)
globulars nearby, which I was able to find/observe. I also bagged Caldwell 57 (mag 9.3) globular cluster.
Posted 07 June 2005 - 09:47 AM
The Auto Star will be close on the first couple of objects, then get progressively worse from there, so something is slipping (tightened the clutch levers, but no change) or the encoder wheels are not being read correctly. The drive tends to overshoot the object. I hear that is a common problem with my mount as the encoder wheels are easily damaged. I do 3-star alignments, and still no improvement. I am carefully retraining the drives today with my high power EP, and checking for any programming glitches. Other than the Auto Star problems, the system is doing good. I certainly DID get some improvement with my last night time drive training session, but Meade says to perform it during the day for greater accuracy, so I will give it another shot before giving them a call. I do no photography at this time, so perfect polar alignment should not be an issue. My problem is probably with the drive training, and I need to study the HPP function in the Auto Star. I finally got the replacement for the missing safety cap for the counterweight shaft. I dread calling Meade for any service, as it can be a half hour wait on the phone these days since they are having problems with all the new gear they are introducing.
I only have a few days of DSO opportunity left before the moon washes me out for a couple of weeks. I will be switching to early morning viewing by the weekend, so maybe the seeing will be steadier. I plan on getting the Telrad finder and doing mainly star hopping instead of the Auto Star routine. The main selling point for me on the mount was the 9-speed controller and spiral search function, which allows me to go searching on my own in an interesting area. Plugging all the object numbers into the Auto Star will probably take longer if you are in the near vicinity already.
I am getting the helical focuser from Orion. That will give me coarse and fine focusing for quick switching between my non-parfocal EP's. I am also getting a Telrad finder. I have found a nice right angle correct image finder with helical focuser from Stellarvue for $99. It allows the EP's to be changed out for different mags, and the price is in keeping with the telescope price. It should allow a little spotting scope activity at the wildlife refuge that I observe from while waiting for darkness to fall, and I will not have to hold star maps upside down to get the map to agree with what I see.
Posted 07 June 2005 - 12:23 PM
Right now I am contemplating another, higher quality scope as my retirement present "from me to me"! The SN-10 AT was an experiment , venturing into the world of CATs. My Dream Scope is either a TMB 203 f/7 or TMB 228 f/7 (which does not even exist as a prototype yet). I may have to switch to a Mak-Newt in the long run.
Posted 08 June 2005 - 09:00 PM
Actually, Rodger, you should try THIS first, and I intend to as soon as I get to a hardware store: Get some teflon tape that is used in oxygen and gas plumbing for sealing the fittings. Wrap it around the threads of your 2" focuser tube until the 1.25" adapter fits snug but not tight and turns smoothly. The teflon glide should feel good and smooth, like satin on silk. There will be no slop in the system after the Crayford is locked down. Just rack slightly down past focus with the Crayford, lock it down snug, and back out the adapter to perfect focus. The thread pitch is finer than those purpose built helicals, and will focuser easier with the ultra short EP's needed with a fast scope. This will need no additional in-focus like the Orion helical needs, and takes up the slop in the threads. This will also work on your 2" EP adapter, and costs almost zilch. People who make helical focusers can send me hate mail for another one of my down and dirty cheapskate upgrades.
Posted 09 June 2005 - 12:10 PM
Posted 04 July 2005 - 11:34 AM
For $47 a person can upgrade to a nice Borg helical focuser if they have at least 40mm of inward travel on the Crayford. You need part #4317 Helical Focuser S and part #7316 adapter to slide into a 1.25" EP holder.
Hutech Corporation at 877-289-2674, plus several USA dealers like OPT and Anacortes. If you have a bit over 50mm inward travel available, then non-rotating focuser part #7315 is possible to use.
I am also considering another OTA for high power use. Something like a 6"-8" MCT or SCT because I want more portability and that's all the mount can handle. The SN-8 does better below 100X with 1.25" EP's, and that's why I got it.
I am considering getting the Tele Vue 2.5X PowerMate for use with the SN-8 on planetary and cluster viewing for now. It is supposed to be corrected down to f/4. However, the 2X Ultima Barlow at $80 is also corrected down to f/4 and is an APO Barlow. I'll call Astronomics and discuss it with them.
Posted 04 July 2005 - 11:38 AM
The non-rotating #7315 focuser is $80.