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astronomer2002

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About astronomer2002

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    Nebula

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    Maidenhead
  1. Thankyou for all who posted suggestions, they have all been very helpful. As I said initially I have no knowledge of this scope and was working on the assumption there was an issue as my friend, who has had it for many years, indicated it no longer worked. I have finally got it to work properly in alt-az mode. The key was to start with the scope pointing North and to have the single arm on the west side of the mount. My process was: Switch on Pont scope at Polaris (suggested here) Move tube to horizontal with aid of spirit level Set time and date and check location Select 2 star alignment and choose Deneb Drive to Deneb and centre in ep. Press Align Select Capella and drive to it through southern path (ie not going through North) Centre Capella in ep and press align Get the usual 'congratulations' message Tell scope to drive to M37 - Eurika - it does! Tell scope to drive to M57 - once again it does. Tell scope to goto M15 - it's in the ep! Basically nothing wrong with the scope when set up like this. I have not tried the other methods but don't believe there is anything wrong, except the large gear backlash which seems endemic. Thankyou all again Ian B
  2. Thankyou all for the heads up on date and time needed to be entered every time - seems it is a design feature rather than an issue just with this scope. Still not sure if there is a battery somewhere that needs replacing to keep the entered data, or is it that one of the eproms is written to each time you enter anything? I'm used to hidden batteries in handsets or mother boards that die after a few years. I'm running the scope off 12v 5a power supply that I use on several modern mounts, a lot simpler and cheaper than 8 AA batteries. I tried it with rechargeables but it didn't like the ~10v that provided. The manual does not tell me to do anything more than put the tube horizontal for the 2 star align so I guess not orienting it North is going to be the issue. I really hope so as that is a simple 'fix'. Dates/times/lat/long and time zone are all correct though I note the time zone seems to be lost when you turn the scope off as well. I will try the set up procedure again - if we ever get clearish skies! Ian B
  3. Thankyou for the suggestions. I'm sure the date is correct way round as there is no month 18! From the Instruction Manual there appears to be no reference to date and time if yo are doing a 2 star alignment. I would really like to know whether 2 star alignment needs all the date and time elements to be correct and the tube pointed North before it will work. It seems unlikely as it is relatively hard to get to the date, time etc through the menu. I would also have thought the date and time would be accurate after the scope had been turned off for a couple of days rather than simply remembering the last date/time it was on. Not sure if something is broken here. Manual is unclear and there seems to be no battery to keep the clock running, which is another oddity. It states you need the tube pointed North and horizontal plus the correct date and time for the Automatic alignment, which is understandable as it is then going to select alignment stars and slew to them. Has anyone still got one of these original mounts or can remember if the 2 star alignment worked if the date was a couple of days out? I have had, and still have, quite a few mounts each with their own idiosyncrasies, but this one seems either broken or the instructions are wrong I am using this copy of the manual: http://www.company7.com/library/celestron/nexstar_8_manual.pdf Ian B nexstar_8_manual.pdf
  4. This topic has just reminded me of my endless fights with dew on refractors, reflectors and SCT's. Nothing really worked better for me than a long, cheap, black art drawing paper dew shield held on with elastic bands. Tried it out of desperation once when at a school outreach session and it stopped the sct from dewing up. The soft black drawing paper came from their art dept! Worked better than any purchased dew shield! Worst scope for dewing up I have at the moment is a truss RC. the main mirror goes almost as soon as the secondary. If I heat the secondary the main mirror still curtails observing. Open tubes in this country are a liability. Don't imagine a refractor will be immune, I have had issues with these as well, though to be fair they take longer to dew up if they have decent dew shields. Once again the long art paper dewshield worked with them too even if they had long metal dewshields. Ian B
  5. I sympathise with your problem Matt. I have struggled with this for years. I tried Dew shields, multiple bands desiccant in the tube etc. Trouble is the air is so moist in this country at this time of year. The only way I found to hold it off for a while is to thoroughly heat the tube and corrector with a hair dryer about 15 mins before observing. It cools down just in time for visual use and a few mins longer for imaging. Then I have 1/2 an hour to an hour before the corrector dews up again. I have heard some flocking material does a decent job of holding off dewing. I cork lined an SCT I had many years ago, it was a messy and tricky job and to be honest made no noticeable difference to dewing. Ian B
  6. I am trying to help a friend set up his old Nexstar 8 and it's got me beat at the moment. The telescope is an original version from the 1990's and has a hand unit version of 2.12.12.6 I have checked the stored location is in the UK though I believe the 2 star alignment process for alt-az use doesn't use this. The date and time are also correct, though I notice it does not keep date and time up to date. When switched on it displays the date and time of the day it was last used. Maybe this is a clue? I don't know if this is how the scope is supposed to behave. Anyway......... I switch on and go through the 2 star alignment ie set tube horizontal and then centre on 2 stars widely separated. I chose Vega and Capella. It comes back and tells me it's aligned! Easy - so far. Then I tell it to slew to M45, nothing too hard to start with and not far from Capella, and it tells me it's below the horizon and starts to turn the scope upside down! Turn off and start again. This time I choose Capells and Deneb. Congratulates me and tells me it's ready. As my second star was Deneb I suggested it might like to try going to M27. It tells me that is below the horizon and when I overide it the tube starts to go upside down. This age of Nexstar appears to have the OTA permanently fixed in place so cannot be upside down. Also I figure if it was something like that then the alignment would fail. I am now stumped. Can't see how it can calculate that it is aligned after I do the alignment and then not know where it is. Any help would be greatly appreciated. Ian B
  7. Thankyou for offering to scan constellation lists. I have actually been offered one via UKABS and now have it! Ian B
  8. Thankyou for the offer - there's rather a lot of pages though! I have the Cambridge double star atlas but the format of the Sissy Haas will ensure I don't miss any. Bonkers prices on the Internet for an amateurs reference book . I have been hoping to get a copy for nearer the £20 mark It's another item that I suspect many have but never actually use any more. Ian B
  9. Thought I would post an update to this saga. Having tried the 41 Panoptic and ES 40 for some time I conclude I like the Panoptic 5% more than the ES. This sounds pretty arbitrary but I have tried to put a figure on it and there is no area where I can say the ES is better through my eyes and my telescopes. To be honest the ES has a slightly larger field despite having a shorter focal length and the same declared angular field. If it were a question of finance alone I would opt for the ES, but this is astronomy and once you have gleaned a 1% improvement that clinches any decision. I am therefor probably going to sell the ES. Having said all this I find I use the 31mm and 26mm Naglers more often than the big Panoptic. Indeed the old 20mm Nagler still sees many more outings. For those who said for wide ,flat, fields you are using the wrong telescope I can agree that a decent short frac has the right credentials and to that end have added a FLT132 to my burgeoning scope collection (and overloaded mount!) Now I have my widefield eyepieces sorted I am looking at the other end. I have found myself using my old Ortho's on planets even though I have Naglers down to 7mm, since the crispness of Ortho eyepieces surpasses that of any other eyepiece I have ever owned (had a monocentric a long time ago but it went walkabouts before I had a decent enough telescope to appreciate it). After comparing recent acquisitions to my ancient Meade RG ortho's (7mm and 16.8mm) I once again I find myself looking for the best. I don't need higher powers for my long SCT's but for the FLT I need to fill the gap in fl's less than 7mm. I have 1970's volcano top orthos in 6mm and 5mm fl, but they just aren't as crisp as the 7mm RG Meade. I acquired a 10mm BCO, which to be honest does not give the crispness of the Meade RG's followed by a 12.5mm Fujiyama HD-O to fill in the 16.8mm to 7mm gap, but am looking for 4mm, 5mm and 6mm to use with the FLT to get the best out of that scope on planets and doubles. I have been put off the BCO's as they appear no better than my 40+ year old volcano tops. I believe I have sourced a 6mm BGO but also need a 5mm semi-premium ortho at least. I am also trying an old 4mm from the volcano top days to see if that is usable and if so will need the best 4mm Ortho I can source. I find it very odd that there are no mid price range Ortho's out there today with the plethora of short apo's on the market. To get the best out of your 4-6 inch apo on planets there seems to be nothing better than a decent ortho and today they are as rare as hens teeth new and about the same on the s/h market. The BCO's and Kson examples are available, and are cheap, but no better than the ancient volcano tops despite the improvement in coatings there has been in 40 years. I also note the BCO range now stops at 6mm, which seems an odd marketing move. I really hope the weather picks up soon so I can get out there observing as getting my astro fix through buying kit is getting expensive! Ian B
  10. Does anyone have a copy of this 2006 book they would part with? It's been out of print for a while. Since it primarily uses RA and Dec to identify stars it may not get the use of other catalogues that use SAO numbers, making them easier for GoTo scopes, maybe you have a copy just sitting on a shelf? Thankyou for looking Ian B
  11. The focus motor is intended for a Meade scope so I don't know if the bolt holes on the focus mount on the Celestron will line up. See the images in first post to see how it fits over the existing manual focuser. The hand controller has a momentary on-off-on three way action so you can toggle the focuser in either direction without having to lift your thumb from the switch. I have used it and it works well in either hand. The speed of the JMI electric focuser is controlled via a small rotary wheel on the motor itself. This is the way JMI built it. It may sound odd but it is quite easy to use in practice. Ramp it up to full speed to get course focus and then reduce it for fine focusing. Ian B
  12. I am selling a JMI focus motor for Meade SCT's. It has a replacement controller as the original was lost many years ago. Works fine on a LX200. Asking £40 for complete unit and controller plus £5 if you need it posted. ***************** SOLD ******************
  13. I was not aware of this rule. I am trying to help a friend who is suffering health issues. I am selling the items and have them in my possession. If there are issues with them I will deal with those. I hope this is not going to be an issue, it would be sad if SGL forbids helping friends in need. Ian B
  14. For sake of clarity and compliance with the rules of selling, that have just been pointed out to me, I should make it clear I am selling these items . I will pass the proceeds on to my friend, but take responsibility for the transactions and the items being sold. I am selling some astro equipment for a friend who is unable to use them any more. The big items have gone but I am left with some accessories. Here is a list and what we are looking for:- JMI Robofocus for SCT's with controller - £45 Meade Electronic Eyepiece - £20 Off axis Guider for SCT's - £30 ********* Now Sold ********** Telrad with Solar Finder and new base - £25 ********* Now Sold ********** Postage on above will be £5 each but can be amalgamated. Pickup from Maidenhead also fine. All are in working condition and have been tested. The Telrad is unusual in that it has a Solar finder with it. There is a hood to protect your eyes from the sun when using the Solar finder. The Electronic eyepiece runs off a battery and needs a TV/monitor with composite image input or a video camera. It works well when showing a group the Moon or planets. The of-axis guider has the standard T2 thread allowing many CCD cameras to be directly attached or used with an adapter with your digital SLR The JMI Robofocus is designed for Meade's and I believe it will also fit Celestrons. The controller has a 9v internal battery and is operated by a toggle switch. Fits well in teh hand using your thumb to control the motor start/stop and direction. Speed is controlled on the motor itself
  15. 3 months after I acquired the ES68 Argon filled 40mm I was offered a 41 Panoptic and so now have both. Given the lousy seeing conditions we have experienced this year it is unfair to make too strong a claim for these two eyepieces that obviously require the darkest possible sky to perform to their max however I do have some initial observations. The 41 Pan turns out to be less of a problem to use than many on astro sites suggest. I find it quite easy to position my eye in the right place and the shorter eye relief actually makes using the ep more convenient than the ES 40 since the eyecup on that ep is too short to form a good barrier against external light interference. The adjustable eyecup on the 41 Pan scores here. The stars are definitely sharper across the field in the Panoptic and the sky a little darker. I do not find the field stop particularly fuzzy with the Panoptic, which was an issue I worried about. To be honest the slightly out of focus stars at the edge of the field in the ES are more noticeable than any lack of sharpness in the field stop of the Pan. Measuring the true FOV I would have to conclude there is little to choose between them. I got the impression the ES had a very slightly larger TFOV, though this is very hard to quantify. Both eyepieces seem to suffer some vignetting when used with a 2 inch star diagonal. The outer part of the field is definitely darker in both eps. Without the star diagonal the situation improves, but is still just about noticeable. I suspect that if the sky was darker it would be hard to detect. All in all the Pan wins out for me, but not by much. I will wait for darker, clearer skies before making a final decision because both eyepieces show too bright a sky background in the current nighttime conditions. As a result the 31 Nagler continues to be my favorite low power ep. If anyone want's an ES68 40mm in pristine condition in a couple of months I expect I will be passing that one on. Ian B
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