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DaveL59

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Posts posted by DaveL59


  1. you might be able to polish the scratches out with something like a car headlight refurb kit, but then a new dome probably works out cheaper and won't result in any optical irregularities. Depends if the marks are in the visual line of sight vs the camera lens position. Defo worth taping over the dome next time, perhaps.

    What are you planning to seal under the dome edge with? I used a nitrile wide flat washer which seemed to work well on my el-cheapo rig and means the dome is easily removable compared to silicone RTV. You do want to avoid capilliary action drawing water in under the edge tho but don't want the clamping force to be so great as to distort/crack the dome rim. Some stainless washers might help spread the load a little?

    As for a lens, I think that's the harder part, what fitment is it, C/CS or M12? 
    I guess lens speed is less of an issue given its an astro camera so can run slow exposure, but a decent F1.4-F2 can be pricey and you'd need to match against the sensor size if you want a full-360 with no clipping of 2 edges. I've seen fuji CS lenses come up but they're in the £90+ region. I guess you'd also need a lens with IRcut filter built in or you'll get some odd colour effects in daylight

    • Thanks 1

  2. the Prinz 660 refractor? Lucky as that's reputed to be a very nice vintage scope.

    The filters would be 2 separate round components, one moon and one sun, that would screw into the bottom of the eyepiece as banjaxed has said. best to bin the sun one or at least seal it in a bag labelled "never use!". Not sure if this scope uses the older 0.96-inch eyepieces, in which case it may be hard to source replacements if they are missing, but IIRC you can mod the focuser to work with 1.25-inch EP's which makes obtaining better EP's a lot easier.


  3. almost sounds like its not coming to focus as you should find it'll snap into focus and be able to make out detail. Did it come with any filters, sometimes there's a ND moon filter which may help reduce the brightness if its overpowering your eye.

    When you had it in focus in daytime, was it a distant object and how far in/out did you have to crank the focuser to achieve? 
    If you were near the end of travel then perhaps there's not enough travel for focus on astro targets with the eyepiece.

    If the focuser doesn't have enough in/out travel then it may not manage with just the eyepiece, was it configured for photography use I wonder? Tho I'd have thought modern scopes would have adequate in-travel for photo use without shifting the mirror so I may be well wide of the mark with that train of thought...


  4. should also add...

    what's the condition of the scope?

    If the mirrors are good and the controls all work fine, a DIY overhaul of the moving bits and some minor tuning may be all it really needs. Cosmetics like paint aren't that important and could always be re-touched/repainted. So long as all the bits are there and undamaged and the mirrors are good then it may serve you well for some time 🙂 


  5. it all depends how much you are into the hobby I guess and what you plan to be observing and budget you're thinking of. 

    I started not so long ago with scopes and went the used route but mainly looked for TAL since they've a good reputation for being solid build and good performers. Been happy with the ones I've collected so far, tho I do have a skywatcher 130 on EQ2 with RA drive that I got for a bargain price too. Things to bear in mind will be that a kit bought new may still need upgrading, better eyepieces and maybe finder. Mount perhaps also. In which case you're adding extra/future costs.

    I'd suggest that adding some better EPs and barlow for the scope you have isn't a bad investment as they're 1.25 inch std type and could then be used on another scope if you do upgrade later. A red dot finder isn't expensive either. If you keep a lookout you might be able to pick up a better tripod and EQ5 mount for reasonable money and can always add RA/dual-axis or even SynScan to that if you wish to later on. Then to upgrade you'd only need an OTA and tube rings and use that mount and accessories you already own.

     


  6. not sure which would fit in what's available new, looks a similar arrangement to my EQ2 the motor gear engages to the large wheel and the motor slots onto the silver bush to the left of the lever, spring adds the tension to keep it engaged. That lever with the part-disc acts as a stand-off for when you want the motor disengaged. So might be a current EQ1/2 motor may work but I'm not qualified to say for sure. Will see if I can get a pic of the EQ2 with motor later if that helps.


  7. looks similar and different to the SW EQ2 that my 130 is mounted on, but has the same sort of arrangement on the RA so you could add an RA motor to aid tracking if you decide to stay with it. I guess you could get an EQ2/3 to make it more stable if it turns out to be too wobbly in use, but since its already bought give it a whirl as-is and see how it performs then decide what's best to do. 

    If it used std 1.25-inch eyepieces then no harm in buying a couple better ones and barlow as you can always use these on other scopes, since most supplied ones aren't all that good anyway. If its the smaller size then they're hard to obtain at a decent quality nowadays tho you can sometimes find the odd S/H one and build a collection over time. I'd agree re the finder tho, a red-dot one would make it a lot easier to use.


  8. also are you starting with the lowest power eyepiece, the one with the larger number on it? and without the barlow lens fitted. Too much magnification will darken the image so always best to start with low power and then work up.

    None of the mirrors came fitted with a protective cover on them to protect them in transit did they? Never bought a scope new hence the question. You should be able to look down the tube and see a nice clear mirror at the bottom and the reflection of the smaller secondary. With no eyepiece fitted and aiming in daylight away from the sun, you should see light down the eyepiece tube which would at least confirm that light is reaching the main mirror and reflecting off the smaller secondary and up to where they eyepiece would sit, assuming they are at least reasonably aligned.


  9. the second link (cloudynights) shows the order the lenses go in if you scroll down just under halfway.

    The double (thicker) in first then the spacer and then the thinner single at the top of the tube. More curved sides facing each other when fitted up into the tube.

    Handy that the prisms are still in place as that'd be more fiddly and they can be easily chipped so looks like hopefully a simple refit task :) 


  10. Hi Clair

    might be worth posting a pic of the eyepiece to give us a clue :) 

    You can hopefully reassemble but if can be a bit fiddly getting the small lenses into the body and staying the right way up en route, worth giving each a clean with lens cleaner and avoid handling with fingers as you add each back in if poss too. 


  11. Hi Louise

    yeah that was the one, at that low output hopefully it'll be fine then :) Must admit I looked at the photos of its build "quality" and toes just curled. You'd expect a better finish in mass produced boards but then at that price... Having said that the rats-nest wiring in some items at much higher prices leaves me speechless too, surprising what can lurk beneath a nice classy fascia that you don't get to find out till something stops working.


  12. yikes, don't like the fact that there's no drillings for mounting posts in the board nor any heatsinks. I guess for the price it is dirt cheap, make sure its in a well insulated enclosure and cables secured with suitable strain relief. You might want to have some ventilation also to assist cooling if running for extended periods, guess you'll know once its up and running and you can carefully check its operating temps.


  13. silly question, but cap on the end of the main tube removed? Just like with a camera, easily forgotten :) 

    Also use the lowest power eyepiece without the barlow - the one with the higher number, usually 25mm or 20mm in the supplied set.

    as above, once you can see something then do align the finder on what you have got centred in the main eyepiece, will make life a lot easier when trying to target points in the night sky.

    • Like 2

  14. yeah so far mine has been fine in all weathers, no misting or frosting as the CCTV module runs quite warm so acts as its own dew heater 🙂

    I have another camera that's in its regular non-outdoor housing with lens that's been running for over a year to monitor the area I put food for the hedgehog, hanging under an old ready-meal tray to keep rain off. I did cover all the case joins and SD slot with dielectric grease and it all still works fine, no frosting or misting up at all.

    For my main el-cheapo cam I've used a different poly dome than the original as it was smoked, as well as to improve weather sealing on the inverted CCTV dome rig with a neoprene seal between the lip and the dome body, so far has worked really well. The smaller cheaper housing looks like a seal has failed and unfortunately that one now has condensation coating the inside and after rain has water sitting in the base of the housing. That one's gonna have to come down altogether I think, might be usable to house the hog-cam perhaps but I don't think I'll be running that housing inverted again.


  15. how well does the housing stand up to being "inverted" with the dome up?

    I DIY'd mine using a ip-CCTV module and adapted a housing to suit and that works reasonably well so far. Another cheaper dome housing hasn't faired so well at resisting water ingress so I'll have to pull it apart and see what can be done, one day...

    The Sony starvis sensors (assuming that's what this one has)  do a reasonable job at picking up the brighter stars even with the fast minimum shutter speed so like you I find its a handy day/night sky view.

    You might be able to polish the dome to improve it, car headlight polishing kits might work for that, but you may also be able to source a replacement clear dome for relatively low $


  16. I'd agree with James on capacity suggestions, for extended running you need to be looking at much more than the smaller packs can deliver.

    For lead batteries they will be heavy and you should avoid car batteries - they are meant to deliver high cranking current in short bursts but not for long slow discharge so will fail quicker. Regular SLA also don't like being run flat, below 50% and you're shortening the life of the battery. Leisure are better for this as they're designed for deep discharge, but again heavy and its best to avoid cycling them too hard. You need to store lead batteries charged and maintained too.

    Lighter weight Lithium cells are around, LiFePo is a good example and you could pitch for 50% AH rating vs the lead battery and get the same runtime, i.e., 10AH is a reasonable swap for a 17AH lead battery. That's because volts will drop off as battery discharges on a lead cell, where Li types will hold up longer but have a sharp drop off as they near discharged levels, the in-built battery management should protect the cells from abuse. Unfortunately these are still quite expensive but potentially will outlast lead batteries 3x which may balance that out. They also don't need to be charge maintained in the way lead batteries do.

     

    Oh and don't forget when totting up the load to also allow for conversion losses, you may need to add 15% or so to the load total. Then also allow for AH capacity "loss" if operating in cold environments, batteries don't like the cold, some more than others.

    • Like 1

  17. so its states a capacity of 40Ah at 3.7v, for 12v that'd be approx 25-32% of the stated capacity so around 10-12Ah effectively.

    Hope that helps. Are you planning to run all this from that one power pack and what runtime would you be hoping for?

    You'll see some losses ramping to 20v but maybe less that using the mains out into a laptop PSU so might be worth testing both ways and see which is better in terms of battery drain. 

     

    • Like 1
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