NGC 1502

Indeed, with most reflectors that’s true. Not so however with AstroSystems Newtonians. The whole primary cell with mirror attached to the tube with tiny precision screws. It was a simple job to remove, clean the mirror and reattach with collimation unaffected. Tape could be applied around the edge of the mirror and cell so the felt between mirror and cell did not get wet. Simple, effective, brilliant 👍 ……..sadly they don’t make them like that now! Ed.

AstroSystems of Luton got close to this. The primary was glued to thin felt, the felt was glued to a plate that was part of the mirror cell. This did not stress the glass because the felt effectively allowed expansion and contraction of the glass and the cell in different amounts without affecting the other. Simple and brilliant idea! And no mirror clips protruding onto the optical surface. The secondary was siliconed to its mount. Some versions had a full tube diameter support, some had a shorter single vane stalk. Whilst these used thicker metal than usual, once set up they did not shift. They were a bit of a faff to adjust but you only needed to do it once! I once owned an AstroSystems 8.5” f5 Newtonian on an alt-az pillar mount. It was brilliant. And then I STUPIDLY SOLD IT!! If anyone has one, I urge you to be TOTALLY STUPID AND SELL IT TO ME😁 Ed.

Please update when you can, will watch with interest👍

Over many years I’ve made several Dob mounts and modified others. I think experimenting is key because it’s hard to predict how well it will work in practice, especially (as mentioned) at high power. There’s so many factors involved and not just in the choice of materials. I once made a Dob mount for a Skywatcher 10” Newtonian tube assembly bought secondhand. It was ok at low power but iffy at over 100x. After lots of frustrating DIY eventually the problem was revealed. The plywood base of the mount was not completely flat. As it turned on the ground board at times it was ok but at other times it was not, like trying to push something uphill or downhill. Let me explain further “pushing uphill” :- As the mount is rotated you are also trying to lift the rocker box and tube assembly a tiny bit higher from the ground. At other times the opposite occurs. Stiction will vary greatly from no stiction to obvious and frustrating stiction. I’m hoping the above makes sense. Although the construction of a Dob mount looks simple in design don’t allow that to make you casual. Make everything exactly square and flat, rigid as possible. Make it less of a hassle to take apart if necessary by not using glue in the joints, just screws. The “stucco embossed aluminium sheet” certainly looks the part- and as it works so well rejoice👍 Ed.

The Skywatcher ED80 cell easily unscrews as a unit. As mentioned, when reattaching be careful not to cross thread. Removing and reattaching the cell as a unit won’t affect collimation. With the cell removed this gives access to clean the back of the inner lens element. If the problem is between the lens elements it’s a very different situation. Perhaps consider contacting a specialist repairer like the well known Es Reid. If you’re feeling brave you could DIY. An adjustable lens spanner to engage the holes on the front retaining ring would be a good idea. Note the orientation between the 2 elements plus the orientation of them with respect to the cell. Note any spacers. Pencil marks will help. Go carefully and methodically and don’t rush. Finally please understand you can easily mess up. If it were me I’d consider using it as is, or if you can’t live with that contact a specialist as previously mentioned. Hoping you sort it👍

I definitely would not stress about this. An old saying in our hobby is repeated below- “The best scope is the one that gets used” In your situation portability is king. Something larger would likely be a chore and would show you nothing at all if it were too much hassle to use. Enjoy the views😊

Welcome to SGL, you’ve come to the right place, lots of folk here ready to help😊 A good start would be to do as suggested by Louis D in post #2 The various ETX scopes were all “go to” technology. That is once correctly set up, use the handset to let the built in motors find your desired object. Once found the scope should follow the object to compensate for earth’s rotation. Sometimes it’s not quite that simple, but that’s the intention if everything is correctly set up and working as it should! From the pic I can’t see the handset, do you have that? It’s an oblong shape with lots of buttons. What’s the tripod on the left? Doesn’t look like the regular ETX metal tripod. A good start would be to open the battery compartment. Hopefully the batteries previously used have not leaked. Replace with good quality batteries. Cheap batteries are a bad idea, and keep at least one spare set. Please come back with that photo when you can😊

Indeed it’s possible to lose the lower areas of sky in the way you describe. However depending on the surrounding houses etc it can work to your advantage. For me if my scope is lower then my fences hides lights from nearby houses. Several years back when Jupiter and Saturn were very low in the south then I used to put my Dob on a raised brick built flower bed to access those planets…… When I had an 8” Dob then on rare occasions I lifted that onto my workmate to access the lower sky. A bit wobbly but a wobbly view was better than no view! Necessity is the mother of invention 😊

Agree with above. There’s no reason at all that a Dob mount should be unstable, it will have 3 very short feet, so if the ground is not perfectly level, no problem. If the ground is too much on the slope, or a bit lumpy just place something solid under one of the feet. Long thick grass or shrubby ground may be more problematic. In fact a Dob mount is potentially more stable because the tube assembly is supported on both sides rather than one. Ed.

I cannot precisely answer that. However I can get very close, because I have a NZ 3-6, and an original series Vixen LV 2.5. The LV 2.5 is more comfortable in use because of its 20mm eye relief. But in other regards it compliments the 3-6 excellently. I’m a double star fan, and on nights of decent seeing the 2.5 teases out those very tight doubles that are so satisfying when finally, a split is confirmed👍 For me, the 2.5 is a specialist tool, the 3-6 more useful more often. Off topic- Those of us who remember the LVs introduction in the 90s will recall how amazing they were. The 20mm ER was a game changer, especially in the shorter focal lengths! Similarly the 3-6 with 10mm ER is luxurious compared with times past when very high power meant almost attaching your eyeball to the glass! Ed.

If you pm me your address, I’ll send you a 1.25” parfocalizing ring for free😊

I’ve enjoyed many times at Kelling star party, the great skies, great company, the trade stands and secondhand stuff…. One year we had FIVE consecutive clear nights in a row. I felt compelled to use them all, but enough is enough and I was desperate for a cloudy night so I could…………😔😔😔😔😔😔😔

The mirror must have a tiny amount of slack. With due respect to popular opinion, a credit card is a bit too thick for measuring how close the mirror surface is from the clips. I’d suggest something much thinner is sufficient, whilst still leaving a tiny gap. This works for me- A piece of stiff paper. For radial movement, gaffer tape or similar can be used to fine tune the tiny gap needed between mirror and side restraints or cell.

On 25th March 1991, George Alcock aged 78, using 10x50 binoculars through double glazing, made his final discovery. Nova V838 Her. Confirmed by Denis Buczinski

As above….. About the only exception could perhaps be with binoculars. You would need the room lights off to prevent reflections. The late great George Alcock used binoculars through glass as he got older. If you’re elderly and poor health makes heading outside in the cold a tough call, then the compromise of viewing through glass would be better than no views at all.

Welcome to SGL lots of folk on here ready to help😊 Never used Stellarium but many do and recommend it. The smartphone adapter may be useful. But please be aware that many of the fabulous images you have seen will have been obtained by dedicated imagers with expensive kit. Best to start with visual and see how it goes. The BST Starguider eyepieces available from our sponsor FLO are recommended as likely the best available for the price. I’ve used most of the BSTs and the best of those were the 5mm 8mm & 12mm. Cheers from Ed.

Hi Gerry, enjoyed your enthusiastic report👍 My highest power eyepieces are the venerable TV 3-6 zoom, and a Vixen LV 2.5. In excellent and rare moments those eyepieces work well, giving satisfying views on double stars. But I’m told by a trusted local friend that high end fixed focal length eyepieces beat my 3-6 zoom, and my LV 2.5. I can see in your equipment list you also have a 3-6 zoom, your comments appreciated. Ed.

Welcome to SGL! There’s several reasons for poor views with your scope- Collimation- alignment of the mirrors. Not in precise focus, stars should appear as tiny points. Cooldown- applies especially to mid to high power viewing. Possibility of viewing a galaxy which will always look like a fuzzy blob. Bortle 3….I’m not envious, I’m VERY ENVIOUS INDEED😊

Late to the party (again🙄) I noticed this scope has 3 pairs of collimation screws, same as my early model Vixen 80/910 achro. Never needed to collimate mine, but their presence shows they cared how they were made. Simple but effective ‘old school’ construction. Nice to meet some of you recently at Kettering 👍

I’m not bothered if they match as long as they keep my feet WARM🥵😊

Ditto eyepiece advice👍

Thanks Stu. Your image shows NGC 1502 at the lower end of the Cascade. For those not familiar with this, take a look at the lower end of the Cascade in Stu’s image, where it divides into an upside down Y shape. Next to the shorter part of the Y you can see tiny NGC 1502, with Struve 485 as an elongated star. Higher power brings out this open cluster and the double star nicely. You don’t need a large aperture to do this, even from town. My 70mm Pronto gets the job done. Genesis would do it better😊 For new folk. Don’t believe those who say you can’t do enjoyable astronomy from town, because you most definitely can!! Ed.

Yesterday at the Practical Astronomy Show I got into a discussion with visual observers about my use of NGC 1502 as my name on SGL. So I thought an explanation would be fitting on here. It’s quite simple actually…… Many of you will have heard of Kemble’s Cascade (Kemble 1). It’s a 2.5 degree long alignment of stars in Camelopardalis, a dim far northern constellation. It’s an asterism brought into prominence by a Canadian monk called Lucien Kemble. Lucian wrote to Walter Scott Houston (Sky & Telescope magazine) about a “beautiful cascade of faint stars tumbling from the northwest down to the open cluster NGC 1502. In 1980 Walter called the line of stars “Kemble’s Cascade” and the name stuck. NGC 1502 is a tiny true open cluster. Within the cluster is double star Struve 485. So- three objects in one, an asterism, open cluster plus double star. It’s circumpolar from northern latitudes therefore available all year, but best viewed in winter. Kemble’s Cascade is a nice binocular or low power wide field scope object. NGC 1502/Struve 485 best viewed at higher power. Enjoy😊 Ed.

I suppose I have to reluctantly agree, that in today’s market a TV Genesis can easily be beaten by modern premium refractors. And yet I have to admit that ownership is not always completely logical. Some of us yearn after cars made decades ago. Have you ever watched “Bangers and cash” on television? Owners and potential owners (and me) drool over cars from yesteryear. There’s just something about them that modern cars cannot satisfy. Are those cars more efficient, more reliable, more comfortable, easier to maintain, have better performance than modern cars? No……but as I said earlier, it’s not always completely logical. I own both a TV Pronto and a Skywatcher ED80. Same comparison! So if you already have a TV Genesis, or still want one, just go ahead and enjoy it😊 Ed.

Whilst I’m not able to help with the scope questions…..I’ll just comment on your sad loss. That’s because I share your pain having lost my dear wife Ann 6 years ago. I know how hard this is to cope with. We’re all different in the way we go forward after we go through deep pain. But one thing I can say is if you can fill the void as best you’re able, to build a new life. We have to accept that life will never be the same. But that doesn’t mean we cannot go forward building a new life. Your request for help with your astronomy kit does mean that you are picking up the pieces and attempting to go forward. Your journey will be different to mine, but I wish you well and hope that eventually the pain will lessen as it has for me. One further piece of advice if I may. Best not to make any big changes for a while, like moving or finding new love. Give it time, you’re still in shock even if you don’t realise that. Take care, and all good wishes, Ed.