badhex

Thanks Peter, I know that it would not be much work given how close RAS is to 1.25". That said, I don't have the required tools, plus I'd like to not modify the original focuser really. I was actually hoping you might reply given your vast experience. Do you think what I'm suggesting as an alternative would be possible?

Hello all, I would love to give my old Charles Frank 6" reflector a new lease of life, however being the age that it is, it accepts only 0.965" or RAS threaded EPs in the helical focuser. I do have a collection of decent 0.965" EPs but would love to use modern EPs in it as well. Since it is a newt, a 1.25" adaptor will not work here as there is not enough in focus to account for the adaptor. I also don't really want to replace the whole focuser, as it also mounts the WW2 gunsight which it has for a finder! In light of this it occurred to me that perhaps I could actually get a new focuser EP holder part made with say a T2 connection on the end, allowing for connection of modern adaptors, EP holders etc. I think it might actually be quite simple to make. Here is the existing focuser tube plus RAS-0.965" adaptor: I don't have my thread gauge and calipers to hand but essentially, it would need to be a tube of probably about 1.5" diameter, threaded on the outside (my guess is a fine imperial thread of some sort). Towards the top I'd need a wider collar to grip for focusing, and then finally T2 threaded for whatever EP holder or accessory I decide upon. So, who could I speak to who might be able to do this? Beacon Hill might be an option I think if they are still going, though I haven't been able to get in touch yet. I don't know anyone else who might have the required equipment to do it. If anyone has suggestions, maybe someone here who has the skill to make such a thing, I am all ears!

Funnily enough I actually did manage a quick test about two weeks ago and made a few notes. I thought about posting but hadn't, however I'm now inspired by @grjsk so I finally wrote it up below: Skies were clear-ish so popped out for an hour with the converted Evoguide 50ED on my dreadfully light polluted balcony, as it has been barely tested since I built it last year. Transparency average at best with some high clouds, seeing also distinctly average, so not the best conditions! Started with the 24mm APM UFF at 10x on Lyra. Not many stars visible; I suspect some clouds to be the culprit. Although it might be a good challenge for another night, no chance of splitting the second pairs of the double double under these conditions, so moved over to Albireo. Split with Pentax XW 10mm at 24x , clear and obvious with the Morpheus 4.5mm at 54x but no nice defined star shapes. Bigger fracs give lovely pinpoints, but some aberrations in here somewhere, seemingly even when on axis - the scope also didn't have time to cool, really. More investigation needed. Swung back to Lyra to try for the Ring. Not sure a 50mm scope can do it under London skies, but after some switching about between 10mm and 4.5mm, I was just, really only just, able to pick it up with averted vision. No defined ring shape, but definitely a presence. The ghost of the ring, you might say. Saturn still slightly above a building so I suspect thermal disturbance from that did not improve the views. Reasonably sharp with the 4.5mm at times, but not able to pick up any moons. 10mm much sharper and Titan could be resolved at about the 10 o'clock position relative to the planet. Some phasing in and out of focus. Time was up as clouds were moving in so I called it a day. Overall not the best session but better than *no* session. Definitely some mechanical issues to resolve with the 50ED regarding the focuser mechanism; what I have discovered (which should have been obvious I suppose) is that because the focuser is quite low profile, I needed more space between the focuser and diagonal for EPs with longer barrels. I've since rearranged the order of extension tubes etc. to hopefully solve some of that. Looking forward to another session!

Great report, glad you managed to get some clear nights. I have never looked through anything larger than a 12", but the sight of M13 through it will live with me forever!

I just read your first light report @philj so had to go back and find the refurbish post too - great stuff! I have a Charles Frank 6" reflector from around 1960-1970 ish which is in working order but needs some love. It's been in storage for quite some time, during which I picked up a few more 0.965" EPs but I've been reunited with it recently so want to give it an outing sometime soon. BTW slightly off topic, but @HAsun I think you would be able to repolish the speculum mirror by using a convex pitch lap matched to the mirror. From a blank, you'd start with a matching convex brass/speculum grinding tool with progressively finer grit (sand in those days I think) and then eventually using fine polishing powder and a pitch lap. I guess, although I'm not an expert, that you might be able to just skip straight to the pitch lap since your mirror is already ground to shape. There's a short video on the process below. It's basically the same process with glass mirrors these days, with the final stage after polishing being the aluminium coating. I know Terry, the expert in the video, and attend mirror making classes with him. I'm sure if anybody here ever needed speculum mirrors repolishing or glass mirrors recoating he would be able to help. He recoated my Charles Frank mirror and did a great job, so I ended up attending the club and making a 10" mirror.

Congrats on ten years! Like others I've also been convinced to part with funds thanks to your site, in particular the great review of the Vixen SG you did. Here's to another ten years!

Excellent writeup, looks great! I think I mentioned that I had considered this scope early on when I was looking at a tiny setup, so it's nice to read up on some real world experience - it scounds like a great scope. Clever approach with the ball head, did that come with the tripod or bought separately? I like the look of the case also, I've not managed to sort anything out for travelling yet. What are the internal measurements? One thing you may want to watch out for is diagonals with that design have quite a large lip inside the EP side, as well as a sleeve inside the scope side, which reduces the clear aperture by a surprising amount and might cause vignetting. Obviously it's only an issue at the widest field views, and may not be that noticeable. Anyway great stuff, looking forward to hearing more adventures!

Excellent! I'll give it a read, very interested to hear how it performs. On a related note, I wrote into the Actual Astronomy podcast with a few topics, one of which was the ultra-portable concept, what they refer to a 'suitcase observatory', and it got a small mention! Email from about 14m20s on the episode "Oddball accessories". Not sure if you listen but I'm sure they'd love to hear about your setup too.

Interesting! Yeah, I strongly suspect that even under ideal conditions the 73mm won't be enough, but hopeful for the 102mm. Depending which calculation you use, a 102mm frac could have a limiting mag of up to about 12.7. I spotted Dione last year with that scope, which is only just over one magnitude brighter than Enceladus. By the way, Stellarium is reporting mag. 11.8 and Skysafari 12.1 for Enceladus at the moment. Not really sure where we can get real-time mag values but I'm sure they must be knocking about somewhere.

Congrats! Excellent work, especially given the close proximity of Tethys and Enceladus to each other! How dark are the skies where you are?

Sorry Nik, didn't see this at the time. The screengrab you posted looks promising, what was the date for that? I might as well get in the diary! 🙂

Great report, and some excellent targets there! Clusters, both open and globular, are some of my favourite objects to observe. I've also resolved (hah!) to get more PNs under my belt as they are also fascinating. As previously mentioned, Oiii and UHC filters will definitely help there, but darker skies will help more if you get the opportunity. Unpopular opinion, perhaps, but I have always found M31 to be quite underwhelming - however, I have always lived in cities. A few years ago I was on a tiny, dark island, and saw M31 naked eye which truly is a sight to behold!

Just remembered I picked up these two for a pound each second hand and forgot to post them:

Yes! Actually, it's barely been run. I bought it just before I moved countries, so it has sat unused for 8 years. It will only be used as a lightweight file server so should still have a few years left in it!

No, this is a mini-bar in disguise:

A non-astro purchase; was looking at small comms racks for some home network bits and bobs and then this Excel 20U rack came up second hand and in excellent condition for £50, worth about ten times that new! Probably (quite) a bit bigger than what I currently need but I'm future proofing myself for when we buy somewhere and end up building a home office, and was also cheaper than the smaller, new racks I was looking at. I've already filled it with vintage/retro computing stuff 😂

I wrote into the Actual Astronomy podcast about a few topics including the Enceladus challenge and it got a small mention!

It's a good shout and but as at today, light from saturn only takes approx 1h15m, and would have been a bit less a month ago. I suspect a temporary issue with Stellarium, which I think is now resolved.

You know my next question. But does it have slo-mos? 😂😂😂

Sagittarius is a constellation I usually only get to see on holiday with a 73mm - wish I could view it with a 10" dob! I hit a few of the same targets a few weeks ago and I can only imagine what it was like with that huge aperture 🙂

Cheers Mark, as I recall there are a couple this month? I'll try to get to one of them I think so hopefully I may see you there! Let me know if you fancy a trip south as well for an informal observing meetup one day.

Fantastic report Magnus, a real pleasure to read and a reminder that those great sessions do exist between the endless clouds! Whilst reading I had flashbacks of a session of my own from a year or two ago observing Saturn and Jupiter, first observations of a couple of Saturn's moons (though not Mimas nor Enceladus) and testing out the BCO 10mm plus Barlow combo - a fantastic planetary EP. Going to have to track that down to read now 🙂 If you get your hands on a decent 2.5x Barlow at any point it is also excellent as a 4mm equivalent as well. Looking forward to your next report, and fingers crossed for the rest of the moons on your wishlist!

Thanks for the reminder, I'd forgotten @markse68 was in the general location, although maybe closer to Greenwich IIRC? Not sure how easy it is to get here? I know the Flamsteed AS do something on Blackheath once a month, also on my list to visit.

Thanks @carastro, you're correct, I'm restricted to public transport only. That said I have been planning to come and visit you at the OAS observing evenings at some point, I just haven't got quite that far. Obviously Otford is significantly better than Beckenham LP wise!

Thanks, shame you're not nearer! Fingers crossed some more local members might be interested too.