haunting the usual place, Vancouver telescope. I have managed to find so much to interest me there. Nick seems to have new stuff most visits, and I will kill a few hours talking and looking.

This time there were a number of parts and a sonotube. It was what was left from a 10″ f/4 Dobsonian  F/4 is a very short focal range for Newtonians, but quite common NOW. When this was ground, polished and then coated at Pancro in the 60’s or 70’s, f/4 was unusual. Very few would have parabolized a mirror in this range with any degree of competence.

The mirror has little to identify it: a sticker from the coating  company, Pancro, and a focal length inscribed with  ‘ 39.8″ ‘ a cell, spider and secondary holder by Kenneth Novak, very well known and regarded in amateur and professional circles. The focuser was only a 1 1/4″, far too puny to delivery wide field viewing with 2″ eyepieces.

I am proceeding down the same road as my 12 1/2″ build, using baltic birch plywood, a very hard and dimensionally stable composite wood product. It usually comes in standard imperial thicknesses (1/4, 3/8″ and 1/2″ are my usual picks). The size is 5 feet by 5 feet. making it very tricky to cut up to smaller sizes, even on a 10″ table saw.

I cut a strip 10″ wide and used a finger-jointing jig I have used on many other projects.

The first was a case for an 8″ Maksutov M809 by Intes, the 2nd an eyepiece case out of Jatoba and the 3rd a case fror my smaller MN-61.

Quite simple to use, you can make it yourself as you need different ones for different finger widths. The tools you need are a table saw with adequate capacity to take a dado blade set.

The part is just a board with a finger of wood the width of the dado you are cutting. The finger acts as a registration point to cut the slots, and you then put the dado you just cut over the finger and repeat until you have cut all the fingers. For each side of the box, you gang the sides together in pairs to get them identical. For the second pair, you ADD a piece of wood between the finger and the plywood to get an offset. It should be close to the width of the dado but it doesn’t need to be exact, as any unevenness can be planed off once glued up.

You can add a gusset of wood, cut at 45 degrees to reinforce the interior of the box for robustness. If you need to make the box lighter for balance or other considerations, just use your table saw to rip a section off end end

 

You just need to test it first to make sure the gap is correct. I am testing a few scraps out to try veneering to surface of the wood for a more refined look. I have a choice of using maple, cherry or walnut. I am leaning towards walnut but that means I will have to match and tape together sections to do each side correctly.

I have been of the receiving end of ATM luck for some time, mostly good luck as this is not as popular as it once was. Telescopes have been much the same. Since I got my two Maks though, I haven’t been as tempted as before with two exceptions. I got a 80mm scope as it was on sale used for a decent price

My first was a 12 1/2″ blank someone had made a start on but quit. I got it for $100 (less than half its usual price AND part of the hard grunt work of roughing done). It has gone slowly, my time eaten up by laziness, sloth, Diabetes and the work involved in paying for and maintaining a house.  I have restarted it but need to test it again to be sure where it lies, and if it needs more polishing. I now have the frame and box complete, it needs a mirror cell, a trunnion and a way to connect the top to the bottom.

This years http://www.tmspa.com/ is just south of Osoyuos so a double shot at Mt Kobau is possible. If you’ve never gone, please do it. Maybe I’ll have any entry this year.

I find things at Vancouver Telescope often. The above blank, a new (but scuffed) 3.5″ Newtonian secondary mirror, odds and ends. One was a new in box (since 1965) 10″ mirror making kit, with two Pyrex blanks, all the grit but no polish or pitch for $100. A steal considering its cost in 1965 was $67.50, about $400 in today’s dollars.

 

January 2013

Weather has been poor, so little observing except hauling out my new refractor to try it out. I already own a small 80mm f/6.25 I got 25% off it price at a North Shore pawn shop years ago. I liked the scope for its quick setup. A few things were problematic. My tripod, a large Manfrotto with a bubble level head, has no trouble with my heaviest camera lens, a 200mm f/1.8 USM Canon telephoto. The 80mm ED with its long heavy tube overpowers the lock in the tripod head. In an effort to lock it securely, I have now broken the threaded part off twice, making it necessary the file in a slot in the remainder to use a screwdriver to remove. FFFUUU. I have tried it with my Canon 7D, and while it does get a focus confirm beep, the actual focus is a bit soft on occasion. My Canon 200mm f/1.8 has no such problem, focus in manual is unmistakable.

Someone who knows my love of telescopes told me a friend was clearing out some items and gave me an address. He had a few items like a nice tripod and some eyepieces that were duplicates of better ones I already owned. I told him he could go to a local telescope shop as he always had people coming in looking to add eyepieces but I was interested in the tripod.

He laughed derisively at my experience with my expensive tripod and said he thought this one would be better. I asked what telescopes he still had and he’d sold the two cheaper ones to some students on budgets. He got a case from the corner with an unfamiliar logo. He hefted the heavy for its size case up to a table to open it. A rather plain white tube with a dual speed focuser.

I have heard about AstroPhysics scopes and even looked through a number of them. I liked their color free look but the cost verses size argument lost me. This one was remarkably short and light for a 93 mm refractor. We set it up on his small tripod and did some observing of the city. Buildings in downtown, over 4 miles away, showed clearly in spite of obvious heat waves distorting the seeing. The white parts of Canadian flags visible on buildings were perfect without extraneous color fringes.  He said he seldom bothered to use his best eyepieces with it as it did fine with unremarkable Orthos or even Plossel EPs.

We covered it with a cloth and he got me some tea and biscuits and we talked while the sun went down and the near full Moon came up over Burnaby Mountain. We resumed observing, this time on a dark orange target hazed by pollution. It got clearer with altitude and he started showing me around all the little features I’d never bothered to learn the names to. Craters were nice in spite of the lack of shadows due to the near full phase.He got out a set of eyepieces in a box made of walnut. I KNEW what these were, a matched set of Zeiss orthoscopics.

I had wanted a set of these, being a camera buff who revered the name Zeiss but few ever showed up for sale. Neither did these 🙁 He targeted a number of double and multiple stars and the color contrast between them was very evident, not like my refractors more indistinct view.

Obscure rilles, domes and smaller craters dotted the area. One I had seen before in my 6″ only stood out due to its shades of grey being a bit lighter than the surrounding Even small craters in the bottom of Plato were quite clear. He informed me this little scope was one of their special projects,never repeated or equaled, called the “Stowaway” for its very fast f/4.9 ratio. He got me an adapter for my Canon and I hooked up my 7D. The city photos were clear and crisp, no autofocus but with its fast ratio the cameras sensors did work and give me a beep for focus confirmation.
A few pics of the moon, using care to use high shutter speeds to reduce glare and get proper contrast were in order. It use one of them for my wallpaper on my home computer.

I bought it for his asking price, too high for my taste, but fair considering it was around that price new back in the day. So far I haven’t used it too much. Just around Squamish for some pictures and some eagle watching this winter. I must say the white paint doesn’t cool off like my black tube refractor and frost up as easily. I didn’t realize what a desirable scope this was until using it and since then a few others who have seen/ looked through it have. One person who saw me using it was invited to look through it for a while and when he took a good look at it, must have know the scope, at least by its legendary reputation in astro-photography circles as he asked me if I was considering selling it. I just gave my head a quick shake and he gave a sigh and a small frown, his close encounter with this scope likely to be his closest one.

I took time to really star test it and was quite please with the results. A 5mm Nagler plus my 2X Big Barlow gave me around 190X. Jupiter showed its subtle color differences between zones that I never noticed before on my other refractor. Even the faded Red Spot was clearly visible near one limb. He sold me (for an extra $400) a small set of matched EPs called monocentrics. These are more specialized eyepieces, made either from a single piece of glass or several types cemented together. This means (back when coating glass was expensive and not as good) you had fewer air to glass surfaces from which light could scatter, meaning brighter images. The down side is you have a narrow field of view, typically around 30 degrees or less and little eye relief.

Jupiter was astounding with a 2mm and slighter better when I added a baralow. I had to admit it was fuzzy but subtle bands boundaries were visible intermitantly.