Posts Made By: James Adams

What a hoot! It has to be true, and as an old hippie [Haight-Ashbury, 933 Stanyan Street 1967]it sounds like some deals for other things much sought-after at the time!
To paraphrase an old saying, "scopes will get you through times of no money better than money will get you through times of no scopes."

Marty,
Try John Hopper at AstroBuffet.com; he's very knowledgeable and provides excellent service and communication.
James Adams

Mike,
Excellent ideas. May I add:
A planetary Dob, like, perhaps a 6" or 7" f 10 with low profile focuser and minimum obstruction?
And a solid mid-size mount, more solid than a G-4/G-5, with wooden tripod, in the $300 to $500 range? [Help Stamp Out Shaky Scopes!]
Thanks

Mark,
I think a 90/1000 will be undermounted on a G3. I got my son a SpaceProbe 130 on that mount and soon traded him up to a G4. I took the G3 for an FS 80 scope with a Coronado 60 mm. filter, and even with a lot of modifications to the mount and tripod it's spindly. The Coronado filter adds a couple of pounds to the OTA, but still, it should be more solid. There always seems to be one more thing you have to do to get it to settle down.
Even the CG 4 requires some mod's for serviceability, and I, personally, find it inconvenient to use. I kind of think that if I had it to do over, I'd plan the scope around the mount, making sure it was rock-solid. To me, there's nothing more annoying than trying to view, or even focus, with an object jiggling all over the place.

Mad,
You might find a used Celestron Firstscope 80 on Astromart [I bought one for $55 + shipping] and use the 90 mm. tube, which is black inside and baffled, for your project.
James Adams

I have the 8.5" f 12.5 Chinese made refractor lens in cell in a tube I made. It tests well, except for a slight turned edge which led me to stop it down to 7 3/4". It gives very nice low power views when seeing allows, and can be good on planets to over 300 X. It shows some slight color on planets, and on stars at higher powers, though not much at under 100 X.

There Ain't No Such Thing As A Free Lunch [TANSTAAFL], a principle of the universe [see Einstein, Murphy, Feynman, et al.] applies. You can't have larger aperture and shorter focal length without increased color, all things being equal.

This, in itself, is not necessarily a problem, if colored halos don't distract; but the color is also only a symptom of what's worse, loss of detail and contrast resulting from colors coming to focus at points perpendicular to the image plane. Since the colors most affected are at the ends of the visible spectrum, the effects may not be immediately obvious, until you compare the view to what you see in a similar aperture/focal length apochromat.

I purchased a Celestron Firstscope 90 f 11 on Astromart for under $60 and replaced the objective with a Vixen Research Grade achromat. Same size, f.l., slipped right onto the existing tube. Had to tune up the focuser a bit, but it is a delightful little telescope now.

I did the same thing with a 4" f 15 achromat tube, and it's my favorite now, on a G-4 mount I picked up for $200.

Whenever I need to lay out complicated cabinets in my shop, or for nearly anything round or with other than 90 degree angles, I lay it out full-size [or you could scale it to 1/4 size] on cardboard. Hardwood plywood comes with 4' X 8' cardboard cover sheets perfect for the job. One side is used for the face [elevation] view, one side for the plan [top] view, and another sheet for the side view. Each piece of building material should show up in each view, enabling you to take dimensional measurements and cut angles so that all goes together perfectly. Your balsa model would help at this point to envision how everything goes together.

If it is possible to lay it out full size you can mark for cuts directly off the cardboard without using a measuring tape, and everything *has* to go together perfectly! [Hint: use pieces of the actual materials when marking them in on the cardboard to remove variations between "nominal" and actual thicknesses.]

One advantage of this method is that you can include windows, doors, electrical, sheet metal, and other considerations; see clearances in actual size; and even be sure your equipment fits the enclosure!

James Adams

You can take the tour, but if the weather turns cloudy, they might cancel; this happened to me. You aren't supposed to drive the rental cars on the saddle road, which cuts across the island and takes you to the Mauna Kea turnoff, but with one day left and no tour, I chanced it. It's not as bad as you might imagine, paved and little traffic. A jeep would be quite unnecessary.

You will need to stop awhile at the visitors' center at 9000' altitude to acclimate. My understanding is that access to the summit may be limited now, I don't know. After leaving the visitors' center we drove up to the observatories. I almost fell on my face when I got out of the car. There's no air up there! It was amazing to see all the domes.

It was cloudy when I was there, but you can see what a wonderful spot it is. There are many places between the base and the summit where you could pull off the road and set up a scope, although I'm not sure if there are rules about that.

Good luck!

James Adams

As a professional cabinetmaker, I get Finn birch, also known as Baltic birch ply. In the 1/2" thickness it comes in 5' X 5' [metric sizing] sheets, and is also available at most wholesalers in 8' X 4' sheets [the grain runs the SHORT direction, so it's cross-sanded]. Either way, it's nice to work with, hard and stiff, and resists weather well. You should pay around $1.50 a square foot for it, or less.

Appleply comes in 4' X 8' sheets, and is, I believe, a domestic product, also 9-ply in 1/2". It has a nicer surface, IMO. I think both products are available in other thicknesses.

Many wholesalers will sell to the public. You have to call them and find out.