Tuesday, January 19, 2021

Bitten by the Bug -- Again!

View from the Other End
Bitten By the Bug, Part 1
Sky Research 8” F/2.9 Dobsonian, circa 1981
My first serious telescope, a Sky Research 8" F/2.9 Dobsonian, circa 1981

Bitten by the Bug, Part 2

In the early 1980s I used the rich-field Sky Research dob for a number of years, but was keenly aware of its shortcomings. While it sported an unrivaled F2.9 aperture, ideal for dim, extended objects requiring more light grasp than magnification, it was a poor planetary scope, due to its short focal length and large secondary mirror obstruction. Still, I kept it in the camper shell of my Toyota truck, to have handy whenever the mood struck. And I enjoyed some spectacular views of nebulae, in the mountains of northern New Mexico at night, where Orion's nebula shone like a Hubble picture.

Sky Research 8” F/2.9 Dobsonian Reflector

And then one morning, on the way to work at the TV Repair Shop, I got in a traffic accident, and the scope was thrown around the back of the camper shell, which fractured the composite body tube around the eyepiece focuser mount. I put the scope into storage for a number of years, until I could decide what to do with it. Years later, I replaced the 9.25 inch diameter body tube with a 10 inch diameter construction type concrete form tube, which required replacing the glass aperture plate (the original scope had the secondary mirror mounted to a clear glass aperture plate up front, with no mounting spider like an open-tube Newtonian), with a makeshift threaded rod and plumbing cap secondary mirror mount and spider. In the process I painted the new body tube red, with the rocker box now white.

Inside the Rich Field Newtonian

I was still looking for a stargazing solution, however. For a while I used my Dad's Edmund Scientific 4.25" newtonian, which he'd bought in the 1950s. I remember one summer night at Altura Park viewing Mars at opposition, and sketching surface detail in that scope. It certainly performed above its weight limit!

Tasco 3”, 700mm Reflector Telescope

One thing led to another, and eventually I was left with the red/white/blue shorty dobsonian, and a beaten up old Tasco reflector, the kind once sold in department stores. Not the best instrument for a serious amateur. It's this little red scope that I've been having fun with recently. It's easy to take down and store in my garage, and gives an adequate view of brighter objects from the city. But I'm keenly aware of its limitations.

Zhumell 25x100 Astronomy Binocular & Case

This isn't the first time I've been down this road, being bitten by the astronomy bug and wanting a better viewing instrument. Within the last decade I started using a 7x50 binocular, mounted to my Bogen camera tripod, and enjoyed the views, and especially the ease of setup, tear down and storage. But I wanted an instrument with higher magnification and light grasp, so eventually got these Zhumell 25x100s. That's 25x magnification and 100mm (about 4") aperture. Bigger than the little red reflector's 3" mirror, almost as big as my Dad's old Edmund Scientific reflector, though a much shorter focal length, and fixed magnification, as the eyepieces aren't removable.

Zhumell 25x100 Astronomy Binocular

Forget handholding these babies. It's not even a suggestion to have a tripod, but mandatory. They weigh north of 15 pounds. But I've had some fun viewing with them, using both eyes, first using my Bogen camera tripod (which is almost too flimsy for them), and later with this cobbled together-frame that positions the binos at eye level, reclined in a zero-gravity lawn chair. Perfect viewing comfort.


But alas, this frame is too large to store with easy access in my garage, so has been relegated under a pile of clutter, along with the folding chair, in my storage shed. But I have been busy sketching ideas of different binocular mounts.

Parallelogram Binocular Mount

First is my version of a parallelogram mount. This is an articulating arm, mounted to a tripod, that attaches the binocular to an L-bracket on one side and is counter-weighted on the other. This kind of mount permits the binocular arm to be moved up, down and sideways without changing the aiming point of the instrument. Set a reclining chair next to the tripod and you're all set. These are available for purchase, but this was my sketch of a homemade version.

Astronomy Binocular Mount Studies

Next are two more sketches. The one on the left is an alt-azimuth mount that attaches to a tripod and has those low-friction bearings like on a Dobsonian reflector scope. The problem with this idea is the eyepieces don't have 90-degree prisms, so pointing the instrument at the zenith means getting in an awkward position underneath. And because the tripod's directly below the instrument, there's no room for a reclining chair.

The sketch on the right is for a counter-weighted frame that positions the scope in front of the user, reclined in a chair, with the up/down pivot of the frame being located adjacent to their ears, meaning as the viewer tilts their head up and down the binocular can follow with the eyepieces right in front of them. I didn't show the rest of the idea, which is a reclining chair mounted to a rotating platform. While it would represent the ultimate in binocular viewing in comfort, I'm not convinced of its easy of storage or portability. Oh well, at least the idea is documented on paper.

Since I did drag the short-tube Dobsonian out of the storage shed and cleaned it up (except the mirror is still needing cleaned), perhaps I'll put it through its paces during these next few weeks, and see how I get on with it, before deciding on buying either a parallelogram mount for the big binoculars, or a larger, longer Dobsonian-style Newtonian. And if I do decide to make another gear acquisition, it's incumbent upon me to give my older gear away to someone who'd appreciate it, perhaps starting their own journey into star gazing.

These are the problems of a part-time sky watcher, who has bigger dreams than his pocket book or available room can accomodate. But I suppose there are worse problems.

Stay well, and keep looking up.


Monday, January 11, 2021

EKG Paper Typing

EKG Thermal Paper & Canon Typestar 4
EKG Paper Typing

This EKG thermal roll paper is thin -- thinner than the Brother letter-sized thermal paper sheets that I like (and return-gifted a pack to Gregory Short, in exchange for him sending me this roll of paper). But it's still thicker than the Staples-branded fax paper, and prints darker. I think I'm going to like it.

I do need to make another dispensor holder for this new roll; my other holders still have paper in them. I'm thinking about making it as simple as possible, simple enough that almost anybody could make one. And I'll use one of those thin metal serated tear-strips from a pack of plastic wrap or aluminium foil. Probably use a bamboo skewer to hold the roll in the dispensor. Maybe a video about it.

Canon Typestar 4

I like that the front, thermally-sensitive side is rolled facing inward to the roll. It seems to protect the coating better. And once rolled through a thermal typewriter, it tends to reverse-curl the paper to flatten it out rather well.

Since this paper was a gift, I do need to find the source online, and determine whether the price is sufficiently thrifty to recommend to others. But I really like the dark "imprint" it makes, along with the nice grid pattern. Thank you again Gregory for this gift!


Tuesday, January 05, 2021

Typewriter History

1961 Hermes 3000
Typewriter History, Page 1
From Sandia Lab News, June 8, 1962

Typewriter History, Page 2

Here's the video I made of Sterling Carter's Remington: