Posts Made By: Bill Byrd

[COLOR="Purple"]How about a 20" f/3.5 mirror, 4.5" diagonal and a coma corrector for $3K USD? Found for sale on another web site specializing in Intes products.

Specs say the mirror is "special low expansion" glass, image plane wave front: 1/6, with a 2" cental perf designed so the mirror can be mounted like a conical using the central perf.

This is tempting to me after the trials I've been through trying to make an 18.75" f/5.22 cellular mirrored scope work. The long focal length and light weight mirror makes for very large mirror & rocker boxes and necessitates a ladder for almost all viewing.

A slight step up in mirror size (and weight ) would give me a much more compact scope to deal with. It's tempting to consider!
Bill[/COLOR]

[COLOR="Purple"]Hi All!
Johannes Schedler's beautiful astrophoto of the day today clearly shows UGC 5336 next to M81. I never thought to look for it but now that I see how close it is to M81, I was wondering if it's worth a try. It's mag 14.4 so it's faint and being so near M81 might be a problem...swamped with the photons from big brother?

Anyway, has anyone seen this little guy? What aperture and magnification?
Thanks!
Bill[/COLOR]

[COLOR="Purple"]After nearly 40 years of using telescopes, some bought, most self built, I'm finally going to have a Feather Touch focuser of my own! Thanks to good luck and timing I managed to buy a Feather Touch from a fellow Astromarter; thanks Frank!

I've always had good focusers on my scopes and I appreciate how well they work. Having used Feather Touch focusers every now and then on other folks scopes, I've had first hand experience with how smooth they are. So now I'm anxiously awaiting delivery and contemplating the rebuild necessary to fit it to my big scope. The current focuser will probably be relocated to my Meade 8" SN which definitely is deficient in the focuser department.

Soooo...what's everyone's favorite focuser and why?

Me, I like any focuser (helical, R&P, crayford) that is well designed and executed but it must be smoooooth. Nothing worse than a focuser that sticks or jerks when focusing.
Bill[/COLOR]

[COLOR="Purple"]Inquiring minds want to know!

The thread about using AA batts to power fans has me wondering: Why are rechargable AA batts rated at 1.2V when disposable AAs are 1.5V?
Curious,
Bill[/COLOR]

[COLOR="Purple"]Just noticed that SV (Stellarvue) has a new 60mm finder listed on their web site. With all the raves about the 50mm and the new (relatively) 80mm finders, I wonder if this one will be another winner. Frankly, the 60mm size is tempting to me.

Anyone seen or used one of the 60mm finders?
Curious,
Bill[/COLOR]

[COLOR="Purple"]I seem to recall a map/drawing with star magnitudes shown for the stars in and aroundthe Trapezium. I can't find it on Google. Anyone have a link to such a thing?
Thanks!
Bill[/COLOR]

[COLOR="Purple"]Here's my project du semaine! Like I need another project!!

It's an '80s vintage Meade 60mm finder. I picked it for a song (Thanks Mark!) as a rehab project.

It's obviuosly well used but seems to have decent optics with the original .965 EP. The focuser is helical and fairly smooth. There are a lot of screw marks from the rings it was mounted in. Other than those, the OTA is in pretty good shape. Every part of this thing is metal as far as I can tell. No plastic here!!

The diagonal is is pretty bad shape with a crack and corrosion/rust on the back screws. It will probably have to be abandoned in favor of a hybrid .965 to 1.25" diagonal. Then I can use whatever 1.25" EP works best...I'm betting the 19mm Panoptic will be a winner!

So far I haven't been able to remove the dew shield from the objective cell. I'm assuming it's a screw on but maybe it's a press fit? I had another refractor that acted the same way and I had just about given up on it when suddenly the dew shield unscrewed easily. I'll try some gentle persuasion with strap wrenches to see what happens.

Long term I want to clean everything up and do a nice paint job on it. I've been wanting to try a refractor paint job and this baby just screams out for new paint. Some Bondo...some sanding...cool paint...and this thing will be pretty cool!

More as I progress....
Bill[/COLOR]

[COLOR="Purple"]Welllll...the "Diamond in the Rough" Meade 60mm finder is in the process of being transformed into a beautiful jewel....hopefully.

My first idea was to use purple "anodize" paint. It works but is a lot of work to get it right.

I had some silver metalic sparay paint so I tried it.

The pic shows the body in silver and the dew cap in purple. I'm leaning toward doing it all in silver, with the original black parts done in new gloss black. A backup plan is to do some sort of a pearlescent on the body and dew cap.

Any thoughts?
Bill[/COLOR]

[COLOR="Purple"]...of in-field repairs. Or something like that.

I was out in Big Bend National Park this past week for an observing trip and my EQ platform quit tracking. Turns out it needed a recharge of lapping compound to give traction between the drive wheel and the sector that rides on it.

I failed in two ways: 1. I didn't think to tune up the platform before I left, where I would have noticed that it was time for a recharge. And 2. I didn't take the lapping compound with me in my usual in-field tool kit. DOH! :S

So after 2.5 nights of tracking, I was suddenly not tracking. The next morning I figured out what was wrong but had no way to get ahold of lapping compound out in the middle of no where. So like any good scope builder, I used what I had available to make a fix. Since lapping compound is basically grease + grit, I tried to figure out what I could substitute in the field. I decided that toothpaste would substitute for grease and dirt would substitute for grit.

Here's a pic of the drive wheel after an application of minty fresh UltraBrite toothpaste. As a bonus, after the application of the toothpaste, the platform smelled so nice, although that might have been a bad thing being in bear country.

In the next post you'll see the drive wheel with the dirt on it.

Bottom line, it worked during daylight testing but the 50mph winds that night kept me from trying it out on any stars. I'm pretty sure it would have worked okay for maybe one night, perhaps with a recharge of the dirt needed during the night.

Now that I'm home, I'll clean everything and rechage properly with lapping compound and I'll throw the lapping compound in the tool kit.

Use what ya got if ya don't have what ya need!
Bill[/COLOR]

[COLOR="Purple"]I was in Big Bend last week to take advantage of the oh so dark, and luckily clear, sky at night. After being up most of the night for the first three nights, I managed to get some pics during the days.

Here's a clouds-at-sunset pic of the peak named Casa Grande.
Bill[/COLOR]