Posts Made By: Russ Schnitzer

I am trying to decide between a Meade 6" LXD55 AR-6 on the LXD55 mount with Autostar and a Celestron C6RGT on their CG-5 GT mount. Both 6" refractors are computerized, similarily equipped, and in the same price range. Any advice/recommendation is welcome.

There are several small inverters that produce a sine wave output. I suggest you consider these over the square wave output or modified square wave output. At low wattage output, 100-150watts, the price will not be too much greater for sine wave inverters.

I have experience with a much higher wattage inverter (2000w) and have heard stories about difficulties with square wave inverter output. For example, digital clocks that won't keep time and digital microwave ovens whose timers will not function.

There are many sources for sine wave inverters. I have seen them at West Marine, a boating supply store. But, a $boating$ supply will not be the most economical place to buy. Although, they may have the best quality.

Good luck with the project

Russ

At this point, my future observatory is still in the idea and planning stage. I have a location for the observatory identified and have been lurking on various forums trying to see what works and what dosen't and what problems arise with various configurations.

I live on a knoll on a small mountain and have relatively good skies. The major problem is wind. In this regard, a dome would no doubt be superior. However, I find the relative ease of constructing a rolloff roof to be an overriding consideration. But, why not have the best of both worlds? If I split the rolloff roof in two sections so as to be able to move each half independently, it would seem that some of the advantages of a dome could be obtained. The slit between the roof halves could be positioned to allow viewing and yet be narrow enough to give some protection from wind.

Can anyone comment on the concept of a split rolloff roof? Better yet, has anyone done this and can they refer me to pictures?

Thanks
Russ Schnitzer

I think the mount is an old (I know for sure it's old) Superpolaris or just plain Polaris mount & came with a Celestron telescope. The controller is a hand held DMD-1. The RA drive control stopped functioning.

1. The dec. drive works fine. Therefore, the controller is getting power. Works off of 6 AA batteries.

2. When I plug the dec. drive cable into the RA drive socket on the telescope and press a button, the RA drive will slew. So, I conclude that the RA drive motor is ok and the problem is upstream from the motor.

3. Plugging the RA drive cable into the dec. drive motor and pushing a button does nothing. Conclusion, either the RA cable is bad or RA controller electronics is bad.

4. The hardwired RA cable (hardwired into the DMD-1 controller) has a 5 pin plug that goes to the telescope drive motor.

Anyone know where I can find a schematic diagram for the DMD-1 controller? Or, does anyone know what signals and voltages to expect at the RA cable, 5 pin connector?

Russ Schnitzer

From what I read, Naglers are excellent eyepieces for short focal ratio telescopes. That's what they were designed for and if your telescope is near f4.5, they are probably worth the price. But, if you have an SCT operating at f10, it seems to me that alternative widefield eyepieces are more cost effective.

My newly received 16mm Widescan III is a good example. This eyepiece has an advertised 84 deg apparent field and costs $170 (Helix). It sells for approximately half the cost of an equivalent Nagler (16mm, 82 deg, $320). Viewing Jupiter the other night through my older 8" Celestron SCT (f10), I placed the image in the center and watched as it drifted to the edge of the field. Only when Jupiter came to the very edge of the field did I notice image degredation. In my opinion, approx. 95% of the FOV was excellent. Eye relief was acceptable, but marginal. It's a good thing I observe without my glasses.

Unfortunately, I don't have a Nagler to make a direct comparison, but it is hard to imagine the 16mm Nagler being worth the difference in cost. Until I see a difference, my Widescan III will be "my Nagler".

Russ Schnitzer

Recently I bought two 16mm widescan III eyepieces for use with my soon to be delivered Denk II's. Using a Celestron 8" SCT, I tried out the new eyepiece in mono mode and was delighted. Very bright field, fairly wide field, and a crisp image of Jupiter almost to the edge of the field. The eyepiece has an 84 deg apparent field. All this is the good.

My Denk II's arrived and the first night was one of experimenting with different eyepieces and learning the ins and outs of the power switches. I tried a pair of 19mm Pans, 12 mm Orthos and the pair of 16mm Widescans. The Pans and Orthos worked great, no complaints.

Now for the bad. The 16mm Widescans gave me a big problem. The first thing I noticed was that the eye spacing on the Denks became very critical. I mean really touchy. A little change and the view tended to black out. Then, most distressing, when the image moved toward the outer part of the field, it became very difficult to follow with my eyes. Lots of blacking out. My guess is that about 2/3 of the field is fine, but as soon as my eye shifted to follow the image across the field, problems.

Is this effect because of the 84 deg apparent field of the eyepiece? Would this same effect be present in a Nagler(82 deg)?

By the way, the Widescan eye relief is not excessive. I would describe it as just adequate.

Russ Schnitzer

This eyepiece sidewalk testing is interesting, but seems incomplete. Why not repeat the test, only this time, put the caps on the eye end and turn the eyepieces over so sky illumination shines on the field lens side?

Do the results agree with your previous tests? I'd like to know.

Regards,

Russ Schnitzer

After reading the many helpful comments in this thread, I'd like to add my two cents. First, it isn't clear to me that your mirror is definitely the problem. You stated that images are not good. This can be caused by many things. A poorly figured mirror, a poor diagonal, a poor eyepiece, bad optical alignment, a pinched or poorly supported mirror, and bad seeing. You apparently have a mirror that needs cleaning and possibly re-aluminizing. There must be an astronomical society in Chicago where you could ask a member for help in testing your mirror. Before I'd replace a mirror, I'd be sure it was the problem.
Russ

Very nice! What size telescope are you planning for your observatory?

There seems to be a consensus that the Celestron tripod is superior to the Meade tripod. Also, in general, the Celestron GoTo gets favorable comments. Thanks for the information. I still have a little homework to do, but I am leaning toward the Celestron.