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Posts Made By: Fred Dase

December 2, 2006 07:23 AM Forum: AstroMart FAQ

Rudeness or Ignorance ?

Posted By Fred Dase

Hello,
I am new to Astromart. Over the past 2 weeks I have responded to 6 ads in the classified section. 3 were questions about the item and 3 were requests to buy the item at the price and terms listed by the seller. I have never received any reply from anyone.
My question is ... Are they being rude, or am I being Ignorant and missing some protocol required by this board ?

Thanks ... Fred Dase

February 10, 2007 11:08 AM Forum: Eyepieces

Parfocal Formula ?

Posted By Fred Dase

I was out observing last night with some others and had a friends 31mm Nagler in my scope. After giving it back I popped in a meade 26mm plossl (with adapter) and was suprised to see the image was still perfectly focused.

Is there some formula I can use to calculate if eyepieces of different focal lenghts produced by different manufacturers are parfocal, or close to it ?

Also is it parfocal or parafocal ? I see both used freely on the net.

Thanks ... Fred

April 12, 2007 01:01 PM Forum: Equipment Talk

Visually Best 2" Diagonal

Posted By Fred Dase

I want to buy the best 2" diagonal based on what the human eye is actually able to perceive using my SCT. I have scoured these forums reading posts until my eyes crossed, and these are the few points I believe I have discerned.

1) Anything above (smaller) than a 1/8 PV wave front error is not detectable by eye.
2) The telescope itself can/will add to the total wave front error of the view.
3) The manufacturers wave front error claims are ambiguous or at best provide
incomplete information to compare brands.

If I am wrong in any of the above statement's someone correct me please.

These are the major players in diagonals as I see things.

2" VERNONscope Quartz, Silver Coating 1/20th wave (or better) $445.00
2" Astro-Physics MaxBright Diagonal (PMDMAX) Dielectric Coatings $290.00
2" Televue Everbrite Star Diagonal 1/10th [TE-DPC-2002] $275.00
2" W.O. Dielectric Star Diagonal [WO-DIG2DI] 1/10th wave $139.00
2" Baader Maxbright 2" Diagonal 1/10th wave, Baader Maxbright coatings $399.00
2" Lumicon LumiBrite Diagonal 1/10th wave. $239.95

All are listed as 99% or better reflectivity.
Based on the above criteria this would eliminate the Vernonscope diagonal due to 1/20th wave.
Only the Baader diagonal states their 1/10th wave is actually a P-V measurement across the entire surface.
Only AP does not make any wave front error claims (but I know their reputation). They also are the only manufacturer to give you the actual dimensions for clearance of the mirror.

Based on all this "research" I think it comes down to either the Baader or the AP. I am leaning towards the AP because of price. I'm hoping that people more knowledgeable or that at least have a better understanding of all this will offer their opinions. I am in no way attempting to disparage any of the other brands. These are just the conclusions I have come to.

Any help would be appreciated.

Fred Dase

April 22, 2007 06:55 AM Forum: Equipment Talk

Mounting a Nighthawk NG to a Meade 10" SCT

Posted By Fred Dase

I want to mount a Stellarvue Nighthawk to my 10" SCT to use as a finder for star hopping and utilize my mounts tracking. Since the Nighthawk weighs 6.2lbs itself I'm a little worried about overtaxing the mount. Once you add a dovetail bar, clamps, and mounting rings it will add a little over 10lbs. I only plan on using this for visual observation and not imaging. I have a counterweight system which I can use to help balance the SCT to help relieve strain on the tracking motors but they would add even more weight.

So my question is ... Have any of you done this already?, Is it feasible?, and is there a lower weight way of mounting this that I'm missing?

Any info would be appreciated.

Fred

May 19, 2007 11:17 AM Forum: Eyepieces

Re: Is there a 4mm Univ. Optics HD ortho?

Posted By Fred Dase

As far as I know there has never been a 25, 5, or 4mm HD. But I've only been looking for the last year or so.
I've been told by a good authority that the HD Orthos are made in the same factory as the Baader line, but with slightly different coatings. Baader has the 5mm but no 25 or 4mm.

Fred

May 21, 2007 02:33 PM Forum: Equipment Talk

Meade LXD-75 tripod

Posted By Fred Dase

I'm considering purchasing this mount for my 80mm refractor. After reading reviews, most of which were a couple years old, I'm concerned about stability of the tripod.
I would be interested to hear from anyone who bought one within the last year as to their feelings on the subject. At this time I don't plan on doing any imaging, but would like to have that option open for the future.

Thanks ... Fred Dase

May 28, 2007 06:28 PM Forum: AstroMart FAQ

Marking a item sold

Posted By Fred Dase

I sold a item and when I went to edit my ad to say it had been sold I clicked the tab that says "Mark as Sold" instead of manually editing the ad as was my custom.
My entire ad disappeared. Is this the way its supposed to work ?

Fred

June 20, 2007 05:55 PM Forum: Equipment Talk

.965 compression ring adapter for 1.25" focuser

Posted By Fred Dase

Would anyone know where I could aquire one of these. The only one I can find online is for a specific Takahashi telescope. Theres no pictures of it so I can't exactly tell if it screws in or works with a standard diagonal. I assume it screws in.
Any help would be appreciated.
Thanks Fred

July 22, 2007 03:17 PM Forum: Star Parties

Almost Heaven Star Party

Posted By Fred Dase

August 9-12, 2007

The 2007 Almost Heaven Star party at beautiful Spruce Knob, West Virginia.
Held at the darkest site in the East, the AHSP has amenities, hot showers,
meal service, and internet access you won't find at any other star party.
Plus you'll enjoy daytime programs for the whole family like hiking, birding,
canoeing, caving, and mountain biking.

Sponsered by The Northern Virginia Astronomy Club

For more Information go to: http://www.novac.com/

September 1, 2007 07:03 PM Forum: Eyepieces

University 12.5mm Ortho Reticle Battery

Posted By Fred Dase

Does anyone know what battery this uses?

I recently bought this used University 12.5mm Ortho Reticle Eyepiece.
The seller had removed the battery, and is not responding to emails.
University Optics has not replied to my emails either.
There are no markings anywhere on this reqarding voltage or size.
I've had the illuminator to Radio Shack and Battery Mart and they have no idea.

Any help would be appreciated
Fred Dase