64 replies to this topic

[Astrobril]

I have them both: the Unitron 142 (Polarex 131) and the Royal Astro 76.2.

Well, the RA kicks ****...never seen bettter contrast in a refractor in 40 years of observing.

Don't underestimate the Unitron; it's good,  very good actually. But my RAO 76.2 is optically  in an entirely different league.

So, the Royal Astro is now on the Unitron mount - it's the best of both worlds.

Amazing.....

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[starman876]

Has this scope killed anything else 

[scopelover]

I understand your excitement about RA 76mm/15 scopes !!!

........ The majority of them indeed have Killer optics

[Don Taylor]

I have an RAO 76.2 x 1200 as well - converted to 1.25" drawtube.  The optics indeed are outstanding!  I have no F15-16 Unitron to compare to but it is sharper and with less CA (as would be expected) than my 800mm F11 Astro-Physics guidescope (made by Nihon-Seiko, manufacturer of Unitron). Mine lives on an old style Vixen Polaris and custom tall wood tripod.  

 

Yes, great scopes.

 

Edited by Don Taylor, 22 September 2019 - 06:37 PM.

[RalphMeisterTigerMan]

In his youth, Toronto Astronomer Terrance Dickinson was using a Unitron 3-inch for observing the Moon. At the same time, the USAF recruited several amateurs to create a map of the Moon which could be used for the Apollo Moon landing program.

 

One of the features on the published map was shown incorrectly. Terrance had observed this feature many times (it's name escapes me at the moment, It is mentioned in his book Amateur Astronomy) and was positive what it actually was. Not bad, considering the Moon Mapers were using the 24-inch refractor at Lowell observatory and Terrance's scope was only 3-inches!

 

Clear Skies!

RalphMeisterTigerMan

[Tenacious]

Sadly, I've never had the privilege of looking through a Unitron, nor even at one in person.   Still, the Unitron photo/equatorials inspire some of my rescue/mods.

 

My Royal Astro 10TE-5 rescue scope never disappoints optically.  At f/15.7, even my inexpensive or wide-angle 1.25" EPs present wonderful images of the planets.   The original mount takes some special handling (with or without my extra payloads) to compensate for minor instability, but this isn't too difficult to live with.  OTOH, if I had a Unitron mount, or a Vixen Polaris, I would try the 10TE on it, too.

 

Don, did you ever compare the Polaris to the original mount?

 

Edited by Tenacious, 22 September 2019 - 08:52 PM.

[ccwemyss]

The three RAO (AOC) scopes in the loaner set (2 10TEs, Mayflower 816) all deliver excellent images, with only the 80mm HOC ATCO 1254 being a bit better. None of the mounts are anywhere near as stable and smooth as the Unitron 142 though. There's one for sale on AM for $650 now. The 76mm OTAs just need some extra spacers to ride in the Unitron rings.

 

https://astromart.co...and-tray-462985

 

Chip W. 

Edited by ccwemyss, 22 September 2019 - 08:58 PM.

[Bomber Bob]

Here's my Unitron 142 vs. Sears Model 6336 test thread:  https://www.cloudyni...l-at-the-swamp/  

 

Both fracs had qualities / traits that I liked.  The Royal resolved the tiniest details that eluded the Unitron, but it was the 6336 that I tried to sell first.

Edited by Bomber Bob, 22 September 2019 - 09:11 PM.

[Russell Smith]

Both great instruments I feel.

I'm still quite new to this but so far my best planetary views have been with the RAO.

However I need to spend much more time observing before my observations are of much value. 

 

I did put the tasco on a Polaris mount but if I don't want to sit on the ground (or worse) it needs longer legs. My example of the Tasco is IMHO beautiful to look at and use until it gets a bit windy. 

 

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[Russell Smith]

B.B.

That was a fun thread.

[photiost]

I have three RAO 76.2mm refractors and they are excellent .

 

I think this speaks volumes on the RA Quality control.

 

One actually resides on the Celestron CG4 mount which is motorized and this setup is often used for Public outreach.

 

Simply Amazing instruments !!

[Don Taylor]

Don, did you ever compare the Polaris to the original mount?

 

DSC05025.JPG

No - I acquired only an OTA. I thought about trying to find the appropriate mount but hard to come by at the time - so for a while I used the scope on a modern Vixen GP2 with single axis drive but eventually came across a Polaris (head only) and built some legs and spreader. I still need to finish the legs. Lots of sanding yet to do. The Polaris is very stable and the tall legs let me view zenith while seated.

[Don Taylor]

I have three RAO 76.2mm refractors and they are excellent .

 

I think this speaks volumes on the RA Quality control.

 

One actually resides on the Celestron CG4 mount which is motorized and this setup is often used for Public outreach.

 

Simply Amazing instruments !!

I agree completely.  Using the RAO on a modern mount like a CG-4 (or the GP2 i used) is splendid. Very stable, nice to have tracking too.  (click on each photo if you want it larger)

Edited by Don Taylor, 22 September 2019 - 10:37 PM.

[agmoonsolns]

I have been really impressed with every RAO I have tried and the 76mm/1200mm is one of my absolute most favorite vintage scopes. I am afraid I stopped collecting Unitrons once I started comparing them to the RAOs and the Goto refractors which are just simply that little bit better. The RAOs have uniformly very high quality lenses, I have never seen one with a bad lens. Unitrons do have nicer mounts though, kind of like functioning works of art. If one can put a really good RAO on a Unitron mount, that's ideal.

[agmoonsolns]

Don, your tripod is gorgeous! Did you make or buy it? Could you pretty please tell us more about it? It's one of the nicest tripods I have seen.

 

I have an RAO 76.2 x 1200 as well - converted to 1.25" drawtube.  The optics indeed are outstanding!  I have no F15-16 Unitron to compare to but it is sharper and with less CA (as would be expected) than my 800mm F11 Astro-Physics guidescope (made by Nihon-Seiko, manufacturer of Unitron). Mine lives on an old style Vixen Polaris and custom tall wood tripod.  

 

Yes, great scopes.

 

[Bonco2]

Just from what I've read over the years, it appears  optical quality control for the RAO is more consistent than Unitron. The original lens in my 142 Unitron was good but not fantastic. So I searched for a replacement lens and found one here on CN. The replacement lens changed the scope to about the best optics I've ever used. This tells suggest to me that Unitron's vary more than RAO. But I'm sure  many Unitron owners have scopes equal to  RAO's.

 

As noted tho the Unitron model 142 mount is a pleasure to use and look at. One other note: I replaced a Towa 80mm f/15 and a Tasco 10K 80mm f/15 lens with  Carton lenses from Sheldon....Whoa, talk about an improvement, close to perfection for a small achro. Lot's of good classic stuff out there. BTW the Japanese 80mm's fit perfectly in the 142 yoke.

Bill

[Chuck Hards]

I went through four 60mm Unitrons before I found one that was as good as any of my 60mm RAO scopes picked at random.   I've been a believer for a while now.   

[Steve Allison]

My Sears 6345 gives me a generous 90 mm of F/15.6 RAO goodness and looks mighty impressive all set up in my family room. The numerous prior threads regarding this top-flight achromat all point to the remarkable consistency among examples. One especially enthusiastic poster believed the RAO objective was superior to any Unitron 4 inch, even the earlier, more desirable Unitron objectives.

 

My Sears even holds its own against my excellent Tinsley 4 inch achromatic refractor, although I have never done a careful side-by-side. My Takahashi FS-102 NSV Apo obviously has better color correction, but the views through my RAO are not so inferior as to leave me despondent. This demonstrates to me the importance of excellent spherical correction and smoothness of figure.

 

Gotta love the RAO optics.

 

Steve

 

P.S.- Even the little RAO 40 mm guide scope on the big achro is an excellent telescope in its own right!

Edited by Steve Allison, 24 September 2019 - 12:24 AM.

[Don Taylor]

Don, your tripod is gorgeous! Did you make or buy it? Could you pretty please tell us more about it? It's one of the nicest tripods I have seen.

Thank you. 

 

I built the legs about 7 or 8 years ago and just now am getting around to finishing it. I have been using it though. The legs are an H of red oak rails and the web is (If I recall - stained poplar) the rails are glued and screwed to the webs with flush brass screws. The bottom of the legs are pulled together. The spreader is plywood and tightly couples to the legs. The lazy-susan (who came up with that name?) eyepiece tray runs of felt pads so it's not free spinning.

 

I posted some photos in another thread a few months ago and received a lot of encouragement for finishing the tripod. I have started sanding on it again. Need to apply some wipe on poly. The eyepiece lazy susan is finished and much darker than in the photos.  Below are a couple of pics taken when I first built the legs - a trial assembly.  Looks much better now.  Measuring straight down from the top of the legs (with the tripod set up) is 57" (1.45M) so it's rather tall.

 

Hopefully I'll get it finished soon and take some much better photos.

 

You can click on the photos and a larger view should pop up. 

 

[Bomber Bob]

The RAO 40x500 "guidescopes" are also excellent for their aperture.

 

Wish we knew where Royal sourced their objectives.  We might find that multiple makers were used, depending on the model, year, etc.  (After my own testing of the Old Towa 60x800 refractors -- those with no maker's marks -- I've wondered if Towa used the same companies as Royal during the 1950s & early 1960s.)

 

Here's some DPAC patterns for my Lafayette Galactic, a Royal "DuoScope" with a 76x910 + 40x500:

 

 

 

These patterns are only slightly less impressive than my 80mm & 50mm fluorite APOs.

Edited by Bomber Bob, 23 September 2019 - 08:29 PM.

[Barnsey123]

Sorry to revive an old thread but I have the opportunity to purchase an RAO 76.2 x 1200 (converted to 1.25" drawtube) in UK.

My current scope is an Altair 102ED F7 sitting on a HEQ5/Pro mount.

 

I'm considering getting a reducer for the Altair and using that primarily for DSO work and was debating getting a SW MAK 150  for planetary/lunar and then the RAO came along. Now I'm torn.

 

Compared to a modern day ED scope (not APO) how do the RAO's measure up (would put it on the HEQ5)

 

Would appreciate any guidance here (only been doing astronomy this year really so I'm still at the bottom of a very steep mountain)

 

Thanks

Neil.

[oldmanastro]

I have owned a 76.2mm f/16 RAO for years and it has never let me down. Optics are downright excellent. Now I have another one. A Sears 6336 pedestal mounted 76mm f/16 RAO. The optics are just as good.  I cannot say anything about Unitrons since I have never seen or touched one. It's nice to know that the RAOs can go one on one with the Unitrons.

 

 

Guido

[PawPaw]

There is a archived thread that discusses who supplied the lens to Royal Astro.   One of our Japanese brethren "Galakuma" talks about his recollections on the source of these  objectives.   As with all of the vintage objectives your mileage my vary!

 

https://www.cloudyni...s/?hl=mark goto

 

Here is a snippet from one of his posts:

 

I’ve heard below.
1955. Trouble broke out in Goto optics, Mr. Horiguchi and Mr. Kojima retired.
Mr. Horiguchi who was an excellent lens designer founded the Horiguchi optics.
Mr. Kojima who was an excellent mechanical designer founded the ASTRO optics.

Mr. Horiguchi supplied to Astro, Goto, Takahashi and other.
I don't all or not to their.
I don't know to Nikon, Unitron.

Mr. Horiguchi gave up at the end the super-apochromat for MARK-X of Goto optics and semi-apochromat for Takahashi, before fluolite-age.
I think that another lens designer was in Nikon.

 

 

The Horiguchi optics supplied the object lens of the high quality almost of a famous manufacturer(Swift, Astro, Vixen, EIKOW .etc.) until the first half of the 1980's.

I think that SATMAN's Mayflower 76mm Royal Astro use objective lens of Horiguchi optics.

[Bomber Bob]

Compared to a modern day ED scope (not APO) how do the RAO's measure up (would put it on the HEQ5)

 

The RAO will show you everything a high-quality 3" F16 achromatic refractor is capable of.  My 1964 model out-resolved a China-made 80mm F6 ED triplet at 200x & above, with minimal CA (visible only on the brightest objects).  The size & weight are easy to deal with, too.  They are Classics.  If you don't have a LONG vintage small achromatic, you should at least try one -- see for yourself.

[Chuck Hards]

Besting a Unitron optically isn't a Herculean task.  I've tested 11 on the optical bench and I only consider one "outstanding".   I have never been disappointed in anything carrying a RAO maker's mark.

 

Amazed even myself, I wasn't happy when my Unitron bubble burst, but it is what it is.    Imagine waiting a lifetime to own a particular scope only to discover once you get it that it's nothing special, and that Tasco in the corner is optically much, much better. 

 

That said, I'm keeping the 128 that I got from Al, via Johann.  It is the equal of any RAO lens of similar aperture, but it's the exception from my experience.