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Unitron / Polarex direct-drive motor system for Japan '50s - One-Off Prototype?

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#1 C8 Ronald

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Posted Yesterday, 06:23 AM

Recently discovered a very interesting topic on the Unitron/Polarex facebook-page:  https://www.facebook...11333119105234/

 

Discussed is a very rare (probably a one-off) direct drive motor system on a Polarex 60/900mm Equatorial mount.

 

It was, given the displayed power (100 volts), a system for Japan only, as in the '50s Japan had a 100 Volts grid.

 

I've never ever seen a drive system like this, so this is ultra rare indeed!

 

Somehow I can't link direct to the post, but all the details are in the facebook page topic.

 

Including excellent detailed pictures.

 

Has anyone here ever seen this before?  Perhaps on the bigger models aswell?

 

I've never seen any (brochure) documentation about it, but perhaps some Unitron/Polarex experts here can shed some more light on this?

 

Much appreciated.

 

Its surprising how many unearthed details, accessoires, interesting facts and discoveries still surface from time to time....


Edited by C8 Ronald, Yesterday, 06:24 AM.

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#2 C8 Ronald

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Posted Yesterday, 01:17 PM

Well, with a bit of Google searching this mistery is solved!!

 

Apparently not a one-off prototype!!

 

Discovered an older posting on CN (2008)  https://www.cloudyni...ex-24-eq-drive/

 

Posting contains much more information and pictures. Seems these alternative drives could be ordered in Holland in the late '50s.

Telescope type even had additional model codes: Model 2-PSE and Model 3-PSE.

 

Wow, very interesting stuff!!

 

The only thing I'm wondering about is the mentioned difference in mounts. I assume telescopes and mounts sold in Holland came right out of the factory in Japan. Clearly the mounts were probably not re-engineered in Holland, specially applicable to Model 3-PSE (with the moved R.A. setting circle).

 

The mentioned shop in the brochure/advertisement I know well, it was later called Polaris Optische Instrumenten on the same address.

Shop was a big word, telescopes were sold from a converted garage adjecent to the owners home....

 

Later this shop moved to Utrecht and eventually closed many years ago.



#3 Terra Nova

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Posted Yesterday, 02:26 PM

Wow! That one is new to me. Never seen it before!



#4 C8 Ronald

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Posted Yesterday, 02:38 PM

Yes Terra, I was so thrilled to have discovered it.

 

It seems (but not confirmed) that it was some sort of special package for the Netherlands only.

Never seen it advertised anywhere else.  And never seen one in the flesh, although I'm from the Netherlands myself.

 

Given the motor voltage had to be converted from 100 Volts (Japan) to 220 Volts (Netherlands), I assume the package might also haven been sold in Japan as such.

 

It was only offered for about 3 years, so these Model 2-PSE and 3-PSE scopes must be ultra, ultra rare now!

From 1961 onward the regular motor drives we all know were offered.

 

Wonder what happened to the scope and if the topic starter from 2008 still owns it.

I've sent a PM......


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#5 Bonco2

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Posted Yesterday, 03:20 PM

One of the weaknesses of the "normal" Unitron electric drives is the drive gets in the way at certain pointing angles. This unique drive solves that problem.

Bill


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#6 Spectral Joe

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Posted Yesterday, 07:20 PM


It was, given the displayed power (100 volts), a system for Japan only, as in the '50s Japan had a 100 Volts grid.

Since the dawn of electrification Japan has had a split system, 50hz in the eastern half and Hokkaido and 60hz in the west. Things like tape recorders and phonographs sold for the Japanese market had a means of adapting for either area, mechanically in the old days and probably electronic now. It's still 100 volts now.

Edited by Spectral Joe, Yesterday, 07:22 PM.

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