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Hi Joan,

Very impressive improvements. Congratulations!

Keep safe

François

Bonjour François,

There is still to do one test for to try improve of NOU_T results. I've bought an old Noct NIKKOR 58mm. f/1.2 with one aspheric lens, I hope it's going to improve the residual distortion and coma in the CCD image area.

This NIKON has come from Japan, unfortunely now it's in Madrid Customs, I've paid his taxes but wiht the current situation I don't know when will arrive this box at home.

Bien amicalement, Joan.

Hi,
Most of us know that is a "error" use photographic objectives in our spectrographs but most of us with conscience and obstinance, let's continue use these ones in our spectrographs and echelles.

The photographic objectives has been designed for meed the needs the complicated photography world. I only know two ways for don't use these ones.

The first, is bring our current echelle designs to resolutions about 20000, but that would limit the stellar magnitude range of our telescopes.

The second, is design and build of one specific objective for our echelle, but that collides frontally with my, ( our ? ), economy.

What rest to us.., the photographic objectives with all their loads of astigmatisms and comas.

I've fell again in the "error" and I've bought, ( with wife's permission ), an old Noct-NIKKON 58 mm. F1.2. And I show here the first results with daylight, I haven't tested it in the sky due the bad weather.

At difference of the 85mm. I haven't catched a compromise focus for one great range, if not, the best focus for the central spectra zones to be able to obtain the best resolution. If I had wanted the best focus with the 85mm., sure I had obtained one R around 11000.

Now with the new NOU_58, the R is nearly 9000, with halve integration's time tham the 85 mm.

If I changed the pinhole of 50 microns for one of 40 mm., sure that the R could to increase around to 10000 or a bit more, but it represent increase 30% the current integration time.

J. Guarro.

Hi,
In these unfortunate lockdown days with bad weather and without any spectrographyc observation, I've spent some time drawing a new version of NOU_T spectrograph with it main characteristic is the change the equilateral prism F2 for a transmission grating of 300 l/mm.

The echelle orders across transmission grating have some differences than an equatorial prism, in this case the orders are practically straights with more, ( apparent ? ), definition. Another singularity. Another difference is their order separation increment is inverse, in other words, in transmission gratings the infrared orders are more separed than de violet ones.

The set of all ordres in the same contitions, in the same photographic objective are also more separed in a transmission grating 300 l/mm. than an equilateral prism F2, so, if it don't have any surprise, should alow detected more easily his more closed together orders.
At the moment, in my lockdown, I make, with hand tools, two prototype of it al home, on the next days I'll be able to show you some pictures of their mechanical parts.

On the other hand, there's not very complicated, it's easy, adapt to the boxes of NOU_T and also to NOU_X, one optical fiber system, there are some advantages in it, how carry less weight in the equatorial mount, that is a better use and performance for it and better thermal stability for the optical box in hard climatics conditions in places where on the thermal fall are very dramatic.

J.Guarro.

Hello at all,
I hope that the weather will change soon, because here until today,  this year is not very good for astronomical observations.

In this lockdown time I have improved the Relco and Tungsten lights, changing the old capacitor lens for an 30mm. eyepiece plössl,  the result has been excellent.

Another improvement in the NOU_T has been the tilting of 1,5º  the ATIK460EX as C.Buil explains here, http://www.astrosurf.com/buil/us/spa/test.htm.

I am very glad with this spectrograph, due at the weather I only have tested currently with HD103287.

You be able to see here the orders detected and their R. Of course, you may improve the Resolution in the Orders 25 to 29, with focusing them but that is  detriment of the others ones.

By the way, a R = 8000 in the Order 56 it is good, or not ?


  Resolution :
Order #25 :  FWHM = 5.91  -  Dispersion = .271 A/pixel  -  R = 5529.8
Order #26 :  FWHM = 6.85  -  Dispersion = .247 A/pixel  -  R = 5040.7
Order #27 :  FWHM = 6.31  -  Dispersion = .242 A/pixel  -  R = 5372.3
Order #28 :  FWHM = 6.37  -  Dispersion = .221 A/pixel  -  R = 5601.7
Order #29 :  FWHM = 5.74  -  Dispersion = .227 A/pixel  -  R = 5841.7
Order #30 :  FWHM = 4.06  -  Dispersion = .219 A/pixel  -  R = 8299.1
Order #31 :  FWHM = 3.63  -  Dispersion = .209 A/pixel  -  R = 9409.0
Order #32 :  FWHM = 3.43  -  Dispersion = .196 A/pixel  -  R = 10273.8
Order #33 :  FWHM = 3.42  -  Dispersion = .202 A/pixel  -  R = 9734.4
Order #34 :  FWHM = 3.59  -  Dispersion = .193 A/pixel  -  R = 9378.5
Order #35 :  FWHM = 3.32  -  Dispersion = .188 A/pixel  -  R = 10108.2
Order #36 :  FWHM = 3.43  -  Dispersion = .184 A/pixel  -  R = 9734.5
Order #37 :  FWHM = 3.51  -  Dispersion = .179 A/pixel  -  R = 9548.5
Order #38 :  FWHM = 3.89  -  Dispersion = .171 A/pixel  -  R = 8771.1
Order #39 :  FWHM = 3.69  -  Dispersion = .171 A/pixel  -  R = 9007.9
Order #40 :  FWHM = 3.56  -  Dispersion = .166 A/pixel  -  R = 9343.5
Order #41 :  FWHM = 3.78  -  Dispersion = .157 A/pixel  -  R = 9111.5
Order #42 :  FWHM = 3.80  -  Dispersion = .157 A/pixel  -  R = 8817.6
Order #43 :  FWHM = 3.75  -  Dispersion = .155 A/pixel  -  R = 8842.5
Order #44 :  FWHM = 3.60  -  Dispersion = .152 A/pixel  -  R = 9217.0
Order #45 :  FWHM = 3.89  -  Dispersion = .148 A/pixel  -  R = 8542.6
Order #46 :  FWHM = 3.83  -  Dispersion = .143 A/pixel  -  R = 8758.4
Order #47 :  FWHM = 3.39  -  Dispersion = .139 A/pixel  -  R = 9964.4
Order #48 :  FWHM = 3.48  -  Dispersion = .140 A/pixel  -  R = 9444.8
Order #49 :  FWHM = 3.32  -  Dispersion = .137 A/pixel  -  R = 9954.6
Order #50 :  FWHM = 3.29  -  Dispersion = .134 A/pixel  -  R = 10054.9
Order #51 :  FWHM = 3.23  -  Dispersion = .133 A/pixel  -  R = 10138.4
Order #52 :  FWHM = 3.10  -  Dispersion = .127 A/pixel  -  R = 10782.3
Order #53 :  FWHM = 3.30  -  Dispersion = .124 A/pixel  -  R = 10196.6
Order #54 :  FWHM = 3.58  -  Dispersion = .123 A/pixel  -  R = 9288.0
Order #55 :  FWHM = 3.68  -  Dispersion = .121 A/pixel  -  R = 9060.9
Order #56 :  FWHM = 4.31  -  Dispersion = .116 A/pixel  -  R = 7923.6  

Greetings, J. Guarro.

Hello all,

The philosophy and also one of the motives about build five new NOU_T mechanical parts is be able to put this type of spectrographs within reach to some observers, that just like me, can not  afford to buy a commercial echelle.

So for this motive, I don't want to compete in any commercial business, that is not my intention. The NOU_T echelle would be for observers that wouldn't  be able to ever buy a commercial echelle, so I'm not ruining anyone's life.
On the other hand, I think the pricing policy of the commercial houses is totally fair and justifiable. also we mustn't forget the great help that  some of they have done  and are doing to amateur spectroscopy.

The next step is anodize the aluminium pieces I don't know how time I will have wait for it.

If some of you are really interested in this project and if you would like get one NOU_T, please let me a private message in that Forum.

Cheers, J. Guarro.

Hello all,

For your information the weight of this NOU_T mechanical part is 1760 grams now.

I think is possible remove some weight without lose stability and strength.

It ideal weight would be 1500 grams. now.

Cheers, J.Guarro.

Hello Joan,

It's a very nice proposal and a great spirit of sharing.

Cheers,

Benji

Bonjour Benji,

Many thanks for your short comment.

How many hours are you bring working with the AudeLa ? Why your effort in it ? Many thanks to you for it !
It's the same sense than other cases that you can see here.

The NOU_T is working very well with Piera telescope and I'm making these 5 ones of them now, because I need one of them for the SMM telescope. At the same time, I'm making 4 more NOU_T, I don't know if someone will want one of them, if not..

Bien amicalement, Joan.

Hello to all,

Finally I be able to show two pictures of the NOU_T mechanical parts finished.

The next step is save money, buy the optical elements and mount them, I hope will have finish this NOU_T in the last days in that year.

Remember there are four for who want one of them, it cost is really affordable.

Greetings, J. Guarro.