First light with Unitron 4" 152

Started by fblue, 03/28/2010 06:22PM
Posted 03/28/2010 06:22PM Opening Post
Well, after getting the Astronomy Shoppe RA drive installed, I took the old Unitron to the back yard, light polution, Moon and all to see how it worked.

First, the RA drive worked well, keeping it on target for a long time, nice addition.
Then, polar alignment, well I guess I got it close, but still working on that one, no polar scope.

Checked out the Trapezium and got 4 stars, possibly 5, and some nebulosity.

Looked at Mars, not much to see, pretty small and seeing was less than perfect.

Looked through all the Unitron EPs, 40mm, 25mm, 18mm, 12.5mm, 9mm, 6mm and they were OK, but not the best really.

The Unihex worked fine, but I could not get a 45° upright 1.25" diagonal to come to focus, which I wanted to use. But I will get a 90° and make a new tube for the focuser so that I can get it in far enough, lacked back focus with the extension tube required for using EPs without the Unihex. Some better .965" EPs would be nice, but a good 1.25" diagonal would be more useful in some ways, or a 1.25" Unihex would be great!

Looked at the Moon to see how much power I could use and to see if it had a clean limb to check the color correction. Well that was a surprise! I got out the TMB Planetary EPs and was able to use a 4mm @ 382x or 95-96x per inch with good sharp image. Did not try any more power, thought that it would start to lose it for sure if I went to 3mm for 510x (127x per inch). I was quite impressed with how sharp the craters and ridges were in the EP. Tracking made it easy to study the details. Could not really see any color on the limb, pretty nice!

The mount worked well, the finder scope was a bit awkward, but I now see why they show the scope upside down in some ads. May try that next time. It required using my left eye West of the meridian. But, that was a minor issue.

Over all the scope and mount were quite nice and I am pleased with the performance, look and feel of it. grin

Attached Image:

fblue's attachment for post 50555

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager
Posted 03/28/2010 07:41PM #1
Nice report! Mine has done very well on Mars
-- not much blue or violet light to get in the way --
try that again with your TMB Monos.

The old Unitron eyepieces are certainly the weak part of the
system, in my experience. Don't need Naglers at F/15,
but some modern Orthos or Wide Fields with multicoating
will help.

I've often felt the Unihex was more of a show piece than
anything practical. Why have all your eyepieces hanging out
there gathering dust and dew? I'd try to find a 1.25"
diagonal you can use with it.
Posted 03/28/2010 10:03PM #2
grin Great report Floyd, glad you are pleased and very informative. Remember in old stuff like old cars we thought fm radio was the nuts..if you had air conditioning and power windows you where something..still good too have the old eyepieces with your vintage scope..john

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