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About Merkhet

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  1. DRAKE NUMBER> The link in the original post takes you to The DRAKE Number, and then The Darke Number. For anyone interested in the DRAKE Number, there is a television program on BBC FOUR that explains the DRAKE Number. The program will be broadcast on 14th November at 1:30 in the morning. After it has been broadcast it will be available on the BBC iPlayer.
  2. I sure stirred up a hornets nest when I mentioned mirrors. I am glad though that the problem is getting a good airing and hopefully we can get to the bottom of the problem between us all. Cheers everyone.
  3. Stu and Littleguy80 I have my bottle in front of me and one line says....... cleans without scratching: eyepieces, objective lenses - even mirrors (please see separate instruction ! ) I didn't receive a separate instruction sheet, and looking at the new Baader website I cannot find any separate instructions for use with mirrors. Perhaps I should retract my statement about cleaning mirrors. I got away with using it on a mirror, but I would not like anyone to destroy their coatings. So best read the extra instructions before using it on a mirror. If any one has a copy of the extra instructions for mirror use, could they please put up a link to them or copy them out here before any damage is done. Thanks Stu for pointing that out.
  4. I find the Baader cloth and fluid are excellent. I cleaned a 12" mirror with the fluid and cloth . It came up superb. A warning though when using any lens fluid. Just dampen the cloth. You do not want any free fluid getting between the individual lenses of an eyepiece. When I had less experience and sense, I used a soaked lens tissue that was supplied in a sealed sachet. With hindsight I now realise that I should have squeezed out the excess fluid from the tissue. I didn't. The fluid seeped into the lens mount and between the uppermost pair of lenses in a microscope eyepiece I was cleaning. Th fluid either dissolved the cement holding the lenses together or seeped into the air gap. The result is a lens with a slight vignetting around the edge. If you are using it on a mirror you have nothing to worry about. But still be careful of your handling of the situation. Just think about what you are doing and you will have no problems. It's excellent stuff.
  5. Hello spikkyboy A word of warning to anyone in the UK. In the small print of the ebay advertisement it mentions customs will have to be paid. I know someone that purchased from China, via ebay, and had an unexpected bill from the UK Customs for the unpaid duty. They thought it was a scam at first , but it wasn't . They had not read the full advert. The bargain that they had bought was not such a bargain after all. Check out your own countries import duties before buying.
  6. I took a hacksaw to a very cheap engineers vernier protractor and after a bit of lathe work on some scraps of aluminium and the addition of a microscope measuring eyepiece, I ended up with a micrometer eyepiece that has a vernier protractor for measuring angles. I have seen a lot on the internet made with six inch plastic protractors. They seemed a bit big for my liking. The vernier protractor cost about 25 uk pounds on ebay and that compares well to some architects drawing, plastic protractors of around eighteen pounds! I thought long and hard before cutting the thing up. Worth it in the end. I have had this about a month now but no cloud free nights to try it out yet. Seems to work fine in the daylight though. The reason I wanted to put a measuring graticule in my telescope lens was so that I could convert the device to take a proper astronomical eyepiece. Some pictures of the microscope eyepiece version follow.
  7. Louis D might like to see the two eyepieces I was talking about. 7 and 20 mm Vixen Lanthanum. The views through the base of the lenses are 7 mm on the left and 20 mm on the right.
  8. Louis D You sure are on the ball with your brain power today. It works fine with the 20 mm but not the 7 mm eye piece. I had only tried the 20 mm until you threw some light on the subject. I held both up to a light and peered down them with an eye glass. the 7 mm is that small an aperture, I cannot see if there is a stop in there. The 20 mm when looked through from the the telescope side has a disc of light showing through of around 18 mm and no sign of a stop to my untrained eyes. They were bought at the end of 2000 . In the Vixen catalogue of the day .... code no. 3757 LV Series. LV20mm. AF 50 Degrees (W) 20 mm eye relief 142g. code no. 3864 '' LV7mm AF 45 Degrees '' 148g. "A high-grade optical glass Lanthanum Crown is used for their convex field lens. Fully mulyi-coated optics...." I found the receipt for the 70 mm bought around the same time. That was roughly £110.00p UK pounds. A lot of money to me in those days. I remember dithering about whether to get one or not. Money well spent in the end. I will get there by hook or by crook, but I wont be shelling out a wadge of money when I have the makings, tools and enthusiasm to adapt my gear accordingly. MarsG76 I saw them many years ago as a commercially made item, it could possibly have been something to do with photography. I cannot remember where I saw them. Thanks for the input so far everyone.
  9. That's correct MarsG76 . I want a filter holder that has no shoulder on it. Threaded the full length of the filter holder on the outside. So it can go right down into the eye piece and almost touch the lens. I have a few graticules from microscope eyepieces. i have dropped one into the telescope end of the Vixen eyepiece and it comes into focus perfectly. The graticules are various diameters and have a variety of scales on them. One has a 360 degree protractor engraved on it, I put that one away in a safe place but cannot remember where at the moment. One has a cross hair with micrometer scale on the horizontal and one has a grid of squares of about 18 squares by 18 , handy for drawing the Sun onto pre printed charts and one has a stand alone 180 degree protractor. I want to make an eyepiece similar to the Baader illuminated eyepiece people use for measuring double stars separation and angular distances. The illumination is easily sorted with a dimmable LED and a drill hole. Instead of paying out about 160 UK pounds I have the makings to hand apart from the fully threaded filter holder. If they are not made I shall do a work arond and make apush fit holder, as used in microscopes many years ago. Cheers for asking.
  10. I use Vixen Lanthanum eyepieces. The old style with parallel bodies. They have a filter thread size of roughly 29/30 mm. At the telescope end they are threaded the full length of the tube. I want to be able to screw a filter holder right down inside the mounting tube so that I can fit a measuring reticle to one of my eyepieces. Does any one know a make or supplier of filter holders that are threaded the full length of the outside of the holder, so they can screw right down inside the eyepiece? A UK supplier or the name of maker would be very welcome. Many thanks.
  11. Regardless of what you buy, micrometer or Vernier, cheap or top of the range. Do not lend it out. I have picked up micrometres in workshops that have been screwed up tight like a G clamp, straining the all important, accurate screw thread and actually saw a bloke prising off the lid off a pot of paint with some one elses Vernier calliper. Decent tools are well worth looking after. Sorry to be a killjoy.
  12. I have a Vixen Great Polaris GP-DX equatorial mount with the polar axis scope. This has a graticule calibrated up to the year 2010. As you can see from the accompanying photos various positions are used as time marches on. The problem is we are in 2017 and the scale only goes up to 2010. I have looked for graphs and charts displaying the differences between the Celestial North and Polaris so that I could predict future positions, but all to no avail. I was wondering if I just mentally extend the scale as shown in the accompanying picture would this actually give me an accurate point to align Polaris on? The drawings are taken from the Vixen Instruction Manual with my extended positions drawn in.
  13. There is a firm near Wigan called Leigh Bearings. It appears on the internet as Simply Bearings . If you click on their site Engineering Parts then Spring Steel Thrust Washers you find loads to choose from. 50mmm and 55mm i.d. are the closest to 2" . I have bought bearings from them over the internet a few time and they are reasonably priced and very fast with their deliveries. Even if you are already sorted, it is well worth having a look around their site if you cobble up your own equipment and gadgets as I do.
  14. A big thank you to the folk that sorted it out.
  15. Nice to see you are still in the land of the living Freff . Quite envious of your set up. I made a similar pier many years ago, but as there was no space for an observatory in the garden at the time so it is mounted in the garden path. The concrete block and base were cast and set in a deep hole in the garden path. The bolts for the base are about eight inches below ground level. When the pier is not required for a while , it is unbolted and removed and a 12" round, aluminium drain cover fits in place over the hole. I think an observatory is long overdue.
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