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    Life, the universe, everything!?....
  • Location
    Wallingford, Oxfordshire
  1. Thanks Jetstream. Ill look into that. I guess its just a matter of letting the condensation escape while still keeping the dust out. Clive
  2. Thanks Dave.....not in the US but darkest rural Oxfordshire, England. I guess if i do have the mirrors recoated, then I'll have to think of a better way to store it. Maybe if I remove the dust cover while the temperature stabilises it will let any condensation escape? Clive
  3. Sounds promising....what is the quality like? Clive
  4. Thanks guys. Look into re coating on the not too distant future. Clive
  5. Its a closed tube skywatcher 12 inch dob John. Probably 7 to 10 years old? Its not bad enough to significantly effect the seeing though. Clive
  6. Hi guys Do mirrors fair better if kept in the house? I cleaned my mirror a few months back and it is starting to go milky already. I keep it in a dry shed outside. Many thanks Clive
  7. Thanks Moonshane, will do. I have a feeling that it may be down to the cradle not supporting the mirror equally. I'll reset everything to be on the safe side. Clive
  8. Sorry guys, my bad. I meant the secondary was glued in place. Doh! Clive
  9. You could well be right guys. As i mentioned, 3 of the adjustment screws have free play and one is at its stop. I will get the cell out, loosen all the screws and untighten the rubber mirror holders until there is a 1.0mm gap. Pretty sure it isnt the primary because thats stuck to the mirror holder with glue. Clive
  10. Thanks Ibbo! I'll check the primary 1st then turn my attentions to the secondary.....I will get to the bottom of this! Clive
  11. Thanks for the replies guys. I guess i unclamp then rotate the mirror and then reclamp? The irony was that even with this pinched pattern I had a fantastic session last night. M42 was beautifully wispy and detailed, and I could split the trapezium without to much fuss. Clive
  12. Thanks Peter, if it was the same would that imply damage to the mirror or something else? I suppose it cound be the secondary....to find i would have to slacken the 3 allen bolts back to their stops and re collimate. Clive
  13. Hi guys Got an opportunity to star test my Skywatcher 12" dob last night, having loosened the retaining lugs that were indicating a pinched optics pattern. I'd purchased a 5mm eyepiece specifically for this as the dob is an f5. So centered on a bright overhead star and it was still showing the flattened triangular sides??. I'd left the recommended fag paper thick gap between the reatainers and the mirror so I wonder if problem if the tension from the plates on which the mirror sits (one of the adjustment screws is at the end of its play and the other 2 are mid thread) can this pinch the optics? Just wondered if anybody else has a similar experience? Many thanks Clive
  14. Thanks John. I've got some good pointers from this post but if it continues I'll get a screen shot up. Clive
  15. It must be said that i didnt really give the scope much cool down time but i do have it in an out building. I did leave a tiny gap between the clamps and the primary mirror so i can only assume the problem lies with mis collimation, tube currents or a pinched secondary. I'll experiment with the 1st 2. Thanks for your advice Clive
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