01.02.2021 Icy cold!

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Monday 1st February. 32F. Sunny periods after a cloudy start. Signs that small birds have been roosting in the observatory.

I completed the rear, worm bearing brace but now I am struggling with too much friction on slews. Which doesn't make sense because I have ready slacked off the bearing pre-load screws. 

Tuesday 2nd. 10.45  -8C, 17F, Mount and scopes frosted all over! Cables stiff. Trying to image but the objective is dewed up again. Dew heaters on. A blast from the hairdrier helped on the D-ERF.

RA drive stalling on slew but tracking well. I must attend to that. Removed the screws and bearing brace for only slight improvement. Telescopes seem well balanced.

Removed the D-ERF to warm the dewed objective. Held the D-ERF in front to avoid cooking anything with unfiltered heat. Internal dewing doesn't react to the hair drier. Dew heater has reached 75F. I really do need to make a seriously insulating muff for the front end. I am losing imaging time to dew.

11.40 31/29F I can see two small dark sunspots. Nearing western limb. 1/3rd solar disk from the pole.

12.05 33/30F. Dew spot inside objective finally shrinking.

12.50 35/30F Have been trying to capture the spots in H-a and white light without success. Seeing too soft and won't support Barlows. Cloud has intervened. It must be lunch time!

The afternoon was no better so I tidied up. Then turned the dome to face the shutters to the east. A week of snow is forecast with easterly gales at times. Which suggests spindrift inside the dome and drifting elsewhere. I have covered the telescopes with a huge poly bag to try to protect them as much as possible. 

I should have bought a dedicated [middle-weight] tarpaulin ages ago. The lightweight ones are garbage. The "proper" PVC tarpaulins are far too heavy and far too stiff to fold up [cold] when not in use. Trying to manage one from a stepladder after a frost is too ungainly. I have tried covering the telescopes with my 350g/m² car trailer tarpaulin.

There is a midway selection provided they are not subject to too much UV or flexing wind. Unlikely inside a dome. Unfortunately most tarpaulins are supplied in unhelpful sizes for horizontal telescope covers. It would probably mean cutting a standard one in half and fitting new eyelets. I have tried spring clamps for holding them in place but they are not ideal. Perhaps I should try a lightweight scooter or motorcycle cover? They sell for as little as £10 equivalent and are not all oddly shaped for raised handlebars. It is not as if it will be subject to normal outdoor weather stresses.

 

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