Wednesday, 1 June 2016

Part 2 of my "How dew you dew" action for the Free State Star Party 3 - 5 June 2016


How to fight the dew from the top?  Start a fan club.

Will it work? Maybe to much vibration?  Will find out soon.

Heatwaves in the tube? Is "bad seeing" not better than "no seeing" at all? 

 It is a small 60mm fan right behind the secondary mirror. I plan to add an on/off switch and a variable resistor to bring down the speed or turn it off if there is to much vibration.

Dew on the secondary mirror was a bigger problem then dew on the primary mirror,  during the previous star party (2015).

And the white wiring?  That is a nichrome heater (harvested from an old electric blanket)  to heat up the air a wee bit. Maybe some airflow (fan) will do the trick.

* Plan B is to  mount the fan on the edge of the scope tube and point it in the direction of the secondary mirror. What next?

Some links with more ideas

Tuesday, 31 May 2016

Part 1 of my "How dew you dew" action for the Free State Star Party 3 - 5 June 2016

Dealing with dew at the Free State Star Party.
Maybe it will help. Some amateur astronomers are skeptical (3rd link). Maybe  a disk at the back to force more air onto the mirror as suggested by the author..

 Will use the fan  in combination  with heater made from nichrome wire (old electric blanket).
- Eyepiece area
- Secondary mirror

I will give feedback after the weekend.

Hannes Pieterse

Some links to helpfull web sites:
Using fans with Newtonian telescopes

Attaching a Cooling Fan to Newtonian Telescope

A simple telescope fan installation