Quote:
Originally Posted by Jazza
One quick question, do most of you leave the fan on all night or just run it for the first hour or so?
|
Jazza, what I read suggests that a couple of hours of fan is all you need to get the mirror temperature sufficiently close to ambient for the "less-than-really-fussy" observer, but I guess that depends on how far the temperature is dropping as the evening deepens.
For a solid tube OTA, many suggest leaving the fan as an aid in preventing dew formation on the primary and secondary mirrors. As long as the fan is not giving you unacceptable vibration of the image (easily checked) and you have the power supply, you may benefit from leaving it on (cooling plus dew reduction). Fan life (measured in observing sessions) would be reduced, but probably it'll outlive your ownership of the scope! The only other issues then are power supply and not getting tangled up in the wires.