Dew Control - Recommendations?

[Jbro1985]

Hi all,

I'm looking for dew control recommendations... 

Price is not necessarily important (no observatory suggestions though please!).  I am also wondering how, in principal, they work (I understand the physics) - but does one have a temperature sensor and so only starts to heat within set parameters of the dew point, or does one just turn it on and maintain a set temperature throughout?  Where precisely to you put them (I'm using a doublet refractor)?  What about filters (I used an enclosed electronic filter wheel but I'm pretty sure it isn't air tight)?  

Has anyone bought the dew heater for the ASI1600mm-c and does it work?

I know dew is going to crop up and its one of the few things beyond user error and clouds that would frustrate a session now so I am keen to mitigate.

Thanks in advance for any suggestions, recommendations or wisdom imparted.

Jason

[souls33k3r]

If you're looking to automate your dew heaters then  you'll need something like (and not limited to) "Pegasus Pocket Powerbox" (there are others available for different price and different manufacturers). These come with temperature sensors and you just let the sensor calculate the dew point and your dew heater straps will adjust accordingly.

If you go with something like (again not limited to) Hitecastro 4 Channel Dew Controller, you can only dial the temperature control manually by turning the knobs. 

If you go with the manual version, i start with about 1/4th of the way and then gradually increase throughout the night depending upon how severe the dew is.

As for the placement, i place one dew heater strap at the front lens of a refractor or at a corrector plate of my SCT, the other one on my guidescope (again at the front lens).

Hope this helps.

[Jbro1985]

OK.

Just to be clear, I would be amiss to just crank a manual dew control up at the start of the night, so it is heating above the dew point all night, enabling me to go to bed?