Dew heater placement

[Lognic04]

Hi all, :hi:
'Nother question! If i wanted(need:lol:) to buy a dew heater for winter imaging, where would it go? I have heard that wrapping a single heater around the OTA from the legend Phil hart himself will be ideal for when i need primary and secondary heating because i can't install a primary fan?
Will a single heater around the tube be able to deliver enough power to heat the primary and secondary? My tak is a steel tube so no worries about heat transmission, however, i am also worried that the single heater may not be able to keep up with the large surface area tube.
Ideally a dew-not heater would be great, as they are quite inexpensive vs Kendrick.
:thanx:

[LewisM]

https://myastroshop.com.au/products/userselect.asp?Keyword=dew&SearchCat=Brand

I had 2 of these running all night off a clapped out old Supercheap Auto jump starter pack. Had them on the low setting. One behind the objective cell, one on the guidescope objective.

By 1am everything around was covered in ice and frost (lens caps, bahtinov, neoprene computer cover, rug I put the power cable on the ground etc. Not a zot of ice or dew on the glass or the tubes. NADA.

Cheap, and don't need a separate controller, as the controller is built into the cable - low, off or high. NEVER had to go high yet, and it was -4° last night.

[Lognic04]

Thanks, would like to know if a heater would work with my tube however :)

[glend]

What kind of scope is it? A single strap around the objective end of a refractor is usually all that is needed, but if a Newt invest in a secondary heater (they fog up first).

[LewisM]

It's a 160mm Newt.

[issdaol]

The Dew-not Straps and Controller are extremely well made.

All constructed by hand by the owner in USA as well.

They also have very low power draw when compared to Kendriks and other systems which is an important consideration on the operating time of your battery each observing session.

I have heard of others using kendriks and the cheap Chinese ones like Lewis with the inbuilt controller on the cable completely draining batteries in a single night out.

[LewisM]

Nope, they don't - that was a dodgy charger on the battery. I run it off my clapped out 8 year old Super Cheap jump start pack (yellow) - all night no issue. VERY low draw.