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I know this sounds counter-intuitive after all the hype about thermal equilibrium, but please bear with me on this as I have had two similar scopes and my current one is a considerably bigger mak.
Insulating the OTA works wonders for killing the internal tube current, and it ensures the corrector won't dew over, either. Find a sheet of foam plastic or rubber a few mm thick - a yoga mat works well - and cut a piece big enough to go round the OTA and cover the OTA from end to end and then some - a short dewcap. Make some cutouts for the dovetail and finderscope. Wrap this reasonably tightly around the OTA - anything will do - adhesive tape, even your belt... I use a pair of velcro straps.
The point is that the internal tube current is caused by the thermal gradient within the OTA - ie the difference in temperature between the internal central baffle, and the air near the wall of the OTA (which is metal).
Ordinarily the night air is much cooler than the innards of the scope, so the wall of a bare OTA is chilled and a significant difference is formed, which drives the tube current. Note also that in the Skywatcher maks the primary mirror is supported on the central baffle and this amounts to a large thermal mass which continues to pour heat into the baffle for ages, as it has no other way to cool apart from convection.
Insulating the OTA stop it cooling, and hence the OTA stays at much the same temperature as the air inside and the baffle, hence no thermal gradient, and no tube current.
With the insulation, the main way heat escapes is then through the corrector plate, and its enough to keep the corrector plate warm and stop it dewing over, for hours.
It also means you won't need a heater strap.
There's another reason to extend the insulation beyond the OTA, as well - this makes a significant improvement in stray light baffling for maks, and the contrast on extended DSO's should be noticeably improved.
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