Hi Tim,
I have one of these heater bands around the collar of the corrector plate of my C11
RVO Heater Bands With Integrated Controller – Rother Valley Optics Ltd
and a dew shield (made from a black foam exercise mat) over the heater band and ‘scope tube.
Apart from a few nights during our glorious summer, the heater band is switched on before an observing session and kept running until close of play. No more misty optics…
Cheers,
Alex.