I have now used my new USB dew heater out in the cold night several times. Many positive things, I can reduce the power a lot. From my earlier dew heaters at 5.6 Watt I can now go as low as 1 Watt for both. Important when out on the fields and on battery.
Photos and text:
http://www.astrofriend.eu/astronomy/...ting-band.html
/Lars