[gregbradley]

I am finding now the weather is cooling off at night the occassional bit of dew on my secondary on my CDK17.

What dew heating options are good? I have never used a dew heater before.

My APOs don't seem to suffer from dew much. I did get a bit of dew on an FS152 but I got this insulation blanket you wrap around the tube where the lens cell is and it kept the lens a few degrees warmer than ambient and stopped dew. It worked really well. You could make one yourself with some windscreen heat savers - you know the ones with silver foil insulation blanket you put on your windscreen to protect your dash? Use a bit of Velcro so it can attach to itself after you wrap it around the OTA where the lens is.

Greg.