Dew Heater Tapes

[Freddie]

Hi, anyone got any hands on experince to suggest the best location for a dew heater tape on a CPC9.25 or similar? Is it best to put the tape around the metal ring at the end of the tube or just behind this ring and in contact with the tube itself? The metal ring is closer to the Corrector Plate but it's quite a big lump of metal to heat.Thanks Freddie

[brantuk]

I put mine just behind the metal ring and in contact with the tube itself. Then the dew shield goes over that (but anchored just behind the tape). Some use a second band at the back of the tube around the primary as well

[barkis]

The one I made for my Meade SCT, Is made from ring of the new type Central heating Pipe . The bore is large enough to take a ring of series wound resistors to give 15 watts at 12 volts this output is adjustable via a controller. The plastic tube loop is joined and cemented, with the supply cable connected to the resistors through a recess in the tube. The whole thing fits snugly inside the corrector housing, and buts up against the corrector retaining ring. It can't interfere with the Dew Shield when that is in place, and in no way interferes with the incoming light.

Ron.