I just picked up an older Celestron 11" SCT OTA, its the model with the flat back (photo attached) and I'm wondering if the Celestron Dew Heater ring could be made to work on this OTA. I do not know when my OTA was made, but Celestron tech support says based on the photo that its not compatible but did not supply a reason (FYI that was the same story I was told about the Celestron Focus motor and all that I needed for a retrofit was to 3-D print a 15mm long tube with an ID of 19mm and an OD of 21.5mm to insert around the focuser and inside the focus motor). Both the dew heater ring and the OTA have 8 evenly spaced screw holes. Do the newer and older 11" OTA's have the same diameter, or did that change in 2006?
Has anyone tried to fit one of the new dew rings to a Celestron SCT pre-dating 2006? Thanks for any information anyone has on this.