I have a post here from years ago building off this idea, the guy used a home brew heater that was soldered to a strip of metal, and formed to fit over the crystal much similar to thisI am intrigued, and I have an old camcorder somewhere. Once upon a time, if I found an old camcorder for nothing, I would rob it of the the mini crt eyepiece. If I remember correctly, they mostly took a composite video input and 5 volts DC to operate. I used those for many projects, including a portable, battery powered spot monitor for CCTV cameras and for configuring head-less devices.
HEATER-HC49-60C
Mini-Kits manufacture 60 degree C clip on crystal heaters that are ideal for stabilizing frequency stability with temperature changes.
Here is the more modern version
EME177-R2 Crystal Heater
The EME177-R2 Crystal Heater has been specifically designed to help stabilize crystal frequency drift due to temperature changes.
73
Jeff
