List, The discussion about building a H Maser has been fascinating however it appears that there will be a long time period before the project reaches fruition. My questions for those that have a H Maser are: Where and when did you get it and what was the cost? Exactly what do you have to do to keep it operating? Lastly where would one look to get a GOOD used H Maser and what would it cost (rough guess is fine)? Regards, Perrier