I have had my Sharp's Carousel microwave for a good number of years and it still works very efficiently. However, I was wondering if there is any way of checking whether it is still safe. Thanks for any advice.
My late mother-in-law had a little gadget that you held up and around the door while it was working to check it for leaks but I can't remember what it was called. They are out there though.
However, as Heathfield states, as long as the door still seals properly there should be no problem. (My microwave oven is 21 years old but I've got no concerns with regard to its safety).
I have to assume that Canary42 has never built a radio transmitter!
One of the great advantages of using microwaves for radio communication is their relatively low level of atmospheric attenuation. (i.e. rather than 'not travelling very far' they're particularly good at travelling quite long distances!).