These are my favourites

It's noisy though. It makes a high frequency squeeky buzz like no other tube has done. It's my only example. Is it worth saving, not using? Anyone know its age? My guess would be 1970s - 1980s at the latest.

May 1981 I think. If you've got a decent amount of others use it if not don't. Does this have that faint ringing sound when in use?

I had a 20w Osram liteguard tube in my plugin light ideas fitting with diffuser, and that made the noise you describe. I always thought it to be the resisitive ballast but it was indeed the tube. That tube was bought in 1983 and failed in 1987 but Kev let me have one of his 20w liteguard tubes! Had been after one for years!

Danny that's the noise I describe. High frequency ringing, and it's not so faint. I can hear it downstairs from upstairs. If I were blind I'd know when the landing light's on. Since it's my only one I'd better take it out of use and replace it with something else, perhaps a Kolorite. Push the boat out, aye?