Thanks very much, Alice and Margarita for the comments and the references - very encouraging - when I've got rid of my current catarrh I'll go and find a bin - we have plastic wheelie-bins which I think will be acoustically dead, so I'll have to look around a bit.

A bit of synchronicity struck today, a colleague, much younger than myself was saying how she had lost the voice she had when young, with a nice trill, which led to another colleague, ex-chorister telling how he had been told never to use vibrato - women's voices wobble! I'm glad to hear his choirmaster was leading him astray(?)

I think, though, from what you say, that I may be doing things generally right, with a need to work on the breath support - practice required.

Thanks again, Penny