[wireful3]

Darren has made a very interesting point and I agree that grid coupling capacitor is probably more helpful to a newbie for understanding what is happening.

The output valve coupling capacitor is so notorious that when it is used in describing a restoration, in "success stories" I have had no problem in understanding what is meant. The first time I came across it in that context I felt it lightened the tone a bit and made it more like a story than an engineering report.

Where that gets me I don't know! Perhaps I have just confused myself. I must admit that it had never realised that it might be used to mean any other.

Not being a Prime Member (I prefer dogs to cats) It never occurred to me that it was a mis-spelling or typo. Perhaps it explains the occasional finds of dead flies or spiders when people have needed to feed the cat.