Hi, after many years of not using it, I have found some space on my desk to fit my TS-680S and need to think about an antenna.

I'm curious enough at the moment to put up a silver rod type antenna I have, the original SRC X80 in a vgc state.
(A 21 foot silver rod with an unun in the base).

This was originally sold as not needing radials, however a little online browsing shows that it is far better and has a lower noise floor if you add radials.
I have a scaffolding pole on T/K brackets at the rear of the house and it can fit on that.
However, does anyone know at what length I could make radials for it?

I have seen a picture of the radial kit for the version that replaces the original?
I'm thinking of adding some shorter wound radials, any suggestions please?