IIRC tjhat switchbox contains what we (in the UK) call a 'Balun'. I am
not sure if that term has crossed the Pond, it's an abreviation of
'Balanced <-> Unbalanced'.
In the US, the term "balun" is not used by the general public. It's used
Ove here, the 'genral public' wouldnt' know what a matching transformer
was used for :-)
mostly by people into radio professionals or hams.
In othe words people who need to talk about such thigs.
The term 'Balun' is commonly used by RF engineers, radio amateurs, etc
over here. It sounds like it's used in the same way in the States too. I
wans't sure, it might haver been one of those terms like 'Valve' which is
different ion the States.
-tony