I'm not a ham operator! But I figure you guys can explain what an
Isolation Transformer does.

I came up with one at an estate sale this weekend of a former TV
repairman. Among the 1970s vintage test equipment and color bar
generators was this xfmr. This unit says "Isolation Transformer 5
Amps, 600 Watts" on one side and "Isolation: Primary 120 VAC,
Secondary 120 VAC" on the other. It's about 8" square and as you can
imagine, quite heavy.

I was guessing it keeps voltage spikes out of the equipment that's
plugged into it, but then I saw some old posts in this group which
mentions grounded chassis.

Do people who have fairly modern ham equipment still use these things?