There is coverage in various places of the US export totals for 2011,
heavy on the fact that our #1 export is fuel. But not far down the list
is . . . vacuum tubes. I had no idea that the US manufactured so many
vacuum tubes or that the market was still so big.

http://tinyurl.com/7ebyodz for the article at the Washington Post

The top exports in 2011 (thru October) were

1 — Fuel: $73.4 billion;
2 — Aircraft: $70.8 billion;
3 — Motor Vehicles: $39.6 billion;
4 — Vacuum Tubes: $37.1 billion;
5 — Telecommunications Equipment: $33.2 billion.

Following the history of vacuum tubes,

2010, #3, $47.3 billion
2009, #2, $37.7 billion
2008, #4, $50.6 billion
2007, #2, $50.2 billion
2006, #2, $53 billion

Looks like the health of the economy really affects consumption.

So where in the US are these manufactured?

73, Steve KB9X