In an HF tuner, how much of a disadvantage would a toroidal inductor be compared with an air cored inductor?

The difference is probably not noticeable - you can achieve very similar values of Q if you use the correct core and wire.

For example, according to W8JI, an air-cored coil wound with #12 wire has a Q in the range 300-500; a large #2 iron powder core has a Q in the range 500-600 at 1.8MHz.

Steve G3TXQ

Thanks, as long as it wasn't a major difference, I would have been happy.