[Elecraft] Question about antenna matching

[Al Lorona]

This question is about how manufacturers spec the matching range of their antenna tuners.

If an antenna system presents an impedance of 5 + j0 ohms to the antenna tuner, that's an SWR = 10 to 1.

But, an antenna impedance of 50 - j143 ohms is also SWR = 10. So is 110 - j200 ohms.

When a manufacturer like Elecraft says, "Our antenna tuner can match a 10:1 mismatch," does that mean the tuner can match the first case above, the second case, the third case, or all three?

I guess what I'm asking is, are all of the impedances above equally difficult for the same tuner to match? Or is one 'harder' than the others? It would depend on the values of the L and C in the tuner, wouldn't it? Which implies that certain 10:1 mismatches are not tunable?

Thanks,

Al  W6LX/4