Certainly you can use the antenna if the tuner tunes it.  In the old days, 
rigs would match a coat hanger.  Of course because it will match doesn't 
mean it will radiate, example would be the dummy load.  It might work fine 
though.  I've found the same thing sort of, with my windom.  It was 
resonant way below 1.8, good on 80 and matched way above 7.3.  i don't 
know why, but it tunes so I use it and it does seem to work fine.

Remember swr is simply an impedence ratio, but really doesn't count in 
reactance.  If you have an impedence of 100 or one of 25, the swr is the 
same two to one.  As I recall, six percent reflected is around 1.5 and 11 
percent is around two to one.  If I recall the formula, it is
the square root of the quantity left paren forward plus reflected right 
paren squared divided by left paren forward minus reflected right paren 
squared.  So if we put in some easy numbers, say you have a forward of ten 
watts and a reflected of one watt.

The numbers would look like square root of
ten plus one which is eleven squared which is 121  bottom quantity is 10 
minus 1 which is 9 squared which is 81.  So the swr is 121 over 81 which 
is 1.493

Probably more than you really wanted to know.
73
Butch
WA0VJR
Node 3148
Wallace, ks.