Topband: Hairpin Matching Coil Questions

[Jim GM]

I have an inverted L and using a hairpin coil to match in on 160M.

One coil is 6 inches OD the other is 2 inches OD.  I have been thinking
about making another hairpin with wire wrapped around a toroid donut,

I have noticed with the 6 inch coil I have a higher noise level on 160M and
hear BCI pretty strong on certain frequencies on other bands.

The 2 inch coil has lower noise level on 160M and BCI is reduced on other
bands.

If I use a toroid hairpin What would happen to the noise level and BCI?  My
guess is both will be reduced a bit more.

Also what hairpin matching coil should I use and why?

-- 
Jim K9TF