[R-390] A 6kc. mechanical filter for a R-390a?

[Al S.]

I have one of the more modern blue cased Collins mechanical filters here.
It was apparently used in the Racal 6790 receiver BW is 6.0 kc. 526 9957
040.

This filter is designed to be used in that SS receiver and for lower
impedance, than the higher impedance the stock 390a filters see.

I would like to experiment with this filter in a 390a. Any ideas on
toroidal matching to the IF deck in the 390a.

Thanks

Al VE3AJM