Currently I have no other SWR measurement equipment, except SWR meter built in FT450AT. It shows perfect flat SWR up to 50mhz, as it will do when directly hooked to dummy load. Regarding the insertion loss, it was not in measurable range from 1 to 30 mhz, it showed up itself only below 200khz. Below is attached schematics of my bias-t.
Did you try it with just the single .68uF cap and a single coil? Isolation to the DC port may be a little less, but that is really not that critical. I have never seen these things that had to use two coils.
Usually, there is one cap in series, or maybe multiple parallel caps working as a single high current series capacitor, then a single non toroidial inductor of about 150uF or so. Then a couple of caps at the DC side of the inductor.
Ahhh....you used two inductors. With the circuit you have it is possible to control two devices just by using reverse polarity. If you're looking to have voltage applied to a pre-amp mounted on the tower then you would use a bridge rectifier and it will always have the proper voltage regardless of polarity.
It would be better to parallel C1 and C2, but if it works for you then don't mess with it.
Just a thought.