HFSAT Duplexer design welcome,

If anyone wants to take a shot at designing an HF Duplexer so that the single 29 MHz dipole can also be shared with the 21 MHz uplink, here is the schematic (maybe): http://aprs.org/hfsat/HF-duplexer-a.png

It is my guess at how to build a trap and pass band on each side of the duplexer. But then I am not an RF designer at that level.

The overall web page for HFSAT is: http://aprs.org/hfsat.html

Bob, WB4APR