You are 100 % correct. I have went to the site today before I seen you post and put a dummy load on the TX side of the Telewave and plugged the TX antenna into the PA of the repeater. It was unable to receive and just kept dropping out when someone would key up with no audio. Obvious desense. Oh well, it probably not worth the trouble to get it retuned on site to adapt as my access to the DB420 could go away at any time.
Thanks you all for your help with this. What a learning experience!