If I were going to do what you're asking, I'd buy a cheep SDR dongle and tap into one of the I.F. trains inside the receiver BEFORE the I.F. filters. Then, you could use virtually any of the SDR freeware out there, like SDR# (SDT Sharp) set it for 'DIRECT SAMPLING' , tune it to the I.F. frequency and watch your spectrum on the large computer monitor. That way you have the excellent Kenwood transceiver AND a "Fish Finder" thingie in the shack.
(https://consumerexpert.org/wp-content/uploads/2017/05/best-fish-finder.jpg)
- Sir John Honeybucket