It had been enough years since I’d used my Kenwood TH-D7 that I couldn’t remember how to get it to connect to my MacBookPro.  Mostly for my own reference, and possibly to assist others, I’ll post my quick notes here.

• I used my Keyspan USA-19HS USB to Serial Adapter along with a Kenwood PG-4W programming cable.
• Of course I needed to install some drivers to get the PL2303 Serial Driver to work in Mac OS X Yosemite, and the original project I used to use is still there and had the source for free, but you had to pay for the download. I did eventually find a download link to the Keyspan USA-19HS driver (here is the direct file link)
  2023 Note: For newer M1 MacBook Pros running Sonoma and needing a Prolific PL2303 Serial Driver, it looks like this works: Prolific V.2.2.2 
• Next I just plugged in the Keyspan device, plug the radio in to it, and turn the radio on.
• Launch MacMemoriesManager and selected the Radio Kenwood TH-D7 and for Port selected USA19H143P1.1. It immediately connected and I could download all of the frequencies from the radio.

Awesome :-)