If the cable works to Get Data from and Send Data to the radio with the RT Systems software - but can't get it to work with HRD:
  1. Make sure connection for the CAT/Linear jjack on the rear of the radio radio is set to CAT(menu item #20)
  2. May need to adjust the Cate Rate (menu item #19) Generally, the faster the better so start at the highest setting and adjust down as needed. Most computers today (2020) will time out if you are trying to use 4800 for the CAT Rate.
  3. Radio needs to be in VFO mode.
Instructions to get to menu item 20:
  1. To get to menu-push and hold the function key
  2. Extended menu-must be on (turn right knob to change)
  3. Turn up to menu item #20 - to CAT/Lin/Tun
  4. Be sure it is set to CAT. If not change to CAT.
  5. Turn to Menu item 19. Check that it is on a value other than 4800.
  6. Press and Hold the function key until you return to the frequency
Need to be in VFO mode (displayed in upper left corner) press VM key on side of radio if needed.