Jim Siemons wrote in :

Hi, Mike:
The most important factor is that you choose the correct cable to
connect your FT450 to you computer. I have spoken to a number of hams
and have witnessed on other sites comments that they have difficulty in
connecting the radio to their computer. If you get the right DB9 to USB
cable or DB9 to whatever your computer is looking for serial cable you
should be in good shape. Just looking around, I see that most folks
are using a DB9 to USB cable. I chose one that came with a small CD
disk to drive the cable. In my mind, normally I would not need a disk
to drive a cable - but what the little app did was match up the data
from the correct pins. I saw some cables in the store that did not
have all the pins in their DB9 connector. That might be OK in some
applications, but I didn't know what the FT450 or HRD was exactly
looking for - so I wanted all pins to be able to be activated.

Bottom line, my cable worked. I purchased my cable from a Fry's
Electronics store in Concord, CA. There were 6-7 or more DB9 to USB
cables that I could choose from (that was kind of amazing in and of
itself). I fritz around for awhile, looking at the specifications on
the packaging and chose one. The one I picked was not, incidentally,
the most expensive one.

Inspect your cable and make sure that you are getting voltage out of
the radio.

The USB-to-Serial adapter is known good: it works with the FT-897D. But
with the FT-450, I have to use a longer serial cable, which I suspect. So,
oddly enough, that was going to be tonight's project: ohm the cable out,
then put the cable on the computer's serial port, put the scope probe in
the other end, and look for state changes as I change things in HRD and
MixW, and finally put the cable on the radio and look for state changes on
the computer's end of the cable as I tune.

--
The correct policy approach to a non-problem is to have the courage to do
nothing.
--Christopher Monckton