KPG-74D COM port in Windows 11

[Agent713]

Hey everyone. I have an old Kenwood TK-3140-1 that I'm trying to program with the KPG-74D software and the KPG-36 cable and a valid serial with Windows 11 x86. I successfully programmed this radio several years ago with an earlier version of Windows.

The issue is the COM port. As soon as I plug the usb into the computer Device Manager shows "This is not Prolific PL2303. Pleas contact your supplier." I have tried to change the COM port settings in Device Manager but still can't get the programming software to see the COM port. (The COM port selections are all greyed out.)

Any help would be appreciated!

 

[Vern]

A lot of folks having trouble getting USB programming cables to work under Win-11.
Same thing happened w/Prolific cables some years ago, under Win-8, I think.
You might try rolling back the Prolific driver in Win-11 to an earlier version, but that's only a temporary fix. When Windows does an update it'll update that older driver with their newer (not working) version. You'd have to do the rollback every time you want to use cable.
An option is go to BlueMax49ers.com and get his FTDI-chip cable for your radio. Select Win-11 as your OS when you order.

 

[Agent713]

Fixed. I guess the latest Prolific driver doesn't like my cable. Found an old driver installer, uninstalled the current driver and deleted it, ran the old installer, rebooted computer, and voila.

Thanks Vern, was about to pull the trigger on a BlueMax49ers FTDI cable then tried one last time with a driver I found.

 

[a417]

Fixed. I guess the latest Prolific driver doesn't like my cable. Found an old driver installer, uninstalled the current driver and deleted it, ran the old installer, rebooted computer, and voila.

Yes, this is a known issue. Save that driver somewhere special.

 

[ramal121]

Now that is odd because a true KPG-36 uses a chip from Silicon Labs. Their latest driver is 11.3.0 and it came out in May. Kenwood posted it in October. Works with Win 10 & 11, but nothing older.

 

[Agent713]

Now that is odd because a true KPG-36 uses a chip from Silicon Labs. Their latest driver is 11.3.0 and it came out in May. Kenwood posted it in October. Works with Win 10 & 11, but nothing older.

I'm assuming my KPG-36 is not a "true" cable with a Silicon Labs chip and the latest Prolific driver checks the chip. I guess the older drivers don't check the chip and just work. I bought this radio 2nd-hand about 13 years ago with the software and cable together so I don't know the original source of the cable.

 

[ramal121]

Makes sense. If it works now and the device manager reports a Prolific chip well there ya go.

 

[AM909]

I'm assuming my KPG-36 is not a "true" cable with a Silicon Labs chip and the latest Prolific driver checks the chip. I guess the older drivers don't check the chip and just work.

Right. Someone started copying the Prolific chip, and someone started buy the illegit chips and using them in cables and devices, so Prolific retaliated by making new drivers that don't work with the fake chips. This page was good.