I have successfully got FT891 running under TRX-manager: http://www.trx-manager.com/index.html
1) Install the dual serial port driver from Yaesu website.
See manual here: http://www.yaesu.com/airband/downloadFile.cfm?FileID=9515&FileCatID=42&FileName=USB%5FDriver%5FInstallation%5FManual%5FENG%5F1610%2DB0.pdf&FileContentType=application%2Fpdf
(Note: the 891 has dual serial ports, it does not have an USB soundcard).
2) Reboot the PC and check that you see two serial devices in your Device manager (type device manager when clicking the start button)
3) Hold F on the FT-891 in a couple of seconds (long click)
4) Goto menu 05-06
Set CAT RATE to 38400
6) Goto menu 05-08.
Set CAT RTS to DISABLE (unless you do that you may have a problem getting data thru)
7) Set the rate to 38400 in TRX-manager (setup menu) and select FT-891. Also select correct COM port (on my PC it was COM5. It may be different on yours).
Remember: unless you set CAT RTS to DISABLE (see above) you will not get data thru and you will mess around in the TRX-manager menus while the problem was a setting in the FT-891 menu.
8) Stop and restart TRX-manager
9) You may hear a clicking sound for every CAT transmission in your FT-891 loudspeaker (A bit annoying… I have to admit that even if I like Yaesu radios)
10) Click F on the FT-891 (short click)
11) Goto MON on the FT-891 menu
12) Click on MON
13) Turn down the MON level to 0
Note: This applies regardless if you have MON ON or MON OFF (this is a bug in Yaesu’s firmware. Rare. LOL)
14) Now you have CAT control without any clicking sounds on your FT-891
15) Enjoy your Yaesu FT-891
Comments about the FT-891:
Plusses: the FT-891 has in my view a better and more modern RX than the ageing FT-857, even better than IC7300 (some ppl. claim) http://www.eham.net/reviews/detail/13042?page=2 , it is a low cost modern mobile 100W HF rig with a small detachable front, it has DSP RX, a nice variable RX filter, works well down to low voltages even if someone claims it doesn’t, has a much better menu system and a better VFO, it has a reasonable current draw on RX (even if the datasheet overstates this a bit it is below 1A on my rig).
Minuses: No VHF or UHF ( however that may be a benefit. Not the compromises that probably are in the 857 rf chain). No USB soundcard (do you really need that in a mobile station?), 60M USB has to be programmed in a memory and you go memory tune from there and it will keep USB even if you are below 10 MHZ.