The Kenwood programming software is a free download. Just go to Kenwood's site and get the "MCP-2A" program.
The 'Data' jack is the one you want to use. It's a 6 pin round jack on the '71A. Kenwood's cable has a 9 pin DIN connector on the other end (not worth the price) which connects to the computer. My computer doesn't have a 9 pin serial port so I use a serial to USB converter to connect that data cable to my computer. I already had a data cable and USB converter so can't tell you where to find the pin-outs for them, but, Kenwood manuals should have it in it somewhere. Making one is one option, or buying one is another. That 'Data' jack is a standard one, I think all brands of radios use the same pin-outs. The required cable ought to be fairly common, I'd think.
The serial to USB converters are a different story, there are a number of them, all of them don't work with all computer's operating systems. No idea what you have so can't make any recommendations with that. (Not real sure which one I have either, so I'm no help with that at all.)
Best advice is to read that manual! It'll tell you what you need, and need to know. When you get totally confused, ask more questions (I had to also).
The "DATA" jack passes audio to and from the radio and is used to connect the radio to a computer sound card for modes such as Echolink. The DATA jack is a 6-pin mini-DIN.The 'Data' jack is the one you want to use. It's a 6 pin round jack on the '71A. Kenwood's cable has a 9 pin DIN connector on the other end (not worth the price) which connects to the computer.
The "DATA" jack passes audio to and from the radio and is used to connect the radio to a computer sound card for modes such as Echolink. The DATA jack is a 6-pin mini-DIN.
The "PC" jack passes binary data to and from the radio and is used for programming the radio. The PC jack is an 8-pin mini-DIN.
In order to program the radio, you need a cable which will connect to your computer at one end and the PC jack at the other end. Your options for this cable are:
Note that if your computer does not have an RS-232 port with a DB-9 male connector, you may need to purchase an RS-232 to USB converter. For computer programming of radios, some work, some don't. If you can find a cable with the FTDI chip and if you load the proper drivers, it very likely will work.
- Buy Kenwood PG-5H kit which includes both Data and PC cables.
- Buy an 8-pin mini-DIN serial cable. This type of cable was used, I believe, to connect printers to early Macintosh computers. You can find cables on-line with a male 8-pin mini-DIN plug on at least one end. You then cut off the other end and connect a 9-pin DB-9 female connector using the pin-outs shown on page 90 of the TM-V71A manual. I have done this a couple times in the past and it works.
- Buy a pre-made 8-pin mini-DIN male to 9-pin DB-9 female cable. One source is PCCABLES.COM - Computer Cables, Camera Cables, HDMI Cables, VGA Cable, DVI Cables, USB Cables, Network Cables, Firewire, Power Cord -- search for part number 70810. At $7, it's much cheaper than buying the cable from Kenwood and doesn't require cable assembly skills.
- Buy a pre-made 8-pin mini-DIN male to USB cable from RT Systems -- part number USB-K5G. It's been reported that this cable works fine with Kenwood's software. Price $30.
One note about programming this radio with the newly-licensed "narrow band" frequencies: The narrow band licenses in the VHF public safety and business band are assigned on a 7.5 kHz channel spacing. The TM-V71 does not have a 7.5 kHz channel step size (nor does it have 2.5 kHz steps). As a result, you may not be able to program some narrow band frequencies. The Kenwood programming software and the radio will round to the nearest 5kHz which means you'll be at least 2.5 kHz off frequency.
I do not have direct experience with this cable. However, here is the response from Bill AC8IH in the TM-D710/TM-V71 Yahoo Group when I asked if the RT Systems USB cable would work with Kenwood's software:Are you pretty sure the 30 dollar cable USB-K5G you list will do the job?
ABSOLUTELY - that is how I have my TM-D710A hooked up here and the RTSystems cable works with their software, with the Kenwood MCP-2A program and with UI-View. I've even used it with a terminal program (HyperTerminal) to send direct commands to the TM-D710.
Maybe the only 'different' thing I do with the programming software is to turn the "Tree" view on. That just makes it more convenient for me to get to several of the setup features than using the 'buttons' at the top of the program screen.
Most of the things in the program are explained pretty well under the "Help" button. Go through that list and see if there's anything that you may want to do or change. Go through all of it! Lots of things that probably won't be understandable immediately, but they will after you 'play' with things for a while. The 'default' settings will usually tide you over until you find something that you want to do differently. (I don't use the 'Voice' announcement thingy so have turned it off. I also like the 'green' screen better than the amber, so changed that too.)
My 'way' of doing things may not suit you at all, so finding out what's available/desirable for you is the thing to do. It takes time so don't try to do everything to start with. At least get a fair understanding before changing things randomly. It's also a very good idea to 'save' the original default setting under a unique name before making changes, so you can put everything back if you make a mistake or change your mind later.
I'm not sure what else may be worth telling you, so you 'noodle' around in there and see what you think. Have fun.