Compare the RT Systems USB-29A and USB-RTS05 cables
USB-29A and USB-RTS05 comparison

On some Icom radios the USB-29A and the USB-RTS05 cables are offered for programming. This comparison is presented to help you decide between the two cables.
USB-29A The USB-29A programs the radio with which is it shown. It addresses the radio through the 3.5mm speaker jack.

The USB-29A can be used to program many of the Icom handhelds and mobiles as well as radios from other manufacturers. It is one of the more "universal" programming cables in the RT Systems line.

Programming through this cable with most radios is easier than when using the USB-RTS05 cable. The data port into which the USB-RTS05 is often busy with other data from the radio. This data can interfere with the stream of data that programs the radio. This interference can cause failed starts in the Get and Send data process, bad programming data reception (think of two things talking to you at one time... you could mix up the conversations... just think what you poor little radio is being asked to do!!) and often, erratic movement of the mouse on the screen (those signals have to go somewhere!!)

If you are planning only to program the radio with this cable, get the USB-29A.

USB-RTS05 The USB-RTS05 programs the radio, sometimes can be used for data with other programs such as D-Rats, and sometimes can be used for firmware upgrade to the radio. It connects to the radio through the data jack.

This cable is not as universal as the USB-29A in its use with other radios for programming; however, it can be used for data and programming on many Icom D-Star radio models.

Note: Be aware that you must turn off GPS from the controls on the front of the radio when using this cable for programming. Erratic movement of the mouse, failed starts for programming, or failed programming attempts will occur if GPS is on. If you are only going to be programming the radio with the cable and software, use the USB-29A.