I recently came into a couple of E-Tech IM400 UHF Radios, but could find no information online on how to actually program them. This page summarises what I found and I hope may be of some use if you come across these radios.

A black mobile radio sits on a desk with text "thegame" on the screen
IM400 Radio on the bench. More descriptive channel names are recommended.

First, we had the task of finding out where programming data actually goes into the unit. After some googling, I found the following pages about these devices. Programming is performed over the front RJ45 connector, with a pinout that isn't in the manual.

This page contains a variety of information about the device including the pinout of the rear connector, frequency ranges, installation and other details.

After (a lot of) googling, I also found the programming software on the original manufacturer's website. The software can only be found when the website is used in Korean, with a much smaller set of downloads shown when using it in English.

The manual for the E-Tech IM400 can be found easily amongst regulatory data, but contains limited information about the electrical characteristics of the device.

Tracing a few pins with the radio taken apart, it was found to accept UART directly into the processor from the RJ45 front panel connector. This seemed weird as the one or two programming cables I could find online were adapted from RS232, which (when used in-spec) often uses a much higher voltage than the 5V MCU should be able to handle without a transceiver IC. Possibly the manufacturer was betting on most USB-RS232 adapters not going much above 5V, or there was some kind of level shifting included within their manufactured cables.

If you cut in half a standard ethernet cable terminated with T568B, the following pins allow you to program the device. I used a C232-HM 3.3V UART cable.

ethernet pinradio functionconnect to
stripy orangeRadio RXDUART adapter TX
stripy blueRadio TXDUART adapter RX
greenRadio GNDUART adapter GND

The software menus are by default in Korean but the most crucial settings are in English or easily interpretable. Be sure to select your radio model from the relevant menu before attempting to program.

If you're going to use this cable, do so at your own risk as I don't know if it changed between revisions, manufacturers or models. These radios were also sold under the brand names Tekk and Iris, and there is also a VHF variant of this radio, the E-Tech IM100.