Rotor Controller Software Downloads
RT-21 Setup Utility 4.10
The RT-21 Setup Utility allows you to manage configuration options and optimize other controller settings from your PC.
New 4.10 version Feb 2022
Supports all the RT-21 4.13 Features including LAN and TCP.
Adds the latest features in the current RT-21 and RT-21Az/El v2
RT-21 USB Driver (Silicon Labs)
Due to Chip Shortages, RT-21 and RT-21 Az/El beginning in November 2022, began shipping units containg a Silicon Labs CP210x USB chip. These units are easily recognized in Windows Device Manager as a Silicon Labs USB Serial Bridge and may require installation of this USB Driver.
Additional information and drivers for other platforms (Mac) are available at
RT-21 USB Driver s/n <2000
USB Driver for RT-21 S/N < 2000. This INF file enables standard Windows driver to be used with these RT-21 units.
RT-21 USB Driver s/n 2000+
USB Driver for RT-21 S/N 2000 and higher. This is the standard driver set for the FTDI chip and is part of newer Windows releases and Windows update too.
RT-21 Firmware 4.13
The current RT-21 version 4 firmware. (and two revs back)
V4.13 adds LAN and direct TCP modes for Ethernet OR WiFi
NOTE: Version 4 FW is only for controllers above s/n 4000 (v4 controller CPU)
.zip includes latest firmware for K7NV (Prop Pitch) and K0XG units as well.
RT-21 Firmware 3.08.9
RT-21 Firmware latest v3 Release along with complete RT-21 revision history and load instructions.
3.08.9 for s/n 2000 to 3999 units (v3 ONLY)
.zip includes firmware for K7NV (Prop Pitch) and K0XG units as well.
RT-21 Firmware 1.07.n
Old version for RT-21 below s/n 2000. must be 1.nn firmware unit.
Downloads for K0XG, K7NV and RT-21
RT-21 Az El Firmware 1.04
RT-21 Az El Firmware Current Release 1.04 Nov 11, 2015
Adds Brightness Control for OLEDS v2.0
RT-21 Az El Firmware Version 2
RT-21 Az El Firmware Latest Release 2.013
DO NOT INSTALL IN V1 Controllers!
See the text document and the Az/El V2 manual for more information and revision history.
RT-21 GH Map Version 2.0.2 adds embedded Java (see Release Notes)
A simple and basic graphical RT-21 control program intended for mouse or touchscreen operation by dragging the desired beam pattern to a desired heading. This program supports up to three rotators on one graphical display. We provide a default compass rose background but you can utilize any graphical background you wish. Background Azimuth projection maps centered on your QTH are readily available on the web and can be simply selected for use as your background image.
RT-21 Console Firmware
RT-21 Console is a download firmware load for any RT-21 that converts that unit into a control console for another RT-21 controller. Essentially, the RT-21 Console implements a “computer terminal” in an RT-21 unit that sends and receives RT-21 commands over an RS-232 link. Both the rotor connected RT-21, and the RT-21 Console can control the attached rotator, and view headings.
RT-20 Last Production Versions (OLD)
Old RT-20 firmware….in RT-20, there are different loads for AC motors than for DC motors.
The 2.02 is the AC motor version (Hy-Gain, create etc.)
The 1.05 is the DC motor version (Orion, SPID etc)
TIC Rings, K0XG, and Prop Pitch versions are all separate and the files are included.
The ending ‘a’ denotes a PCB version of 1.8 or later. Earlier boards used the firmware NOT ending in ‘a’
The included loader must be used….after starting the load, you must cycle power quite quickly….< 1/4 second off time.
Call us if you need help…but we would recommend that it’s better to spend the $25 for an RT-21 CPU upgrade instead.
Jeff – W2FU
GH Tracker 1.24
Newest Version includes MacDoppler UDP interface 1.24 includes imbedded Java Runtime, no need to download or maintain Java on your computer.