1.2 The original HX300 programming interface
The programming interface of the Standard Horizon HX300 utilizes a mini-USB connec-
tor which is also used for charging the radio. It should be noted that the communica-
tion between the PC and the HX300 does not actually take place using standard USB
communication. A direct connection between the PC and the radio, using an ordinary
USB/mini-USB cable will only provide charging of the HX300. Programming the radio
will not be possible using an ordinary USB/mini-USB cable.
The original programming software for the HX300, named CE134, includes schematic
which details the required parts, as prescribed by Standard Horizon:
CT-172 cloning cable, which hooks up to the mini-USB-like interface of the HX300.
USB-62B cable, which (1) adds a serial port via USB to the computer and (2) provides
voltage level conversion to TTL levels (5V).
The USB-62B cable is easily available as it is commonly used also with Yaesu ama-
teur radio transceivers [5] — hardly surprising, as the Standard Horizon brand is con-
trolled by Yaesu Musen Co., Ltd., well-known manufacturer of amateur, marine and air-
band transceivers.
It should be noted that other interfacing options also exist, as detailed in section 2
of this document.
Figure 1: Original programming setup for the HX300 as described in the CE134 documentation. For
reasons unknown, the CT-172 cable assembly seems somewhat hard to get hold of. No worries, there are
several other options available.
http://www.annoyingdesigns.com/HX300 3
