tk545 - Computer Control Software for
the Japan Radio NRD-545 Receiver

Copyright 2003, Bob Parnass

NRD-545 photo


tk545 is open source software designed to control and program the Japan Radio Co. NRD-545 receiver. An introductory article about this software appeared in June 2002 Monitoring Times magazine.

I implemented tk545 in the Tcl/Tk scripting language which enables it to run on a variety of operating systems, including Linux, MacOS X, Microsoft Windows 98, and Windows XP. The free Tcl/Tk interpreter software must be installed on your computer prior to using tk545. Ben Mesander tested tk545 on a MacOS X laptop provided these instructions. A newer version of MacOS X installation instructions appear here. Steve Walker tested tk545 on Windows XP. I have not tested it on other platforms, but it will probably work on them after little or no modification.

tk545 is distributed free of charge, but it is neither shareware nor in the public domain. tk545 is a copyrighted work released under the terms of the GNU General Public License as published by the Free Software Foundation. tk545 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

Most NRD-545 controls are available on tk545's Main Controls window (fig. 1) and Secondary Controls window (fig. 2), including important adjustments which are normally buried within the NRD-545's menuing system. For example, you can adjust the DSP noise reduction level and Line Enhance settings while listening to a signal. The Beat Canceler level is another example. These controls are difficult to adjust using the NRD-545's front panel but easy to access using tk545 .

tk545 software provides 1 Hz frequency resolution. The radio's vacuum fluorescent display is limited to 10 Hz resolution.

Less frequently used parameters may be accessed using the Options pulldown menu, which may be "torn off" and used as a separate window (fig. 3).

tk545 can be used to load the NRD-545 memories or read memory data from the radio and store it in a file.

Data files are in csv (comma-separated values) format, so users can create or edit them using spreadsheet or text editor programs.

tk545 software provides a facility to log and timestamp frequencies and relative signal strengths to a log file in csv format. For example:

2002/02/04,20:13:32,1.340000,am,6.45,"WJOL Savage Nation"
2002/02/04,20:15:47,10.000000,am,5.43,"WWV steady signal"
2002/02/04,20:16:46,7.335000,am,2.77,"CHU time signals"

Memory Channel Files

tk545 can read files containing memory channel data. Using the mouse, you can click on a particular entry and tk545 will tune the radio and set the mode and AGC decay times accordingly (fig. 4).

You can also download the memory data from a file to the NRD-545, thus programming its memories.

A memory channel data file must be formated in csv (comma-separated values) format. The first line of the file should be this heading:


All the other lines should contain these fields:

Channel number (0 - 999)
Frequency in MHz
Mode (am, ams, eccs/l, eccs/u, usb, lsb, cw, fm, wfm)
Selectivity (narr, inter, wide)
AGC time in seconds (.04 - 5.1)
Comment (an optional comment which should not
	contain a comma or quotation marks.)

This is a sample memory data file:

0,0.58,"am","wide",0.2,"WILL Univ of IL Urbana"
3,0.72,"am","wide",0.2,"WGN Chicago"
5,0.78,"am","wide",0.2,"WBBM Chicago"
6,0.85,"am","wide",0.2,"KOA Denver"
105,5.55,"usb","wide",2,"ICAO overseas flights"
106,5.565,"usb","wide",2,"ICAO overseas flights"
107,5.598,"usb","wide",2,"ICAO overseas flights"

You can use a separate text editor or spreadsheet program to create, edit, and print memory channel files. You cannot create or edit memory channel data files within tk545.

Downloading and Installation

tk545 is undergoing development. To download a beta test version, including source code, click on the appropriate link to the left.

Revised October 26, 2002