tk500 - Experimental Software for
the Yaesu VR-500 Receiver

Copyright 2004, Bob Parnass
VR-500 photo


tk500 is open source software designed for the Yaesu VR-500 receiver. Though it is chiefly intended for Linux, MacOS X, and BSD users, tk500 will work on Microsoft Windows, too. An introductory article about this software appeared in July 2002 Monitoring Times magazine.

The current, experimental version of tk500 can program three versions of VR-500: USA, Japanese, and Export. It can:

I implemented tk500 in the Tcl/Tk scripting language which enables it to run on a variety of operating systems. The free Tcl/Tk interpreter software must be installed on your computer prior to using tk500. I am looking for beta testers to try tk500 in the MacOS X environment.

tk500 is distributed free of charge, but it is neither shareware nor in the public domain. tk500 is a copyrighted work released under the terms of the GNU General Public License as published by the Free Software Foundation. tk500 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.

Memory Channel Files

tk500 can export memory channel data to a file. The memory channel data file is formated in csv (comma-separated values) format. The first line of the file is this heading:

All the other lines will contain these fields:

	Channel number (0 - 999)
	Frequency in MHz
	Mode, case insensitive (optional: am, usb,
		lsb, cw, nfm, wfm)
	Preferential flag p (optional)
	Label (an optional 8-char name)

This is a sample memory data .csv file:

	1,460.5250,nfm,p,"Kendl P1"
	2,460.5750,nfm,p,"KC Fire1"
	3,460.3750,nfm,p,"Kendl P2"
	4,462.9750,nfm,p,"KC Fire2"
	6,155.5800,nfm,p,"Oswego P"
	7,145.1700,nfm,,"IH rptr"

When the mode for a memory channel imported from a CSV file is not specified, the mode will set according to the Auto Band plan.

You can use a separate text editor or spreadsheet program to create, edit, and print memory channel files.

Computer Interface Adaptor

You will need a suitable TTL-to-RS232 level adaptor to connect the radio to your computer serial port. A direct cable connection won't work and could damage the radio and/or computer serial port hardware. I use an RT Systems CT29A cable, sold for the VR-500. RT Systems sales staff may be contacted at  (Note: I am not affiliated with RT Systems).

Tsunetaka Mitsuyasu describes, in Japanese, his 2-transistor home made interface.

Stefano Sella IW3IBF describes, in Italian, a 2-transistor home made interface, but Rubens Monteiro Luciano PU2RML had to replace DZ1, the 4.7 volt Zener diode, with a 3.3 volt white LED acting as a Zener to make the circuit function properly with his VR-500.

Mr. Skinny uses a MAX-232 IC based interface.


Thanks to Dan Wanchic, WA8VZQ, for posting detailed information about the RDF file layout to the email list. Paul Martin, N8ULS, and others helped provide information required to enable the enhanced configuration and Narrow AM features.

tk500 is undergoing development. To download a beta test version, including source code, click on the appropriate link to the left.

Revised April 6, 2004