Amateur Radio Software

A range of specialized software and hardware, mostly related to MEPT operation


Here we have a collection of software and some hardware for a range of auxiliary purposes. There is software for:

Sound File Generation
SSB transmitters can easily be used for MEPT transmission. This is an attractive approach of extreme simplicity for those not able or prepared to build dedicated MEPT hardware. To do this, however, you generally need software to generate a sound file that can be transmitted. For many years the only way to do this was using the DF6NM Chirppix utility, a DOS program, but there is now a new method which is compatible with 64-bit Windows computers.

How to make WAVs

MEPT Controllers
VMEPT Controller is a simple application designed to operate a Manned Experimental Propagation Transmitter, allowing visually detected slow very low power transmissions (QRSS) to be generated automatically by PC. It sends an audio pattern and also controls the SSB transmitter PTT via a COM port. It is designed to work with .WAV audio files, made either with DF6NM Chirppix, or ZL2AFP MEPT Controller (see below). The program allows adjustable transmit and receive duration based on these .WAV files. Designed and coded by ZL2AFP.

Introduction to VMEPT Controller controller software

AudioMEPT is similar application, which uses WAV files generated by Chirppix or ZL2AFP MEPT Controller, but has the advantage of fixed and accurate 10-minute transmission frames and precisely (to the second) timed transmission start, making it practical to use WAV files for WSPR transmission as well as for visual (QRSS3) transmissions, in fact (if both modes are added to one file), it can do both sequentially. It was designed by ZL1BPU and coded by ZL2AFP.

Introduction to AudioMEPT Controller
AudioMEPT MEPT controller software

MEPT Controller has a similar purpose, but has the unique aspect that the patterns are designed directly on the screen - it's 'WYSIWYG'. MEPT Controller is extremely versatile, and can be used to generate DFCW for QRSS60 just as easily as QRSS3 image patterns. Importantly, it only transmits one tone at a time, so can be used with non-linear transmitters. It also generates nicely shaped .WAV files if you wish. Designed by ZL2AFP.

Introduction to WYSIWYG MEPT Controller
ZL2AFP MEPT Controller software

ANDROID MEPT Controller by Andrew ZL1WJQ is a really simple program which will run on most Android devices, so you could recycle that old phone or tablet for MEPT use! Like WAVMEPT, it uses a .WAV file. Android MEPT is just 28 lines of code, written for RFO BASIC!, which you download and install on your device.

Introduction to RFO BASIC! (and download)
Android MEPT controller software and instructions

PTT Transmitter Control
PTT Remote is a PTT control for any software which does not (thanks to Window$) have direct access to COM ports for PTT control. PTT Remote is a simple program which you run and configure before the other program, and when it sees the presence of a file named 'TX.txt', it turns the transmitter on, and when the file is removed it turns the transmitter off. It has very fast response. PTT control

PTT Toggle is a manual PTT control for any program not itself equipped for PTT control.

PTT PTT control

VOX PTT is a simple one-IC design which provides PTT control from the audio output of a Tablet or PC which lacks a serial port which can be used for PTT control. You connect the sound output (headphone socket) of the computer to the transmitter, and also to this circuit.

The design has three op-amp stages: a high gain amplifier, a slicer/detector, followed by a diode sample and hold circuit, then a buffer used to provide high impedance to the timing circuit. The trim pot sets the sensitivity. The output of the buffer drives a keying transistor suitable to operate the PTT of most rigs. The keying transistor will handle 12V at 100 mA.

The attack time of this design is about 200 ms, and the delay (at end of transmission) about three seconds. To adjust the delay, change the 33k resistor and/or the 47 µF capacitor.

VOX PTT Circuit (full size)

Copyright © Con Wassilieff and Murray Greenman 2004-2009. All rights reserved.