ZL2AFP WYSIWYG MEPT Controller

Introduction

ZL2AFP MEPT Controller is a simple but unusual application, which uses the PC sound card to generate Visual Manned Experimental Propagation Transmissions (V-MEPT). The unique thing about it is that the script files used to transmit the message are made on-screen, so you see what will be transmitted. The program generates only one tone at a time, so is useful with non-linear transmitters. It provides transmitter control in addition to generating the sound for the transmitter.

The latest version (V1.09) is also able to save the patterns in ZL1BPU script format (used by several synthesizer applications), and also able to save the output as a .WAV audio file, which can then be played by an audio player controller, such as AudioMEPT.

Since it can be used at the same time as a Spectrogram receiver program such as ARGO, the periodic transmissions generated by MEPT Controller V1.09 allow you to transmit and receive alternately and thus actively participate in the 'QRSS Knights' V-MEPT community. It will run both fast and slow - 12 WPM Morse, or QRSS60, and is useful on LF, MF, HF and VHF. Timing is very accurate - quite sufficient for receiver 'stacking' techniques.

Used in conjunction with a receiving program such as ARGO, you can set your transmission length to (for example) five minutes, then listen for five minutes, then repeat.

Download

ZL2AFP MEPT Controller V1.09 (130kb)

Installation

Simply unzip the archive into a suitable folder on your computer. It contains just one small file, the executable, along with this help file and associated images.

Create a shortcut to the MEPT Controller v109.exe executable, and drag it onto the desktop for easy use.

Setting Up

Unlike the VMEPT Controller, which requires considerable preparation, with ZL2AFP MEPT Controller you can be in business and on air in minutes.

Run the executable. It will tell you there's no PTT port set up (every time it starts), so click on PTT in the menu, select PTT (no other choice!) and enter your PTT COM port. The connections required are much the same as any digital mode - it will work with RTS or DTR. If you plan only to use the program to make .WAV files (see later), just select any valid COM port.

The program presents you with an empty graph field, with a menu above and a series of setup controls below, and below that again, more real-time controls and finally a blue progress window.

WYSMEPT Control Center

In the example above, you can see that the graph field has already been filled in, in this case with dots for a QRSS3 dual mode (MT-Hell and CASTLE) transmission. Note the time scale (in number of dots) shown below the graph. It is important to keep track of the number of dots to be transmitted in order to control the message length and the delay until it is transmitted again.

All you do to get started, is to click on some of the squares in the graph to set a blue dot in each, working from left to right. The grey line down the middle represents the nominal transmission frequency, and this and seven frequency slots above and below it can be selected for transmission in any of the time slots. Click a few spots - you'll notice that you can't have more than one blue dot in each time slot. If you want a different frequency, just click in a different place, and if you want no transmission at that point (e.g. to erase the dot you've placed), right click on the dot.

If you want a single-frequency (CW) pattern, click only along the grey dotted line.

Once you are happy with your pattern (or even if you aren't, as it's easily changed), then set the transmission parameters in the setup controls. Note that from v1.08 you can no longer change the pattern on the fly, i.e. while transmitting, or rather, if you do, the changes won't be implemented until the next transmission (specifically the next time you press Turn On).

• The Dot length (ms) sets the length of each element. For example use 3000ms for QRSS3, 100ms for hand-speed Morse. Press the OK button when done. For mixed mode, where one mode requires longer elements than the other, set the dot length for the shorter elements, and simply use multiple dots on the same frequency for the longer elements. There will be no transients between dots.
• Set the Number of dots to the same as or slightly more than the length of the message. Once this point has been reached, the program drops the transmitter PTT. Press the OK button when done.
• Set the Freq spacing (Hz) as appropriate for the mode intended, say 10Hz for QRSS3, 0.5Hz for QRSS30. For single-frequency Morse, the default 10Hz will do. Press the OK button when done.
• Set the Centre frequency (Hz). On upper sideband, this frequency, plus the 'dial frequency' of the SSB transceiver or transmitter will be the carrier frequency of dots on the centre line in the graph. Press the OK button when done.
• Set the Repeat (in dots), which defines the total time between transmissions. Once this time has expired, PTT is activated and the transmission starts again. For example, with 1000ms dots, a 50 dot message and a 'Number of dots' of say 60, setting 'Repeat' to 100 will result in the transmitter being deactivated for 10s, and a total message repeat every 60 seconds. Press the OK button when done.

It is important to press each appropriate OK button when done, in order for the new value to be remembered. If you wish to clear all the settings and start again, press the Reset button.

At any time, you can save the pattern you've made as a script file. This is a simple text file, and can be reloaded for next time. In addition to saving the pattern, all the other parameters (dot length, frequency spacing, centre frequency etc) are also saved. Use Menu/Save to File to save the pattern, and Menu/Open File to read in a saved file.

Making WAVes

You can also save the pattern to a .WAV format audio file for instant transmission. The file will be quite large, but has the advantage that it can be played by any audio controller or media player, on any operating system, and can be converted to a compressed format such as .MP3. When you press Turn On, the program will 'render' the dots you have placed on the screen into a sound file in memory, complete with nice soft edges to the tones, constant zero phase start and stop and no offset during silence. This ensures that the transmission will be very clean with no clicks or thumps.

At present this is the only application available anywhere for making audio pattern files which will operate on 64-bit Windows computers.

There will be a delay while the rendering process takes place. Unfortunately this happens every time you press Turn On. During this time a progress bar will show in the program banner (at the top of the window). Once this rendering has taken place, the transmission will start. To subsequently save the audio as a .WAV file, you MUST press Turn On first, even if just for a few seconds, before pressing Turn Off again. Then use File/Save as .WAV to save the file.

ZL2AFP MEPT Controller V1.08 is not able to play stored .WAV files. For that you should use AudioMEPT or VMEPT Controller.

Hint:
It's a good idea to save the script or audio file with a name that reflects the parameters (mode, speed, centre frequency) so you don't have to load each one to find out what it is!

Both the memory image and the subsequently stored .WAV file have soft-edged thumpless audio.

Operation

It is a good idea to run ARGO or similar, and set up for reception on the band of choice, to make some test transmissions to yourself, in order to become familiar with the program, and to determine that your messages are readable. For checking read-by-ear Morse, just listen to the audio from the computer sound card.

There is no need to describe here how to set up for digital mode operation with an SSB transmitter - the process is the same as most other digital modes.

Set the SSB transmitter to the desired frequency (on USB, the transmission will be the sum of the dial frequency and the nominal audio centre frequency set above).

Check that in the menu you have set the PTT com port, and set the appropriate sound card selection. The menu also allows you to set the sound card and select the mixer levels. By the way, the PTT control works just as well with USB serial adaptors.

Start the transmission with the Turn On button, and check that the PTT is activated, and that tones are soon emitted by the transmitter.

A PTT status message appears at the bottom right of the window. As normal, you will need to set the sound card audio level for an appropriate transmitter power. This can be done with the Output level slider.

Once the program is running, the blue progress window, which shows all the message to be transmitted, has a small green progress bar above it, slowly moving along. At the far right a smaller window shows the total elapsed time in the message repeat interval, which may be much longer than the message, if desired.

If you change the dots while transmitting, or change any of the parameters, these changes are not picked up immediately, or even at the start of the next transmit cycle. This includes, in addition to the actual pattern, the Dot Length, Number of dots, Frequency spacing, Centre frequency Repeat and Output level. Changes will only be picked up the next time you press the Turn On button. If you want to use the changed parameters RIGHT NOW, stop the transmission and restart it.

Once transmitting, the Turn On button now becomes the Turn Off button, and stops the transmission process; clicking the red 'X' close button in the top right corner of the program banner closes the program.

Hint:
If you set 5, 10 or 15 minutes as the message repeat period, by counting and calculating the number of dots, and then start the program on a 'round' minute (xx:30 UTC for example) the message will repeat in a tidy and predictable manner for days on end.

Menu Items

File

File/Open pattern file selects an existing pattern file (.txt) for transmission

Save as pattern file .TXT saves the current pattern in a simple text file

Save as .SCP saves the current pattern in a text file in ZL1BPU format (used by several synthesizer controllers)

Save as .WAV saves the rendered audio in a high resolution uncompressed .WAV format file

Soundcard

Mixer opens the Windows Mixer applet so you can set levels etc (does not work on Win7/8)

Audio devices opens the Windows Audio Devices to allow setup

Selectsoundcard opens a small dialog which allows selection of the sound card to receive audio output

PTT

PTT opens a small dialog which allows selection of the appropriate COM port for PTT control

Advanced Features

There are some extra controls provided which will add interest to your message. The default output level is full power (0dB), which you set on the message graph with blue dots. While setting the message, if you click on one of the other buttons, -6dB, -12dB etc, the transmitter power will be reduced until you click on the blue button again. In this way you can make multiple power level transmissions, which is a great way to know what the reception margin is at the destination. For example, sending a series of diagonal lines in QRSS3 mode at different power levels can be very useful. Alternatively, draw numbers '0', '6', '12' etc as MT-Hell text!

If you wish to enter an extra-long message, you may need to use the slider control Move window in order to see what you are doing.

Here are some examples of reception of different patterns made using ZL2AFP MEPT Controller V1.08 and received on ARGO. The first two messages are multi-mode, while the third is just graphics. The first picture is the output of the example shown in the picture above, with five 6 dB 'power stripes'. The modes in the first two pictures are Sequential Multi-Tone Hell (left) and CASTLE (right).

No limit to ingenuity with ZL2AFP MEPT Controller V1.08!