Uhmm! A Multi-Tone Frequency Shift Keyed Program eh!
by Ernie Mills, WM2U.
Please print this article and use it as a hand out at Club talks and lectures

So what do we have here eh? Throb is an experimental mode written by Lionel Sear, G3PPT. It uses a possible 9 tones spaced 8 or 16 Hz apart, which gives a bandwidth of 72 or 144Hz respectively. It has three transmission speeds, 1,2 and 4 Throbs/sec which give data rates of 10, 20 and 40 wpm respectively. The 1 and 2 Throb/sec speed use a tone spacing of 8Hz, bandwidth 72 Hz and the 4 Throb/sec speed  uses a spacing of 16  Hz, bandwidth 144 Hz.  Download this software from here.
There are almost no setup or configuration worries to go through. Remember this is an experimental mode at present so don't look to far for any bells and whistles eh!

Screen shot of main window

The Main Window 

Setup Menu

Screen shot of Throb setup menu

k! lets go through the menu buttons at the top.  The FILE menu only has one option; Exit.  The SETUP menu is as described at left. The next option is the HELP menu. Clicking on this makes the Help file pop up and it is strongly recommended at this point that you print it off and read it through. The last option is the ABOUT button. Yep! this will give ya! the software version.
The program boots up with a default speed of 2 Throb/sec speed. First off click on the setup menu. This is shown at left. Enter your call sign. This is a must if you want the CW ID to work and also some Macro keys use this for the buffers. Select you active com port and I found that I needed to set the PTT Delay to ON otherwise I would get no PTT switching. Not sure why this is yet!

The program is very demanding on CPU time. It is recommended that screen savers and other processor intensive programs should be suspended while running Throb. If you experience jerkiness in the operation recheck for programs running in the background. Otherwise you have no choice but to talk the XYL into a new, faster, computer :)

              Operating Quick Tips
Fire up the program and set the configuration as detailed above. ie call sign, com port. etc.
Make sure your computer is interfaced to the radio. If you need help on this check out my Interfacing  page.
Switch on the rig and observe that signals between 800 and 1100 Hz appear on topmost waterfall indicator. Back off on the audio if you see red lines on the waterfall.
Click the Test On button and observe the test signal. If the signals marks are very faint or difficult to see, adjust the Waterfall sensitivity control at the right. Move the curser onto the test signal and click on the very center. The red line markers should now straddle the signal. Practice this as the most difficult thing with this program is tuning in the signal. The test signal is at 900Hz. 

    Hardware  Requirements
  • A computer with Windows 95©, Windows 98©, or Windows NT©.
  • At least a Pentiumô 60 processor (P133 prefered)
  • A 16 bit sound card that works with windows.
  • A HF transceiver.
  • Sound card interfacing and PTT control.

The profile or shape of the signal will be seen in the graphic window on the left side display below the waterfall indicator, and the red line shows where the sampling of the signal starts. If you switch the autosync off you will be able to position the red bar manually.
The small graphic window to the right shows the intensity of the decoded tones in green. In operation you will see one or two tones but if more appear, synchronization is out so move the red bar as described above.
Below this are two text screens. This is a sideband sensitive mode.  What you have here is a display for both LSB and USB shown simultaneously, hence during reception of a signal, only one will make sense. During a QSO, click on the one that you can read and it will expand at the expense of the other one.
Now click the Tx On button. The PTT should fire up the rig and you should hear the transmit signal idling. Type something in the Tx window. It will appear in the right hand memo screen before it is shifted out. You will notice that  two or three idling pulses are sent out ahead of the data! This is really good for the receiving station to click on for accurate tuning.
OK, finally a word on the Macro buttons. The CQ and QRZ buttons are self explanatory. The Macro1 and Macro 2 buttons appear to be fixed text. I have not figured how to change them  yet :)  They work only when a call sign is entered into the Other Station box and the text sent is Other de YourCall.   Now the 1.TXT, 2.TXT, and 3.TXT are programmable Macros. Simple write buffers in WordPad and save them, in the same directory as the Throb.exe and name them 1.txt,2.txt and 3.txt.  
Hey! would you believe that is all there is to it eh!  Get to it then and I hope to work you with Throb.

Since this page was written Throb2000 has come out and it has a New Look. Checkout this web site for details and downloads.   

  Good luck, enjoy and I see you in there.73 Ernie (WM2U)