To: Users and potential users of WSJT From: Joe Taylor, K1JT Many thanks to all of those who have thoroughly tested several beta releases of WSJT, the new program for amateur meteor scatter communication. I am pleased to announce that version 1.0 of WSJT is now available for free download at http://pulsar.princeton.edu/~joe/K1JT and soon also at the European mirror site http://www.vhfdx.de. An updated manual for WSJT v1.0 is in the works but not yet packaged with the program files. Until the new manual is ready, the following notes will have to do. They identify the most significant enhancements to the program since v0.93.2, and should be read in conjunction with the manual for v0.93.2, available on the WSJT web page as WSJTHELP.HTM. NEW FEATURES IN WSJT VERSION 1.0 -------------------------------- 1. A number of enhancements have been made to the decoding algorithms for both multi-tone and single-tone messages. Sensitivity and accuracy are better than before, and there is much better rejection of all non-FSK441 signals, including QRN. 2. A new "Setup|Options" menu item brings up a panel for the entry of infrequently changed parameters. These include your callsign and grid locator; the offset between your computer's clock and UTC; values for RXDelay and TXDelay, in seconds; the station identification interval; and individually adjustable amplitudes for the four FSK441 tones. In addition, standard templates are offered for both North American and European style HSMS exchanges. The templates can be edited if you prefer your messages to be slightly different. 3. A text box on the main screen is provided for the grid locator of the other station. Enter a 6-digit locator, or four digits followed by a space, and the program will report the distance and azimuth bearing from your QTH. It will also tell you the optimum elevation angle for meteor trails at 100 km height and the azimuths of the "hot spots" on either side of the great circle bearing, and it will identify which of the hot spots is the better one for random meteors at the current time of day. 4. Beneath the "To Radio" text box is a command button labeled "Lookup". Click on this button and WSJT will attempt to look up in a local database essential information about the station callsign in the To Radio box. At present the only information fetched is the grid locator. A short database file CALLSIGN.TXT, to be located in the WSJT installation directory, is provided with information I quickly put together on some of the more active North American stations at the present time. You can edit and maintain the database for your own purposes, following the format shown. Use Windows Notepad for this purpose, or another editor or word processor that will save the file as pure ascii text with no formatting information. Enter information in the same columns as shown in the example file. 5. The waterfall spectrogram is now presented in pleasing "living color". 6. Steady signals, weak or strong, will now usually decode well with a click of the left mouse button with the pointer in the plot area. 7. At the 147 characters-per-second speed of WSJT, even a brief ping may contain the entire transmitted message repeated several times over. Additional signal-to-noise ratio may be gained by averaging the message information over several repetition cycles. WSJT now attempts this averaging automatically -- and if it succeeds in finding a repetition period, it presents the averaged message by default. To disable the averaging and see the full decodable content of a ping, click on the ping using the *right* mouse button. 8. Any of the supported FSK441 characters may now be used in the "To Radio" box, so you may enter such things as QRZ?, K9KNW/C6A, or K9EA/VE3. The first part of such a construction (e.g., QRZ, K9KNW, or K9EA) will be used as the prefix for the recorded file names. 9. Pressing Generate Std Texts now automatically sets the TX message number to 1, the expected DF to 0, and the Tolerance to 400. SETTING INDIVIDUAL TONE AMPLITUDES ---------------------------------- First and foremost: the default equal-amplitude settings seem to work well with most radios and soundcard-to-radio interfaces. If you are using a recorded voice of CW identification file (file ID.WAV in the WSJT directory) you may wish to reduce all four amplitudes to, say, 0.700 or 0.500 so that the recorded station identification more nearly matches the amplitudes of the WSJT tones. If your power output varies by more than about 20% among the four FSK441 tones, you may wish to adjust amplitudes of the generated audio tones individually. Amplitude settings can vary from 0.000 (off) to 1.000 (full amplitude). They refer to voltage, not power. So if your measured powers are 100, 100, 100, and 200 Watts in the four tones, you should set the amplitude numbers to 1.000, 1.000, 1.000, and 0.707 (because 0.707 squared is equal to 0.5). STILL TO COME ------------- My next job is clearly the manual, but I have not forgotten the PUA-43 mode. As always, bug reports and items for the "wish list" will be welcome. Please send them to k1jt@arrl.net. -- 73, Joe, K1JT