Pulsar EME manual

WSJT 4.6 User ’ s Guide Copyright 2004 by Joe Taylor, K1JT WSJT is a computer program for VHF/UHF co mmunication using state of the art digital techniques. It can decode signals propag ated by fraction-of-a-second reflections from meteor trails, as well as steady signals 10 to 20 dB weaker than those needed for conventional CW or SSB. Operating M[...]

Decoded Text Box Main Screen FSK441A mode Setup | Options Screen 2[...]

Example Files To gain some familiarity with the op eration of WSJT, use the program to decode some example files provided with the stan dard installation. Hit function key F7 to choose FSK441A mode, and select Open from the File menu. Navigate to the RxWavSamples folder in your WSJT home directory and open the file record ed from W8WN. W hen this [...]

Basic Operating Instructions Note: further details on commands in boldface may be found in the alph abetical list starting on page 15. WSJT uses timed intervals of transmi ssion and reception. By convention FSK441 and JT6M use 30 s periods, while JT65 always uses 60 s intervals. To prepare for making a QSO, enter the other station’s callsign in t[...]

button down to select any desired region. As in FSK441, with marginal signals you should experiment as necessary for best decoding. JT6M can work with signals m any dB we aker than those required for FSK441. You will som e times find that clicking on a smooth green line, even where nothing was heard and nothi ng can be seen, causes callsigns or oth[...]

received signal, a necessary step toward d ecoding the message. Proper synchronization is indicated by a sharp upward spik e in the red curve and a broade r peak on the blue curve. Horizontal locations of the peaks correspond to the frequency and time offsets, DF and DT, between transmitter and receiver. EME QSOs have propagation delays o f about 2[...]

Standard QSO Procedures Difficult contacts become easier if you follow st andard operating practices. For minim al QSOs, the recommended procedure is as follows: 1. If you have received less than both calls from the other station, send both calls. 2. If you have received both calls, se nd both calls and a signal report. 3. If you have received both[...]

You will need a method of setting your com put er clock to an accuracy of one second or better, and keeping it set. Many operators us e an internet clock-setting program, while others use a GPS or WWVB receiver. Solar and Lunar Data The light blue text box in JT65 and EME Echo mode presents data for tracking the moon, measuring sun noise, tuning yo[...]

EME Echo Mode EME Echo mode (see picture on next page) is designe d to help evaluate the performance of your station for moonbounce communi cations. Activate it from the Mode menu or by pressing function key F9 . Aim your antenna at the moon, pi ck a clear frequency, and toggle the Auto button to ON . The program will then start cycling through th [...]

Information in the text box gives the numb er N of completed echo cycles, the average Level of receiver background noise in dB, the average echo streng th Sig in dB, its measured frequency offset DF in Hz (after correction for Doppler shift), its spectral Width in Hz, and a relative quality indicator Q on a 0–10 scale. Background nois e level is [...]

Measure mode, with preamp turned on and off repeatedly EME Calc Clicking the button labeled EME Calc at the lower left of the Echo-mode screen will pop up a utility program for predicting the s trength of your echoes from the moon. Enter th e requested quantities for your station and click Compute; if you enter par ameters for a DX station as well,[...]

transmissions lasting 30 seconds or longer will put more stre ss on your final am plifier than SSB or CW operation. If this would cause th e amplifier to overheat, you should take appropriate action: reduce power or add another cooling fan or blower. Menus and the Setup | Options Screen File Open: read and decode a previously recorded fi le stored [...]

NA/EU Defaults: insert default templates for ge nerating standard FSK441 and JT6M messages. The templates can be edited, for example to append a suffix or prefix to a callsign, or to properly format a contest exch ange. For example, if G4FDX changes the template for m essage TX1 to read “ %T W9/%M ”, the message “ K1JT W9/G4FDX ” will appea[...]

Alternate PTT Logic: activate slightly different progr am logic for controlling your T/R switching via the COM port. (A few combinat ions of hardware and operating system drivers seem to work better with this option checked.) Tx Mute: mute the transm itter. Use with Auto ON to monitor one side of a QSO. Enter new “To radio” callsign: clear the [...]

Alphabetical List of On-Screen Controls Note: some controls are visible only in certain operating modes . Add: causes the displayed callsign and grid locat or to be added to the database file CALLSIGN.TXT . If an entry for this callsign already exists, you will be asked if you want to replace it. AFC: activate automatic frequency contro l in JT65 d[...]

Measure: initiate a series of noise power measurem ents. Monitor: start a series of recordings, perhaps to monitor a calling frequency or to copy two other stations engaged in a QSO. Play: play most recently decoded file thr ough sound card speaker ou tput. This button functions much like the “Play” button on a cassette recorder. QRN: adjust to[...]

Grid: after a successful Lookup , displays the six-digit grid locator of the callsign in the To radio box. You can also enter a grid locator manuall y. If only four digits of the locator are known, add a space. Report: e nter the signal report you wish to send to the other station, then click Gen Std Msgs . RIT (Hz): your receiver RIT setting in Hz[...]

Further Reading 1. A separate WSJT 4.6 Technical Manual (in preparation) provides technical specifications and details on how the WSJT modes work. The Technical Manual will be posted at http://pulsar.princeton.edu/~joe/K1JT , the W SJT home page, when available. 2. In the meantime, technical inform ation can be found in the Version 3.0 WSJT User’[...]