Instruction/ maintenance manual of the product JT65 Pulsar
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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.
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.
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.
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.
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.
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.
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.
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 .
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.
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.
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.
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.
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.
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.
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.
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 .
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.
An important point after buying a device Pulsar JT65 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Pulsar JT65 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Pulsar JT65 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Pulsar JT65 you will learn all the available features of the product, as well as information on its operation. The information that you get Pulsar JT65 will certainly help you make a decision on the purchase.
If you already are a holder of Pulsar JT65, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Pulsar JT65.
However, one of the most important roles played by the user manual is to help in solving problems with Pulsar JT65. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Pulsar JT65 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
