Syncing the clockĪs mentioned earlier, it is vitally important that your computer clock is accurate, as this governs when WSPR starts each transmit or receive period, and nothing will be decoded if your clock is more than a couple of seconds out. This is a random probability, so that two stations which start off at the same time with the same probability will not always transmit in the same segment.
#Jt65 transceiver software#
Most operators set the software to transmit once in every four or five two-minute segments. It is not necessary to transmit at all, so this is an activity that even SWLs can participate in - and many do. How much transmitting you decide to do is up to you. The WSPR software incorporates both a receiver/decoder as well as a transmitter. Forward error correction is used to improve the chances of copy even under adverse conditions while eliminating false "spots". The beacon transmission contains the transmitter's callsign, locator and power (in dBm.) The data is encoded to reduce the number of data bits needed, with the result that only standard callsigns can be used - no prefixes, suffixes or special calls. It is important that transmitters and receivers are in sync, so one of the fundamental pre-requisites of success with WSPR is an accurately-set computer clock. The bandwidth occupied is only about 6 Hz, so many stations can operate within the 200Hz WSPR window without interference.Įach MEPT-JT transmission lasts for just under two minutes, and starts at the beginning of each even-numbered minute. In fact, some people have mistakenly thought that the software wasn't working because they listened to the signal and heard what sounded like a pure tone, with no modulation at all. The signal is frequency shift keying (FSK) with a very small shift and a very slow rate.
#Jt65 transceiver license#
Just how "hands-on" you need to be when operating WSPR is a matter between you, your license authority and your conscience, but some people leave their WSPR beacons running 24/7 and some of that time, one assumes, they must be asleep. So this is something you can do when you are otherwise engaged and not able to get on the air and make normal QSOs. The software logs every transmission you make, as well as all the "spots" (decoded MEPT-JT signals) received. Once set up, operation of WSPR is completely automated. In fact, some MEPT enthusiasts discourage the use of the term "beacon" because beacon operation without a special permit is prohibited by some licensing authorities. It is not necessary to obtain a special dispensation to operate a MEPT station because you are present while it is in use, just as you would be when using CW, SSB or another data mode. The "manned" aspect of MEPT simply relates to the operator's license conditions. The content of a transmission is determined - as with many other weak-signal QRSS modes such as EME (moonbounce) - by literally reading the dots and dashes as they are displayed on the waterfall. Their very weak signals are copied visually using software called a "grabber" - a horizontal waterfall display capable of detecting and highlighting signals well below the noise threshold. MEPTs are very often simple home-built QRP transmitters that send beacon messages using very low-speed Morse (QRSS). The "JT" stands for Joe Taylor, while MEPT stands for Manned Experimental Propagation Transmitter. It uses a transmission mode called MEPT-JT. WSPR is a software application written by Joe Taylor, K1JT, a Nobel Prize-winning Princeton physicist. WSPR stands for Weak Signal Propagation Reporter, but it's pronounced "Whisper" - quite an appropriate name as it is all about sending and receiving signals that are barely audible. You can analyze past signal reports to see the effect of seasonal propagation changes or antenna improvements. If you left WSPR running while you were doing something else, you can also search the database to find out later where your signals were received during the day. Because participating stations usually upload spots that they receive in real time to a web server, you can find out within seconds of the end of each transmission exactly where and how strongly it was received, and even view the propagation paths on a map. It enables your radio transceiver to transmit beacon signals, and to receive beacon signals from similarly-equipped stations in the same amateur band. WSPR is a piece of software that enables you to participate in a world-wide network of low power propagation beacons. If this is an aspect of radio that fascinates you, then you'll enjoy using WSPR. Short wave radio propagation is never completely predictable, and can often surprise you. One of the things that makes communicating with amateur radio more fun than using the Internet or the phone is that you never know where your signals will be received.
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