WSPR Distant Whispers. 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. Short wave radio propagation is never completely predictable, and can often surprise you. If this is an aspect of radio that fascinates you, then youll enjoy using WSPR. WSPR is a piece of software that enables you to participate in a world wide network of low power propagation beacons. It enables your radio transceiver to transmit beacon signals, and to receive beacon signals from similarly equipped stations in the same amateur band. 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. 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. You can analyze past signal reports to see the effect of seasonal propagation changes or antenna improvements. What is WSPR WSPR stands for Weak Signal Propagation Reporter, but its pronounced Whisper quite an appropriate name as it is all about sending and receiving signals that are barely audible. WSPR is a software application written by Joe Taylor, K1. JT, a Nobel Prize winning Princeton physicist. It was first released in April 2. It uses a transmission mode called MEPT JT. The JT stands for Joe Taylor, while MEPT stands for Manned Experimental Propagation Transmitter. MEPT is not something specific to WSPR. MEPTs are very often simple home built QRP transmitters that send beacon messages using very low speed Morse QRSS. 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. 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. The manned aspect of MEPT simply relates to the operators license conditions. 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. 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. Once set up, operation of WSPR is completely automated. The software logs every transmission you make, as well as all the spots decoded MEPT JT signals received. So this is something you can do when you are otherwise engaged and not able to get on the air and make normal QSOs. 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 2. Principles of operation. WSPR itself does not use slow Morse. Check Serial Port Status Linux Wine' title='Check Serial Port Status Linux Wine' />The signal is frequency shift keying FSK with a very small shift and a very slow rate. In fact, some people have mistakenly thought that the software wasnt working because they listened to the signal and heard what sounded like a pure tone, with no modulation at all. The bandwidth occupied is only about 6 Hz, so many stations can operate within the 2. Hz WSPR window without interference. Each MEPT JT transmission lasts for just under two minutes, and starts at the beginning of each even numbered minute. 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 beacon transmission contains the transmitters callsign, locator and power in d. Bm. 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. Forward error correction is used to improve the chances of copy even under adverse conditions while eliminating false spots. WSPR for Linux. As mentioned above, getting WSPR to run under Linux is quite a challenge. The GUI version described here does not run under wine, although the older. The WSPR software incorporates both a receiverdecoder as well as a transmitter. How much transmitting you decide to do is up to you. It is not necessary to transmit at all, so this is an activity that even SWLs can participate in and many do. Most operators set the software to transmit once in every four or five two minute segments. 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. Syncing the clock. As 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. If you are using Windows XP, open the Date and Time window in Control Panel and select the Internet Time tab. There, you should see an option to synchronize the clock using an Internet time server, time. Select this option, and do an immediate sync to see if it works. If you have a radio controlled clock or a GPS you can compare your computer clock with it to see how accurate it is. Do this every day over a period of a week. Windows only synchronizes the clock with the time server once per week, and many computer clocks drift several seconds per day which is just not good enough for this application. If you need to make Windows synchronize more often then here is a link to a utility untested by me that allows you to change the time sync interval. Alternatively if you have a permanent Internet connection you can disable the Windows time synchronization altogether and use NTP for Windows. Transceiver setup. WSPR needs connections between your computer sound card and your radio transceiver in order to decode received beacon signals and send your own transmissions. It also needs to be able to control your transceivers PTT using the serial port RTS control line, unless you want to use audio VOX. If you are already set up to use data modes such as PSK3. However if you have a full serial connection between the computer and radio in order to allow full computer control, your data mode software may be using computer commands to control TXRX switching. WSPR only knows how to use RTS to control PTT so you may need to enable this within your transceivers configuration menu or make a transistor switch to interface between the PTT and the RS 2. RTS signal. See here for more information about interfacing a computer and transceiver. Basic Linux kernel documentation The following are Linux kernel related documents, which you should take a look at before you post to the linuxkernel mailing list. What is the best way to access a serial port from VBA I have a need for some of our sales reps to be able to send a simple string over the serial port from an action. Complete Technical Acronyms, Glossary Definitions for PC, SAN, NAS, QA, Testing, HDTV, Wireless, Linux, Embedded, Networks, Video, Digital, pharma, Unix, Video. If you cant easily use a serial port to control PTT then you can try VOX. Because MEPT JT is a very narrow band mode, it is desirable though not essential that your transceivers dial calibration is accurate to within at least a few Hz. If you dont have any accurate frequency calibration equipment then an easy way to do this is to tune in some AM short wave broadcast stations in SSB mode, while monitoring the received audio using a spectrum analyzer program or data mode software with a waterfall display, and using this to measure the frequency of the carrier heterodyne. Short wave broadcast stations transmit on exact multiples of 5. Task Scheduler How To Edit A Taskbar here. KHz, and their frequencies are usually accurate to within a Hz or two. Tune 1. KHz above or below the frequency the short wave station is supposed to be on for example, 5. MHz or 5. 9. 86. 00. The source for information on Linuxunix Smart Homes.