With each daytime grows an amount of stations, working PSK31.
For functioning (working) in this mode sufficiently have tranceiver, computer with the sound card, and several connecting wires between the computer and tranceiver.
New mode [digicom], appeared suddenly beside radioamateurs in past  year, capable to fill a gap between RTTY on the one hand and other hight-technology modes on the other hand. This mode PSK31, based on SP9VRC ideas and oriented on using the cheap kits DSP and available software. In him modern DSP-a technology is used for ensuring a possibility of an ing brightenned by QSO, in accordance with the transmission-acceptance given on the type "keyboard-screen". Signal frequency Band in the mode PSK31 much already, than in any other mode of data base communications, due to that it ensures a possibility of relationship with more low signal levels in overbusy for a present-day day amateur ranges.
Main idea of mode PSK31 consists in that that manipulate by the signal is executed by the shift of phase carrying instead of the shift of its frequency. Band of frequencies of signal is herewith defined only by the velocity to manipulates, rather then value of shift of frequency in the amount at the speed of manipulates. Chosen velocity to manipulates in 31.25 Baud stipulates a band of frequencies the whole in 31 Hzs instead of 300...500 Hzs for other modes. To the Account of using an alphabet of code, like alphabet of code Morze with short codes for the most often meeting symbols, mode PSK31 ensures a send rate of text of order 50-ty of words at a minute. When using in the transmitter and receiver of the most narrow-band filters, what only possible, efficiency of mode PSK31 even without automatic correcting the errors certainly exceeds efficiency of any other mode and ensures an additional advantage for brightenned by QSO, cocosting in that that even under «collapses» aflat signal efficiency of mode falls much small. On radioroutes, where more often happen packet type errors, than evenly distributed single malfunction, program PSK31SBW can be switched in the mode of using an verification`s code at the transmission and corresponding decotwitch Viterby in the receiver. This mode QPSK with 4-th phase shifts instead of two, but band of frequencies, occupied by the signal, and send rate of symbols stay former [as with signals BPSK ]. The Price ensured when raising noise-immunity - more hard requirements to stable carrying frequencies and delay in 640 мс when decoding [symbols].
On these pages You will find other interesting references. want Successes in PSK31!
In text used fragments from program description translation PSK31SBW, done RV3DBL and RA3DOA.
Here is some foto QSL-card for QSO on 14 MHz band on PSK-31
This QSO made on TRCVR ICOM-718 (30-40 watts power in this digital mode) and EH antenna (50 centimeters long)
Made is 2000 QSO in one year on PSK-31 and 100 coutry and all continents.