binary phase shift keying the sussex county amateur radio …二进制相移键控苏塞克斯县业余无线电…

1、Write-Log, Binary Phase Shift Keying (PSK31), Digital Panoramic Tuning (DigiPan) and Radio Set-Up.,Write-Log,Click her to open this box. Set the frequency and mode before operating. Click FSK for PSK-31 Contacts. Please try not to forget to avoid unnecessary editing.,Write-Log,Super Check Partial,En

2、ter Call, Operating Class and Section. Tab over by using Space Bar,Click Contest then Multipliers,Click Window then Super Check Partial,“Alt W” Clears this entire row. Left, Right Arrows and Backspace allows for editing.,Click Window then Band Summary. Networking will display all Stations.,Logged St

3、ations,What is PSK31?,PSK31 was developed by Peter Martinez (G3PLX) and introduced to the amateur community in December 1998. PSK31 was also known as Varicode Mode (Variable Number of Bits) From the perspective of the transmitter, this amounts to little more than somebody whistling into the micropho

4、ne. PSK31 rapidly shifts the phase of the audio signal between two states. These shifts serve the same function as two FSK tones traditionally used by RTTY. Instead of shifting frequency were shifting phase. PSK31s bandwidth of 31.25Hz was chosen because a normal typing speed of about 50 words per m

5、inute requires a bit rate of about 32 bits per second (1Bit/Hz). PSK31s 31.25Hz can be derived from the 8KHz sample rate used by the DSP chips in computer sound cards,What is PSK31?,Frequency Domain,Time Domain,PSK 31 vs. RTTY,The chart at the right shows the BIT Error Rate (BER) as a function of Si

6、gnal-to-Noise ratio in a noiseless environment. Note: BER is the number of BITs received in error. For example, a BER of 10-5 is 1 erroneous BIT received in error out of 100,000. For Signal-to-Noise (S/N) ratios greater than 10 dB, PSK-31 is virtually error free. S/N=10Log(Power of the Signal Power

7、of the Noise). In other terms, if the noise level is 1uV then you need 3.16uV for 10dB S/N At poor S/N ratios the BER of PSK-31 is five times better than RTTY Note the curve that represents QPSK-31.,PSK31 - Real World Performance,The power in a PSK-31 signal is concentrated in a 31.25 Hz bandwidth v

8、ersus 250 Hz (BW not frequency shift) for RTTY and 3300 Hz for SSB. Assuming 100 watts of transmit power, the PSK-31 signal has 3.2 watts/Hz vs. 30mW/Hz for SSB. If a signal provides 20 dB S/N ratio at the receiver using SSB, the same S/N ratio is achieved with 8W using RTTY and only 1W using PSK-31

9、! Lower Case characters are more efficient than upper case due to Varicode (not to be confused with ASCII or Binary code). PSK31 characters contain a variable number of bits. Lower-case PSK31 characters have fewer bits than their upper-case equivalents, so lower-case text transmits faster and decode

10、s better For example, the letter “a” has the Varicode 1011. The capital letter “A” has a Varicode of 1111101. The letter “a” has four BITs,FYI: The better alternativeQPSK31,QPSK31 has FEC convolutional code; lowers the number of errors Forward Error Correction (FEC) is when redundant data is sent 90

11、0 out of phase with the primary data stream. A Viterbi Decoder decodes the bit stream and estimates likelihood the data is correct or not. If not it corrects the error. Under very poor propagation conditions (like now); 1 out of 5 PSK-31 characters get thru compared to 1 out of 2 QPSK-31 characters.

12、,DigiPan Signal Channel,Right Click to put cursor on the signal you want to receive.,This is the Transmit Window,This is the Receive Window,DigiPan Multichannel,CQ,Click Call,Goes here,3A NNJ,Preset FD Macros,IMD,Radio Set Up,PSK-31 is a 100% duty cycle mode. For all radios reduce power by 50% Turn

13、Audio Compression OFF With MIC Gain very low and power very low click T/R button on DigiPan to Transmit Adjust MIC gain so ALC has little or no needle movement This is to prevent Inter-Modulation Distortion from being transmitted. Digital waveforms inherently produce IMDs. Adjust power to 50W (typical). Re-adjust MIC gain for little or no ALC needle movement Re-adjust