Phase-shift keying (PSK) is a digital modulation scheme that
conveys data by changing, or modulating,
the phase of a reference signal (the carrier wave). PSK31 is the
first new digital mode to find popularity on HF bands in many
years. It combines the advantages of a simple variable length
text code with a narrow bandwidth phase-shift keying (PSK) signal
using DSP techniques. This mode is designed for "real time"
keyboard operation and at a 31 baud rate is only fast enough to
keep up with the typical amateur typist. PSK31 enjoys great popularity
on the HF bands today and is presently the standard for live keyboard
communications.
A second version having four (quad) phase shifts (QPSK) is available
that provides Forward Error Correction (FEC) at the cost of reduced
Signal to Noise ratio.
- How does it looks like?
| 160m |
1.838.150 MHz |
| 80m |
3.580.150 MHz |
| 40m |
7.035.150 MHz |
| 30m |
10.140.150 MHz |
| 20m |
14.070.150 MHz |
| 17m |
18.100.150 MHz |
| 15m |
21.070.150 MHz
21.080.150 MHz |
| 12m |
24.920.150 MHz |
| 10m |
28.080.150 MHz
28.120.150 MHz |
| 6m |
50.250.000 MHz |
| 2m |
144.138.000 MHz |
| 70cm |
432.088.000 MHz |
|
- More information you can find on:
|
Unfortunately there are a lot of stations with signals overdriven
like the following.
And unfortunately almost everbody gives a 599 report to this
station.
| PSK31 signal overmodulated |
 |
Please, don't give a 599 report to this station, which is
destroing other QSOs closed to this signal. The best report
for this signal is a 595 report with commends of a overdriven
signal.
That helps to keep clean the PSK spectrum from signals like
above. Most stations have no idea, how their signal looks
like.
|
| - READABILITY |
R5
R4
R3
R2
R1 |
95%+ Perfectly readable
80% Practically no difficulty, occasional missed characters
40% Considerable difficulty, many missed characters
20% Occasional words distinguishable
0% Undecipherable |
| |
|
| - STRENGTH |
S9
S7
S5
S3
S1 |
Very Strong trace
Strong trace
Moderate trace
Weak trace
Barely perceptible trace |
| |
|
| - QUALITY |
Q9
Q7
Q5
Q3
Q1 |
Clean signal - no visible unwanted sidebar pairs
One barely visible pair
One easily visible pair
Multiple visible pairs
Splatter over much of the spectrum |
|
