About WSPR
WSPR - The network
The Weak Signal Propagation Reporter Network is a group of amateur radio operators using K1JT's MEPT_JT digital mode to probe radio frequency propagation conditions using very low power (QRP/QRPp) transmissions. The data collected are available to the public.
The WSPRnet web site provides a simple user interface for querying the database, a mapping facility, and many other features.
WSPR 2.0 - The program
WSPR (pronounced "whisper") stands for "Weak Signal Propagation Reporter".
The WSPR software is designed by Joe Taylor ( K1JT ) for probing potential radio propagation paths using low-power beacon-like transmissions. WSPR signals convey a callsign, Maidenhead grid locator, and power level using a compressed data format with strong forward error correction and narrow-band 4-FSK modulation. The protocol is effective at signal-to-noise ratios as low as -28 dB in a 2500 Hz bandwidth. Receiving stations with internet access may automatically upload reception reports to a central database - WSPRnet.
WSPR The protocol
The Weak Signal Propagation Reporter Network is a group of amateur radio operators using K1JT's MEPT_JT digital mode to probe radio frequency propagation conditions using very low power (QRP/QRPp) transmissions. The data collected are available to the public.
The WSPRnet web site provides a simple user interface for querying the database, a mapping facility, and many other features.
WSPR 2.0 - The program
WSPR (pronounced "whisper") stands for "Weak Signal Propagation Reporter".
The WSPR software is designed by Joe Taylor ( K1JT ) for probing potential radio propagation paths using low-power beacon-like transmissions. WSPR signals convey a callsign, Maidenhead grid locator, and power level using a compressed data format with strong forward error correction and narrow-band 4-FSK modulation. The protocol is effective at signal-to-noise ratios as low as -28 dB in a 2500 Hz bandwidth. Receiving stations with internet access may automatically upload reception reports to a central database - WSPRnet.
WSPR The protocol
| Specifications of the WSPR Protocol | ||
|---|---|---|
| Standard message | callsign + 4-digit locator + transmitted power level [dBm] | |
| Standard message components after lossless compression | 28 bits for callsign, 15 for locator, 7 for power level, 50 bits total | |
| Forward error correction (FEC) | convolutional code with constraint length K=32, rate r=1/2 | |
| Keying rate | 1.4648 baud | |
| Number of binary channel symbols | 162 | |
| Modulation | continuous phase 4-FSK, tone separation 1.4648 Hz | |
| Occupied bandwidth | about 6Hz | |
| Synchronization | 162-bit pseudo-random sync vector | |
| Data structure | each channel symbol conveys one sync bit (LSB) and one data bit (MSB) | |
| Duration of transmission | 110.6 s | |
| Minimum S/N for reception | around -28 dB on the WSJT scale (2500 Hz reference bandwidth). | |
LZ0DLS - The beacon
| Specifications of the LZ0DLS | ||
|---|---|---|
| WSPR message | LZ0DLS KN12 10
Source-encoded message (50 bits, hex): 94 7B 7B 86 EB 92 80
Data symbols:
1 1 0 0 1 0 0 0 0 0 0 0 1 0 0 0 1 0 1 1 0 0 0 1 1 1 0 1 1 1
0 1 1 0 1 1 1 1 1 0 1 1 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 1
1 1 1 0 0 0 0 0 1 1 0 1 0 1 1 1 0 1 0 0 1 0 0 1 0 1 0 0 0 0
1 1 1 1 1 1 1 0 1 0 0 0 0 0 1 0 1 0 0 0 0 1 1 1 0 0 0 0 0 1
1 1 1 1 1 0 0 0 1 0 0 1 1 1 0 1 1 0 1 0 0 1 0 1 1 0 0 0 0 0
1 0 0 1 1 0 0 1 1 1 0 0
Sync symbols:
1 1 0 0 0 0 0 0 1 0 0 0 1 1 1 0 0 0 1 0 0 1 0 1 1 1 1 0 0 0
0 0 0 0 1 0 0 1 0 1 0 0 0 0 0 0 1 0 1 1 0 0 1 1 0 1 0 0 0 1
1 0 1 0 0 0 0 1 1 0 1 0 1 0 1 0 1 0 0 1 0 0 1 0 1 1 0 0 0 1
1 0 1 0 1 0 0 0 1 0 0 0 0 0 1 0 0 1 0 0 1 1 1 0 1 1 0 0 1 1
0 1 0 0 0 1 1 1 0 0 0 0 0 1 0 1 0 0 1 1 0 0 0 0 0 0 0 1 1 0
1 0 1 1 0 0 0 1 1 0 0 0
Channel symbols:
3 3 0 0 2 0 0 0 1 0 0 0 3 1 1 0 2 0 3 2 0 1 0 3 3 3 1 2 2 2
0 2 2 0 3 2 2 3 2 1 2 2 2 2 2 0 1 0 3 3 0 0 3 1 0 3 0 2 2 3
3 2 3 0 0 0 0 1 3 2 1 2 1 2 3 2 1 2 0 1 2 0 1 2 1 3 0 0 0 1
3 2 3 2 3 2 2 0 3 0 0 0 0 0 3 0 2 1 0 0 1 3 3 2 1 1 0 0 1 3
2 3 2 2 2 1 1 1 2 0 0 2 2 3 0 3 2 0 3 1 0 2 0 2 2 0 0 1 1 0
3 0 1 3 2 0 0 3 3 2 0 0
| |
| CW ID | LZ0DLS WSPR BEACON KN12PQ 600 ASL | |
| Operating Frequency : | 10.140 250 MHz | |
| Power supply : | 200mA @ 12V | |
| Power : | 10 mW ( 10dBm ) | |
| Coordinates: | 23 15' 26"E; 42 41' 11" N | |
Beacon Hardware
- The Core:
- Silicon Labs Si570 CAC000141DG DCO. Decode chip's part number
- Seeduino (v2.12) - Atmel MCU ATmega168 based board
- Time refference: cheap GPS receiver module by Rockwell (thanks to eBay :-) ) + external antenna
- Power Amplifier - (planned) 2SC1970(driver) + IRF510 (final stage)
The design of the amplifier is borrowed from: HF SDR Transceiver-AVALA-01 by YU1LM
similar solutions: - Antenna - I dont know yet!?
The beacon firmware is coded in C, using Arduino 0022 IDE (source code will be posted later)
Why DLS ? The suffix of the callsign stands for "Dobrata Lamya Spaska". Translated directly to English it means "The good dragon Spaska" :-))
Female dragon Spaska is a mythical hero of Bulgarian fairy tales and also involved in many jokes of recent times. She is good at heart and LZ0DLS just whispers her name instead of roaring and scaring people. :-)
Step-By-Step:
2 Nov 2011 A request was sent to the Communications Regulation Commission (CRC) for a license for LZ0DLS.
3 Nov 2011 The first WSPR message was transmitted (5 mW power), received at the other side of my desk and successfully decoded. Transmissions normally begin at one second after an even UTC minute (i.e. hh:00:01, hh:02:01). During the first tests, start and stop timing was performed by hand :-). Data symbols, sync symbols and resultant channel symbols were calculated by WSPRcode.exe
4 Nov 2011 A frequency adjustment procedure was performed. Thomas MARTIN (DF7TV) does an excellent job of describing the correct setup procedure for the Si570 in his notes on his Si570/PICAXE experiments. However, in my experience, there was no need to measure Fstart. I simply measured the output frequency of the Si570 using an FT897D after warm-up. The signal was aproximably 1kHz higher than expected. I then recaulatued the the register 7 to 12 values to reduce the frequency to the desired value. The step between channel frequencies (tone separation) was 1.4648 Hz (0x673). Calculations were performed using Silicon Labs Programmable Oscillator Software.
5 Nov 2011 LZ0DLS learned Morse code and can now send CW ID (as required by the regulations for amateur radio services in Bulgaria)
6 Nov 2011 LZ0DLS now capable of utilizing GPS satellites to synchronize its clock via the GPS Module Rockwell
11 Nov 2011 The national regulatory agency (The Communications Regulation Commission or CRC) issued a license to LZ0DLS.
12 Nov 2011 First "on-air" tests were performed
Pout = 10 mW (yes, only 10 mW or less)
Antenna - dipole for 40m band
First logged spots at WSPRnet:
(callsign used during tests - LZ1NY)
15 Nov 2011 5 Watts PA (2SC1970 + IRF510) is ready to be tuned and tested. Does it work? I don't know yet....Antenna - dipole for 40m band
First logged spots at WSPRnet:
(callsign used during tests - LZ1NY)
2011-11-12 19:56 LZ1NY 10.140204 -23 0 KN12pq 0.01 PA3DPN JO21ot 1693 313 2011-11-12 19:56 LZ1NY 10.140244 -15 0 KN12pq 0.01 ON7KO JO21ce 1722 310
19-20 Nov 2011 Too busy to work with LZ0DLS this weekend due to a LZ DX Contest :-)
....... etc.....etc.....etc
19 Jan 2012 Two months later... the PA is still not ready ... so LZ0DLS began at 10mW.
"weak signal" means - weak signal :-)
for some months LZ0DLS was off line due to hardware crash caused by statics :-( The most expensive part Si570 chip was damaged!
4 Feb 2013 LZ0DLS is on-air again!
First spots >>>
Unique reporters, ordered by distance >>>
Links
References:K1JT's WSPR Home Page
Weak Signal Propagation Reporter Network
NMEA data
Si570 - Silabs I2C programmable oscillators(XO)
Where to buy:
SEEDUINO - Arduino compatible microcontrollers from SeeedStudio
Silicon Labs Si570 chip from SDR-Kits
Software:
Arduino IDE Software
Silicon Labs Programmable Oscillator Software
WSPR encoding and channel symbol generation tool - WSPRcode.exe by K1JT
73 ! Victor / LZ1NY