Tools
Short calculators for everyday use at the station.
Locator and distance
Convert coordinates to a Maidenhead locator and work out distance and bearing between two stations.
Distance—
Bearing—
Reverse bearing—
Coordinates → locator—
Power and dB
Watts, dBm, dBW and decibel ratios.
dBW—
Difference in dB—
S-units—
Band plan
IARU Region 1 HF segments with the usual modes.
| Band | Segment | Mode | Wavelength | Half-wave dipole | |
|---|---|---|---|---|---|
| 160 m | 1 810 – 1 838 kHz | CW | 164,36 m | 78,89 m | Calculate an antenna |
| 1 838 – 1 843 kHz | Digital | 162,89 m | 78,19 m | Calculate an antenna | |
| 1 843 – 2 000 kHz | SSB | 156,02 m | 74,89 m | Calculate an antenna | |
| 80 m | 3 500 – 3 570 kHz | CW | 84,81 m | 40,71 m | Calculate an antenna |
| 3 570 – 3 600 kHz | Digital | 83,62 m | 40,14 m | Calculate an antenna | |
| 3 600 – 3 800 kHz | SSB | 81,02 m | 38,89 m | Calculate an antenna | |
| 60 m | 5 351,5 – 5 354 kHz | CW | 56,01 m | 26,88 m | Calculate an antenna |
| 5 354 – 5 366 kHz | SSB | 55,93 m | 26,85 m | Calculate an antenna | |
| 40 m | 7 000 – 7 040 kHz | CW | 42,71 m | 20,50 m | Calculate an antenna |
| 7 040 – 7 060 kHz | Digital | 42,52 m | 20,41 m | Calculate an antenna | |
| 7 060 – 7 200 kHz | SSB | 42,05 m | 20,18 m | Calculate an antenna | |
| 30 m | 10 100 – 10 130 kHz | CW | 29,64 m | 14,23 m | Calculate an antenna |
| 10 130 – 10 150 kHz | Digital | 29,57 m | 14,19 m | Calculate an antenna | |
| 20 m | 14 000 – 14 070 kHz | CW | 21,36 m | 10,25 m | Calculate an antenna |
| 14 070 – 14 099 kHz | Digital | 21,29 m | 10,22 m | Calculate an antenna | |
| 14 101 – 14 350 kHz | SSB | 21,07 m | 10,12 m | Calculate an antenna | |
| 17 m | 18 068 – 18 095 kHz | CW | 16,58 m | 7,96 m | Calculate an antenna |
| 18 095 – 18 109 kHz | Digital | 16,56 m | 7,95 m | Calculate an antenna | |
| 18 111 – 18 168 kHz | SSB | 16,53 m | 7,93 m | Calculate an antenna | |
| 15 m | 21 000 – 21 070 kHz | CW | 14,25 m | 6,84 m | Calculate an antenna |
| 21 070 – 21 110 kHz | Digital | 14,21 m | 6,82 m | Calculate an antenna | |
| 21 151 – 21 450 kHz | SSB | 14,07 m | 6,76 m | Calculate an antenna | |
| 12 m | 24 890 – 24 915 kHz | CW | 12,04 m | 5,78 m | Calculate an antenna |
| 24 915 – 24 929 kHz | Digital | 12,03 m | 5,77 m | Calculate an antenna | |
| 24 931 – 24 990 kHz | SSB | 12,01 m | 5,77 m | Calculate an antenna | |
| 10 m | 28 000 – 28 070 kHz | CW | 10,69 m | 5,13 m | Calculate an antenna |
| 28 070 – 28 190 kHz | Digital | 10,66 m | 5,12 m | Calculate an antenna | |
| 28 225 – 29 700 kHz | SSB | 10,35 m | 4,97 m | Calculate an antenna | |
| 6 m | 50 000 – 50 100 kHz | CW | 5,99 m | 2,88 m | Calculate an antenna |
| 50 100 – 50 300 kHz | SSB | 5,97 m | 2,87 m | Calculate an antenna | |
| 50 300 – 50 400 kHz | Digital | 5,95 m | 2,86 m | Calculate an antenna |
These results are a good starting point for cutting wire. Real ground, nearby objects and the feedline always shift resonance a little: cut a few centimetres long and trim while measuring with an analyser.