dBCalc: Signal Power & dB Comparison
KD WY5R & David KJ4IZW
JT65A on HF, or Terrestrial JT65, is a weak signal mode with it's roots in
EME/Moonbounce operations. It is a data mode designed to copy signals as
much as 15dB below the noise level. On HF, operators take this ability for
granted by using power levels which are not necessary. It is recommended
that you examine your logbook on a regular basis, and check your average
signal report. If you find that you consistently receive signal reports
better than -10 dB, you can safely lower your power to 1/4th or 1/8th of what
you currently use. The purpose of dBCalc is to provide an operator with
alternative power levels required to acheive other readable signal reports
with programs such as WSJT or JT65-HF.
To calculate alternative power levels, enter your current power output in
the TX Power box. Next, select the signal level you received from your
latest QSO. You will be presented with a list of power levels required for
other signal reports to the same station.
| Report |
Power |
| -01dB |
316.23 W |
| -02dB |
251.19 W |
| -03dB |
199.53 W |
| -04dB |
158.49 W |
| -05dB |
125.89 W |
| -06dB |
100.00 W |
| -07dB |
79.43 W |
| -08dB |
63.10 W |
| -09dB |
50.12 W |
| -10dB |
39.81 W |
| -11dB |
31.62 W |
| -12dB |
25.12 W |
| -13dB |
19.95 W |
| -14dB |
15.85 W |
| -15dB |
12.59 W |
| -16dB |
10.00 W |
| -17dB |
7.94 W |
| -18dB |
6.31 W |
| -19dB |
5.01 W |
| -20dB |
3.98 W |
| -21dB |
3.16 W |
| -22dB |
2.51 W |
| -23dB |
2.00 W |
| -24dB |
1.58 W |
| -25dB |
1.26 W |
| -26dB |
1.00 W |