S-Meter
Received signal strength plots

Newport Receiver Signal Strength Indications

S-Meter calibration and signal strength plot interpretation

Kenwood R-5000 and Website S-Meter Plot Calibrations
There is no official industry standard, but most communication receiver manufacturers consider S9 to be 50 microvolts of radio-frequency voltage across the antenna terminals. Each S-Unit below 50 microvolts generally is considered to be 6dB (1/2 voltage, 1/4 power) lower. However, actual S-Meter calibration against those generally accepted standards tends to be very poor with most receivers.

S-Meter calibration of the Kenwood R-5000 at this website was measured with laboratory-quality test equipment. The results are shown in the table below. Even though the built-in analog S-Meter calibration is not very good, it is better than for most receivers. We correct the analog meter calibration errors in software after analog to digital data conversion, so that the calibration of the S-Meter plot at this website is correct to within a fraction of a dB for both HF and VHF.

Kenwood R-5000 Receiver Website
Standard S-Meter Reading HF VHF S-Meter Plot
50.00mv S9+60 Off-Scale Off-Scale +60
15.81mv S9+50 S9+60 Off-Scale +50
5.00mv S9+40 S9+55 Off-Scale +40
1.581mv S9+30 S9+45 Off-Scale +30
500uv S9+20 S9+35 Off-Scale +20
158.1uv S9+10 S9+22 Off-Scale +10
50uv S9 S9+10 S9+15 S9
25uv S8 S9+5 S9+8 S8
12.5uv S7 S8 S9+2 S7
6.3uv S6 S6 S7.5 S6
3.2uv S5 S4 S5 S5
1.6uv S4 S1 S3.5 S4
0.8uv S3 <S1 S3 S3
0.4uv S2 <S1 S1 S2
0.2uv S1 <S1 <S1 S1

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