Heathkit SB-10 Series Troubleshooting Manual page 57

Band Frequency
80 3,750
40 7,250
20 14,250
15 21,250
10 28,750
Table 5. Signal to Noise Ratio (S+N/N)
If the CW Filter is installed, as a bonus measurement, you might wish to switch to CW
mode, and tune to the signal generator (if the CS Filter is not installed, you can do this
in SSB mode). Keep reducing the generator's output until you think that the signal
represents the weakest signal you could copy. Record the signal generator level. This
can be considered the "minimum discernible signal."
Since there is some difference between the signal level that you consider readable and
my assessment, there is more room for operator-to-operator variance here. (We could
make this more quantifiable by saying that the MDS is 6 dB (S+N)/N but in truth, it is
whatever your ears tell you it is.)
Band Frequency
80 3,750
40 7,250
20 14,250
15 21,250
10 28,750
Table 6. Minimum Discernible Signal (MDS)
Signal to Noise Ratio (SNR)
Signal Gen Output (dBm)
Signal Gen Output (dBm)
Signal Gen Output ( volts)
Signal Gen Output ( volts)
Page 57