S Meter Calibration

Once you have calibrated the frequency and SWR and Power Meter of your Wolf, you might want to adjust the S Meter so that the displayed signal level reflects the actual signal strength.

About S Meter

According to Wikipedia, an S meter (signal strength meter) is an indicator often provided on communications receivers, such as amateur radio or shortwave broadcast receivers. The scale markings are derived from a system of reporting signal strength from S1 to S9 as part of the R-S-T system. The term S unit refers to the amount of signal strength required to move an S meter indication from one marking to the next.

S Meter values correspond to the signal RMS amplitude in a 50 Ohm load expressed in micro-volts or dBm.

There are two different scales, one for HF and another for VHF/UHF:

Reference signal with Tiny SA

To calibrate a S Meter we need a reference signal. Tiny SA is a perfect tool for that with it's signal generator feature.

Using the Low Output of the Tiny SA or Tiny SA Ultra, we can generate a sine wave of the desired frequency and set it's amplitude directly in dBm:

Wolf S Meter calibration

The S Meter of the Wolf can be adjusted per band in the Menu\Calibration\RX menu (check here if you can't find the Calibration menu):

Here are the available bands:

• S METER LHF: 160m / 80m,
• S METER MHF: 40m / 30m / 20m / 17m,
• S METER HHF: 15m / 12m / 10m,
• S METER 6M: 6m,
• S METER 2M: 2m,
• S METER 1.25M: 1.25m,
• S METER 70CM: 70cm,
• S METER 23CM: 23cm,
• S METER 6CM: 6cm,
• S METER 3CM: 3cm,
• S METER 1_2CM: 1.2cm.

You will have to calibrate the S Meter for all the bands that you are using.

Calibration procedure

To calibrate the S Meter of each band we will:

1. Feed the Low Output if the Tiny SA to the appropriate antenna input of the Wolf,
2. Set the Tiny SA in Signal Generator mode,
3. Set the Tiny SA frequency in the middle of the band we want to calibrate,
4. Set the Tiny SA level to -53 dBm,
5. Set the Tiny SA Low Output to ON,
6. Set the Wolf frequency to the same value and the mode to AM (for all bands),
7. Disable LNA on the Wolf (PRE button off)
8. Adjust the S METER value for the band to calibrate in the calibration menu so that the S value is S9+20dB for HF or S9+40dB for VHF.

Here are some examples:

• LHF band:

• HHF band:

• 2m band: