This plug-in makes it possible to add a powerful analog and digital Signal Strength Meter to any WiNRADiO 1000/1500/3000 and G3 series receiver. The signal level can be displayed in microvolts, dBm or S-units. For microvolts, either RMS value or peak-to-peak values can be displayed.

This facility is useful wherever it is necessary to measure absolute signal strength levels. A logging function is also included, where the measured values are stored in a file with user-definable intervals.

The S-meter can display either immediate values (in any of the three selectable units) or peak values, determined over user-definable time periods.

The S-meter relies on calibration values stored in user-editable tables stored in separate files. These tables contain conversion constants using which the raw values arriving from a receiver's internal A/D converter are translated into dBm units (from where they are recalculated in microvolts or S-units as required).

Tables with average calibration values for WiNRADiO receivers are included with this plug-in. These tables will typically provide signal level measurement accuracy within 5dB. Improved accuracy can be achieved by editing the calibration cables for each individual receiver. This can be accomplished using a separate program called S-meter Plug-in Calibrator.

The S-meter panel can be divided into three parts: The top-bar menu, the analog and digital meter, and the various controls.

Top-bar Menu

The File menu contains the Open Calibration Table function, using which it is possible to select user-defined calibration tables. The Save Log and Save Log As functions are used to store log files on the disk.

The Options include Stay On Top and Set Integration Time which makes it possible to adjust the time interval for peak level measurements.

The Analog Meter

The Analog Meter displays either immediate or peak value of signal strength in selected units.

The Digital Meter

The Digital Meter displays either immediate or peak values of the signal strength. If peak values are selected, the first such value will be available only after the initial time interval; in the meantime, the display will show the immediate signal strength and the word "WAIT" will appear temporarily at the bottom of the display.

This display also informs the user when the value of signal strength is being logged: in this instant, a small circle appears at bottom left of the display.

Controls

dBm - the signal level is shown in dBm units
S - the signal level is shown in S-units
uV - the signal level is shown microvolts (or, for values over 1000 uV, in millivolts)

Inst - instantaneous signal level is shown
Peak - peak value is shown (over user-definable time interval)

If uV measurement unit is selected, there are the following additional options:

RMS - the signal level is displayed as RMS value
P-P - the signal level is shown as Peak-To-Peak value

Signal Strength Logging

The signal level values are logged if the option Log Level Every... is checked. The user needs to specify how often this value should be logged. Log can be deleted by Clear Log button and saved by Save Log As button. The default file name is as follows:

SL-[year/month/date]-[hour/minute/second].log.