The software will enter the coupler calibration setup routine bringing up the screen to the right. Press the UP or DOWN buttons (M1 or M2) to select the Coupler you want to calibrate. (In this example, coupler 4 has been selected) Then press SELECT (M3).

Make sure you use the UP/DOWN "buttons" represented by the first two menus choices on the top line of the LCD using the MENU-1 and MENU-2 buttons, and not the buttons with the Up-Scroll and Down-Scroll silkscreen labeling.

If the Coupler that you selected was previously calibrated, you are given the option to erase the previous settings or to EDIT the current settings.

If you want to perform a new calibration as we do here, press YES (M1) to erase the old settings. If, instead, you wanted to EDIT the settings of a previous calibration, you would press NO (M2)

Since we are doing a new calibration, we do not use the EDIT function in this example, but the EDIT prompt (had you chosen NO) is displayed at the end of this table for completeness.

This screen specifies the type of calibration to be performed on the selected coupler port. The choices are PWR (RF Power Coupler), AMPS (RF Ammeter coupler), or GENER (when using MB-1 with Analog Sensors). Since we are calibrating a power coupler, select PWR (M1).

The screens on the right aid in adjusting the coupler's FWD port trim pot for maximum sensitivity without overdriving the Amp/Mux in MB-1.

Typically, to adjust the FWD port trim pot, you set the transmit power to the full scale value you want to calibrate the coupler at (which would be 1000 watts in this example), and then adjust the FWD trim pot until the FWD ADC reading on the LCD reads approximately 30,000 - a value slightly below the max Amp/Mux 15 bit value of 32,736 to guarantee some margin.

However, since we do not have a transmitter capable of outputting 1000 watts in our sample setup, we consult the User's Manual to determine  the value that should be used to adjust the trim pot to when using a power level below the FS value to adjust the coupler trim pot (This will likely be a typical case for many users.)

If you follow the formula in the User's Manual, when the desired FS value of the coupler is 1000 watts, and the power being applied to adjust the trim pot is 150 watts (a reasonable value for the Mark V), the FWD trim pot should be adjusted to an ADC value of approximately 11,600. This is an approximate setting. It is important that you be in the "ballpark" only for this step. It is better to err on the side of setting this value to a slightly lower value since the goal of this step is to prevent overdriving MB-1's input circuitry.

When the top screen in the right column is displayed, press any menu button (M1 - M4) to display the actual FWD and REFL ADC values being applied to the coupler FWD and REFL ports. This is shown in the second screen. This screen shows the ADC values (0) with no power applied.

The photo at the far right shows the screen when power is applied and the FWD trim pot is properly adjusted.

After adjusting the trim pot, remove transmit power. Then press any menu button to continue.

The User's Manual explains the details of the preloaded OEM tables. The MB-HF1 has its calibration table preloaded in EEProm. If you are using this coupler (or other couplers that may be supported by this feature in the future), the entire calibration table, including any band compensation calibration values, can be loaded into the coupler port you are calibrating simply by answering YES to this prompt, and then entering the OEM numeric code for the corresponding coupler. This eliminates the need to perform the point by point calibration steps listed below. (However, you still need to adjust the FWD and REFL trim pots as per the manual.)

Even though we could have used the OEM option for the MB-HF1 coupler in this example, we will answer NO to this prompt so that we can demonstrate the step-by step procedures below for performing a custom coupler calibration.
 

Use this screen to specify the Reference Band. This is the band you will use when performing the FWD power calibration. If your transceiver supports 80 meters, this is a good band to use.

The "Reference Band" holds the main calibration data, and is also used by the  band correction algorithms, since the correction table measurements for each band are made with respect to the calibration point measurements performed in the Reference Band.

This screen is used to specify the FS value you intend to use with this coupler. This information is used to determine the list of calibration points you will be offered during the  calibration procedure. (When we set the FS value to 1000 watts as shown to the right, no calibration points greater than 1000 watts will be offered for calibration during the actual calibration sequence.)

This FS value is also used to set the Full scale value that the Simulator will generate when the Simulator is used to generate simulated values for this coupler.

To calibrate each point, apply the nominal power as displayed on the LCD, using a transmitter and reference meter. Then press SAV (M1). The screens to the right show the prompt and the reference meter reading for the .1 watt calibration point.

Remember, you do not need to calibrate all of the calibration points within the FS range that you specified, but you must perform a calibration at least one power level for the software to consider the calibration valid.

To skip a calibration point and move to the next higher power  calibration point, simply press NXT (M2).

After each point is saved, the screen automatically advances to the next available calibration point. Use the PREV (M3) button if you need to go back to lower power calibration point for any reason. Use the DEL (M3 - short press) button to delete a calibration point (useful if you know that a calibration point has a significant error, and you do not want to recalibrate that point).

Note: You will achieve better accuracy by calibrating with a smaller number of accurate calibration points rather than with a larger number of poor quality calibration points.

A photo of the final calibration point (150 watts) is shown in the far right column. (We are ending here since we do not have a 1 Kw power source in this example.)

When you have saved the calibration data for all of the desired power points, terminate the current calibration session by pressing END (Long press to M4). This will allow you to save the calibration points below.

Convention: All menu choices that perform a single function (like SAV, NXT and PREV in the menu to the right) are requested with a short push of the corresponding menu button.
 
Since there are only four menu buttons (M1 - M4), those menus that have five choices like the one shown to the right on line 1 of the LCD are handled as follows. For this menu, the Last menu item DEL/END controls both the DELete function and the END calibration function. For these dual menu cases, you select the first function (DEL) with a short press of the corresponding menu button (M4 in this case). You select the second function (END) with a long press of the corresponding menu button (M4). 
 

After ending the reference calibration, the screen to the right presents you with the option to perform Band Calibration. Until you are comfortable with the basic (Reference Band) calibration described here, it is suggested that you skip this step by pressing NO (M2). You can EDIT this coupler table at a later time to add the band compensation points. (Your coupler will still be useable on all bands, but will make use of the single Reference Band calibration data in this case.)

Full details for performing Band calibration are given in the User's Manual.

The screen at the right is the SAVE prompt. To save the calibration data to EEProm, press SAVE (M1).

To abort without saving the current calibration data, press EXIT (M4).

The screen to the right confirms that the calibration data was saved to EEProm.

The software now gives you the option to EXIT (resuming normal meter operation) or to TEST the coupler. The TEST option displays the ADC values corresponding to the DC voltages on the FWD and REFL ports of the coupler.  Think of this as a simple continuity check to verify that the coupler you think is connected to this coupler port is actually connected properly, and that the magnitude of the displayed ADC values increase or decreases as power applied through the coupler increases or decreases.

To EDIT the existing FWD power calibration table (the Reference Band), press FWD (M1). This will bring you to the actual calibration sequence described earlier in the above example. Once in this mode, you can select one or more previously calibrated points and recalibrate them,  or you can select power points that were not previously calibrated, and include them in the coupler's calibration table.

To perform (or edit) band calibration, enter FREQ (M2). Band calibration is covered in detail in the User's manual.

Apply a reasonable power, for example 50 watts, as measured by the reference meter (the coax connections on the reference meter should not be left in the normal configuration).

Activate the RefCal (Reflected Channel Calibration) mode with a long press to M2. This places the meter in a special mode that is used solely to adjust the REFL coupler trim pot.

You will see the confirmation screen on the right (top line) indicating that the software has entered the Reflected Channel Calibration mode. The yellow LED on switch RefCal switch M2 will also flash repeatedly  to remind you that you are in this special calibration mode.
 

Adjust the REFL port trim pot until the reflected channel reading on the MB-1 display matches the reference power meter's reading.

Ignore any other readings on the MB-1 displays, such as the FWD or SWR reading when in this mode.

Click to Expand

When done adjusting the REFL channel trim pot, press the RefCal (M2) button (any duration).  A message will be displayed indicating that the software is exiting the Reflected Channel Calibration mode as shown on the screen to the right (line 1). The meter is now in its normal operating mode.

Turn the transmitter off.
 

As with all DISPLAY functions, first display the applicable menu  (Coupler Menu in this case) on line 4 of the LCD. Then select the coupler you want to display the calibration data for (coupler 4 in this example). Then press the DISP button (Top Right Button - Short press).

Page 1:

The display function starts and the first page of the Coupler calibration data is displayed on the LCD .

This data identifies the coupler number, the FS power, the number of calibration points you saved during the calibration sequence, and the FWD trim correction factor (not discussed here - see User's manual). 

Since this display has multiple pages, press the DISP button (short press). Each press advances to the next page of information.

The second screen displays the Reference Band that the coupler was calibrated at.

The screen to the right (and subsequent screens, depending upon the number of calibration points you performed the calibration at) displays the data for each calibration point, namely the nominal power level and the corresponding ADC value. This example assumes that seven power points were calibrated.

The last 3 calibration points are displayed on the screen to the right.

If band correction had been performed, this information would be displayed here.

The OEM table associated with the MB-HF1 coupler contains band correction data that you can view if you wish to see what this data looks like. Coupler 1 (factory default) is loaded with the calibration table for the MB-HF1 coupler (OEM coupler 1).

After the calibration data is displayed, the software gives you the option to EXIT (resuming normal meter operation) or to initiate a coupler TEST. This TEST function was described earlier in this example.

The meter now resumes normal operation.