Expansion Kit Features

See the Assembly Manual for a full list of items included with the Expansion Kit.

The Expansion Kit includes a number of useful features, such as the ability to add additional analog meters to MB-1. It also includes accessories that increase the functionality of MB-1. Some of these accessories are shown below.


Analog Meters

The Expansion Kit allows you to add external analog Panel Meters. Any DC Analog Meter with a full scale current of 1 mA or less can be added to MB-1 via the rear panel RCA jacks. MB-1 calibration routines allow you to use analog meters with linear scales, non-linear scales, and crossneedle meters. Once calibrated, the parameters are stored in EEProm for easy recall. Have multiple stations in your shack? Place an analog meter at each station. It is also possible to remotely locate a Digital Panel Meter, which provides a digital display. An example is shown below.

Amateur Radio related meters are readily available on eBay and other websites. The meter shown above is used in a "Generic Meter" Application using an analog sensor to measure temperature

External High Visibility 7-Segment Display 

Connect up to two Hi-Visibility 7-segment LED displays via the rear panel IDC connectors. The 7-segment display is easily readable at a distance. It can be configured with the same flexibility as the four internal 7-segement LED display modules, allowing you to specify the parameter to be displayed, and to turn leading zero suppression on or off. You provide the enclosure for the external display modules.

One 1.5 inch External 7-Segment display is included with the Expansion Kit.

The external 7-segment module has 2 IDC jacks, J1 and J2. Use the J1 jack when connecting the module to MB1. J2 is not used.


External High Visibility Bar Graph


MB-1 supports a Hi-Visibility external Bar Graph LED display as well. This external Bar Graph Module is easily readable at a distance. It can be configured with the same flexibility as the internal Bar Graph on MB-1's LCD, providing you with the ability to specify the parameter to be displayed, to turn the "sticky bar" on or off, and to process the Bar Graph Measurements with the Bar Graph AutoMax feature.

One External Bar Graph module is included with the Expansion Kit.

The external Bar Graph module has 2 IDC jacks, J1 and J2. Use the J1 jack when connecting the module to MB1. J2 is not used.
For the normal left-to-right display, orient the Bar Graph module as shown above.


Simple Mounting Arrangement for External Displays

An inexpensive acrylic picture frame (5.5 inches wide) is being used to mount the external displays. Black construction paper
or cardboard is placed in the insert after the cutouts for the displays are made. Window tint is used to to cover the cutouts.

(Ghosting of unlit segments below is a photo artifact).


MB-1 is being run with the simulator. (Full Scale power = 2000 w, with variable SWR 2.5 - 3.5)

Display Configuration:
External Bar Graph - Instantaneous Power
External 7-Segment Display - SWR

D1 - Selected Coupler
D2 - Band
D3 - Min SWR
D4 - Max SWR


A more professional look!

Thanks to WB4TC for the next two pics





MB-1 Supports the External Bar Graph and the Full
Family of 7-Segment Display Modules shown Below

The 1.5 inch External 7-Segment LED module described above that is supplied with the MB-1 Expansion Kit is a member of a family of other large 7-Segment LED displays manufactured by Sure Electronics. Sure Electronics sells 7-Segment modules up to 7 inches high!   Do a store search on eBay for “Information Boards”. The prices of these modules are very reasonable.

If you have a special application where you need really large 7-segment External Displays, such as an industrial application or club environment, you can add 1.8 inch, 2.3 inch, 4 inch or 7 inch LED modules to MB-1. The User's Manual contains full details.

To use these larger SURE modules, you need to install the "Large 7-Segment Display" Option in MB-1. For a limited time, this option is being included with the Expansion Kit option at no additional cost. Since some of the External Modules require 5 volt power and others require 12 volt power, you must configure two internal jumpers inside the MB-1 control head to provide the correct DC voltage for each External Display modules. (The larger modules require 12 volts.)  Again, this is covered in detail in the User Manual.


40 Segment Bar Graph Module (1 piece included with Expansion Kit)


1.5 Inch Module (1 piece included with Expansion Kit)


1.8 Inch Module


2.3 Inch Module


Two - 4 Inch Modules - connect in cascade


Four - 7 Inch Modules - connect in cascade

MB-1 Interfaces to the Full Family of SURE Electronics
 Hi-Visibility 7-Segment LED Display Devices



Connecting a Remote Digital Display to MB-1


It is possible to use an analog voltmeter module with a digital display (a Digital Panel Meter) so that it can be located remotely from MB-1 just like an analog meter can. As shown below, MB-1 has 3 dual D-to-A converters that are driven by the software to generate DC analog signals for driving analog meters connected to MB-1. In the example below, the first D-to-A converter is being used to drive both needles of the internal MB-1 analog meter. The second D-to-A converter is being used to drive both needles of an external crossneedle meter movement (the meter movement from a Daiwa meter). The first port on the third D-to-A converter is being used to drive an external single needle meter movement. Finally, the second port on the last D-to-A converter is connected to a Digital Panel Meter module. This module can be calibrated using the same Panel Meter calibration setup routine that would be used for a conventional analog meter.

These Digital Panel Meters are easily found on the Internet, and are relatively inexpensive. The one shown in the example below is a SURE 3 digit voltmeter/ammeter with a number of user configurable settings. If the Digital Panel Meter module is configured as a voltmeter with a full scale reading of 1.999 volts, it can be used to display values of 0 - 1999 watts because the decimal point for this module is set statically (by applying a ground to one of the four decimal points), and can therefore be totally disabled for this application.

When calibrating the Panel Meter Port, the following settings are used:

  • Scale Type: Linear
  • Number of Power Scales: 1
  • Power Scale - Full Scale Value: 1999
  • Number of SWR Scales: 0

During the Panel Meter setup routine, when instructed to "ADJUST METER POT Past FS Deflection", adjust the Panel Meter Trim Pot slightly above the full scale value of Digital Panel Meter until the display indicates an overrange condition (> 2 volts in this example). This will ensure that the D-to-A converter has adequate range to drive the Digital Panel Meter to its full scale value.

During the actual calibration, when instructed to "ADVANCE NEEDLE TO FS VALUE", use the front panel pot, or the UP/DOWN menu buttons to set the voltage seen by the Digital Panel Meter to the point where the display reads its maximum value (1999 in this case). You now have a remote digital display whose numeric values will track the measurement being directed to that "Panel Meter" by the MB-1 software.


  • Remember that these Digital Panel Meters are really just voltmeters reading an analog signal, and will therefore be subject to some jitter. In this example, each watt corresponds to only 1 millivolt. If you are running lower power, for example 100 watts, you could set the full scale value to 200 watts, and most jitter will be limited to the lower resolution digit (tenths).
  • The response time of many of these voltmeter modules is somewhat slow - in the order of a half second or so. If you use this arrangement to measure key down power during tune up, or if you set the display mode of this module to display Peak Power with a peak hold time of 2 seconds or more, you should be able to get good results.

To minimize jitter, use shielded cable, and install an RC filter at the Panel Meter input.


Digital Panel Meters on eBay