Setup Antenna Selector

Jim Hargrave W5IFP


1.1 Support

Logger32 currently supports three methods of automatically switching antennas:

Logger32 also supports manual operation of the antenna switch for testing the configuration Setup and the antenna switch hardware. The automatic antenna switch must be installed and Logger32 properly configured. See section 3 below: “Testing the Antenna switch”

1.2 Setup

This section covers setting up Logger32 to operate the remote programmed antenna switch. A simple antenna switch example is detailed the Appendix "Automatic Antenna Switch". 

There are two programming schemes available, Decimal and Binary. Both of these use the parallel port and provide a digital HIGH state (5V) on the respective line(s).

1)       Decimal…. This option allows up to 8 antenna lines. Logger32 will program the parallel port pins 2 thru 9.  The antenna numbers are in order starting with Pin # 2, antenna number 1, Pin # 3 is antenna #2…etc …with Pin # 9 being antenna #8. Only one pin is high at any given time. 

2)       Binary…. This option provides a 4-bit Binary output on the parallel port. Pins 2, 7, 8, & 9. The output is in BCD and allows up to 15 selected numbers. Pin # 2 is data line A (1), Pin # 7 is data line B (2), Pin number 8 is data line C (4) and Pin number 9 is data line D (8). The specific antenna number listed in the Bands/Mode chart will result in a BCD equivalent output.


From Main Menu, select the  "Setup" menu and from the Setup menu select "Antenna Selector".


The Antenna Selector dialog box will be displayed allowing the user to configure and monitor the automatic antenna selection process.

You will also note an LED with caption "Pin 14 (Radio switch)". This LED reflects which radio is in use when two radios are configured in Logger32. The LED will be green when Radio #1 is selected and will turn red when Radio #2 is selected. When the LED is green, pin 14 of the parallel port will have logic 1 (+5vdc). When the LED is red, pin 14 will have logic 0 (0vdc). This signal can be used to switch interface cables, microphones, and operating adapters between the two radios. It can also be combined with the antenna lines to switch antennas and linear amplifiers. Additional information for Pin 14 application is contained in the in the Hardware Setup portion of the Automatic Antenna Switch and SO2R sections. 

Note: The logic level of this pin can be reversed by checking the box “Invert pin 14”. This will result in logic HIGH when radio # 2 is selected.


Select the "Config" menu item and the Parallel Port address dialog box will appear. Enter the correct parallel port address for your computer and operating system and click  "OK".  Typical parallel port addresses are &H378 for LPT1 and &H278 for LPT2.

Note: Some PCI parallel port plug-in cards use an address other than the conventional LPT1 or LPT2 address. You should open the Device Manager and determine the exact address assigned to your parallel port, then enter that address in the Parallel port dialog box.


For Antenna switches that operate from a serial port, select the appropriate COM port number from the drop-down menu.


The following shows the drop down menu for antennas using OTRSP protocol. See details below in this section.



The following shows the drop down menu for microHAM antenna switch. Click on the Setup uHam port button and a drop down menu will appear. See the microHAM setup section for detailed setup.





From the Antenna Selector dialog box, select the default antenna menu item to display the default antenna list. Simply select the desired default antenna to be used for any frequency that is not defined in the Bandplan or does not have an antenna defined in the Bandplan. The last line allows the operator to select the last selected antenna and ensures that Logger32 will continue using the last selected antenna when the frequency goes out of a frequency defined in the Bandplan as having an antenna. As an example, assume the operator was on 20m and had a beam selected as the operating antenna. If the operator should move outside of the defined Bandplan segment, Logger32 would keep the same beam active until a frequency was entered that was defined in another segment of the Bandplan.


Click on the "Antenna name" and a list of the eight antenna positions will appear. Move the cursor to one of the positions and left-click to select the antenna to which you wish to assign a name.


This action will open another window with the space to assign a name to the antenna in the selected position. Type in the name of the antenna and click "OK". Repeat this process until you have named all the antennas you have connected to antenna switch.


Now, click "OK" and the configuration you have selected will be saved in the Logger32 INI file.

On the right side of the Antenna Selector dialog box is a series of LEDs that show which Parallel port pin number and associated antenna are selected. Note: this table shows the correlation of the antenna number and actual Parallel port hardware pin number. LEDs will turn Green indicating which antenna is active. You can open this window during operation to monitor the antenna switching activity and as an aid to troubleshooting the antenna control interface.

Antenna status can also be monitored from the Logger32 Lower Status Bar pane labeled "Antenna". Placing the mouse cursor over this pane will pop up a yellow Hint Box with the currently selected antenna.


After the Antenna Selector setup has been completed, the user must edit the "Bands & Mode" setup to enter an antenna number in the aerial column of the appropriate frequency segments. See the section on setting up the Bandplan for detailed procedures.

 3. Testing the Antenna switch

To manually switch the antennas, tune the radio to a frequency that does not have an antenna designated in the Bandplan or just turn the radio OFF so no frequency will be displayed.

Open “Setup | Antenna selector” Click on “Default antenna”. Select an antenna and the antenna switch should make the selected antenna active. The LED display will show the active parallel pin number. Be sure and re-set to the desired default antenna after you have verified that the switch is working properly.